NCL2801CFADR2G - APTINA IMAGING - Datasheet.Directory

September, 2019 − Rev. 3

1Publication Order Number:

NCL2801/D

Power Factor Controller,

High-Efficiency,

Enhanced for Lighting

NCL2801

The 8−pin PFC controller NCL2801 is designed to drive PFC boost

stages. It is based on an innovative Valley Count Frequency

Fold−back (VCFF) method. The circuit classically operates in

Critical conduction Mode (CrM) for high load values. When the load

decreases a Discontinuous Conduction Mode DCM is forced by

forcing a dead time which, by construction corresponds to a fixed

number of valleys. The lower the output power, the higher the number

of valleys corresponding to the dead time. After DCM works down to

6th valley switching and if the load continues to decrease, a dead time

is continuously added to the 6th valley. The end of additional dead time

is synchronized with the drain voltage valley. The maximum

switching period is limited to 36.5 ms. VCFF maximizes the

efficiency during DCM and light load. In particular, the stand−by

losses are reduced to a minimum. Like in FCCrM controllers, internal

circuitry allows near−unity power factor even when the switching

frequency is reduced. Housed in a SO−8 package, the circuit also

incorporates the features necessary for robust and compact PFC

stages, with few external components.

General Features

•Near−Unity Power Factor

•Critical Conduction Mode (CrM)

•Valley Count Frequency Fold−Back (VCFF)

•Peak Current Control Mode to Maintain a Proper Current Shaping in

VCFF Mode

•Fast Line / Load Transient Compensation (Dynamic Response

Enhancer) Option

•Brown−out Detection

•Two−level Line Feed−Forward (HL&LL)

•Valley Turn−on (No Valley Hoping by Construction)

•High Drive Capability: −500 mA / +800 mA

•VCC Range: from 10.5 V to 27 V

•Low Start−up Consumption for :

•[*C*]& [*D*] Option: Low VCC Start−up Level (12.5 V)

[*A*]& [*B*] Option: High VCC Start−up Level (17.0 V)

[*E*]& [*F*] Option: High VCC Start−up Level (10.5 V)

•This is a Pb−Free Device

www.onsemi.com

See detailed ordering and shipping information on page 25 of

this data sheet.

ORDERING INFORMATION

SOIC−8

CASE 751

L2801abc = Specific Device Code

A = Assembly Location

L = Wafer Lot

Y = Year

W = Work Week

G= Pb−Free Package

L2801abc

ALYW

MARKING DIAGRAMS

(Top Views)

MULT

GND

DRV

VCC

PIN CONNECTIONS

VCTRL

ZCD

NCL2801

www.onsemi.com

Safety Features

•Thermal Shutdown

•Non−latching, Over−Voltage Protection (3 Prog Levels)

•Over Current Limitation

•Low Duty−Cycle Operation if the Bypass Diode is

Shorted

•Open Ground Pin Fault Monitoring

•Pin CS shorted to GND or open Monitoring

•Pin ZCD open tested before controller starts

•Controller not allowed to start if MULT pin is left open

Typical Applications

•PC Power Supplies

•Lighting Ballasts (LED, Fluorescent)

•Flat TV

•All Off Line Appliances Requiring Power Factor

Correction

Several product configurations coded with three letters

(L1,L2, L3) marked on the package will be available

Table 1. NCL2801 1

LETTER CODING OF PRODUCT VERSIONS

L1Soft OVP (% of VREF)Fast OVP (% of VREF)

ÁÁÁÁÁÁÁÁÁÁ

ÁÁÁÁÁÁÁÁÁÁÁÁÁ

Disabled

ÁÁÁÁÁÁÁÁÁÁÁÁ

112.5

ÁÁÁÁÁÁÁÁÁÁ

ÁÁÁÁÁÁÁÁÁÁÁÁÁ

Disabled

ÁÁÁÁÁÁÁÁÁÁÁÁ

110.0

ÁÁÁÁÁÁÁÁÁÁ

C (default)

ÁÁÁÁÁÁÁÁÁÁÁÁÁ

105.0

ÁÁÁÁÁÁÁÁÁÁÁÁ

107.0

1. The NCL2801 SO8 package is marked L1L2L3

Table 2. NCL2801 2

LETTER CODING OF PRODUCT VERSIONS

L2 VCC Startup Level (V) DRE (After Startup) DRE (During Startup)

A 17.0 NO YES

B 17.0 YES YES

C 12.5 NO YES

D (default) 12.5 YES YES

E 10.5 NO YES

F 10.5 YES YES

2. The NCL2801 SO8 package is marked L1L2L3

Table 3. NCL2801 3

LETTER CODING OF PRODUCT VERSIONS

L3Brown−in & Brown−out Line Range Detection w/ 2−level Line Feed−Forward

ÁÁÁÁÁ

A (default)

ÁÁÁÁÁÁÁÁÁ

YES

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

YES

ÁÁÁÁÁ

ÁÁÁÁÁÁÁÁÁ

YES

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

ÁÁÁÁÁ

ÁÁÁÁÁÁÁÁÁ

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

YES

ÁÁÁÁÁ

ÁÁÁÁÁÁÁÁÁ

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

NCL2801

www.onsemi.com

DRV

VCTRL

MULT

ZCD

GND

VCC

EMI

Filter

AC line

LOAD

Vin Vbulk

Rsense

Cbulk

Rmult2

Cin

Rfb2

Rfb1

Rmult1

RZCD

Naux

RCS

VCC

Figure 1. NCL2801 Application Schematic

Table 4. NCL2801 3RD LETTER CODING OF PRODUCT VERSIONS

Number Name Function

1 FB

This pin receives a portion of the PFC output voltage for the regulation and the optional Dynamic Response

Enhancer (DRE) that drastically speeds−up the loop response when the output voltage drops below 95.5 % of

the desired output level.

FB pin voltage VFB is also the input signal for the (non−latching) Over−Voltage (OVP). The UVP comparator

prevents operation as long as FB pin voltage is lower than VUVPH internal voltage reference. A SOFTOVP com-

parator gradually reduces the duty−ratio when FB pin voltage

exceeds 105% of VREF (option dependent). If despite of this, the output voltage still increases, the driver is im-

mediately disabled by fast OVP if the output voltage exceeds x% of the desired level (option dependent)..

A 250−nA sink current is built−in to trigger the UVP protection and disable the part if the feedback pin is

accidently left open.

2 VCTRL

The error amplifier output is available on this pin. The network connected between this pin and ground adjusts

the regulation loop bandwidth that is typically set below 20 Hz to achieve high Power Factor ratios.

VCTRL pin is internally pulled down when the circuit is off so that when it starts operation, the power increases

slowly to provide a soft−start function.

VCTRL pin must not be controlled or pulled down externally.

Pulled to GND if BO and at startup (pseudo−soft start). Just a switch.

3 MULT

Multiplier input pin. This pin receives a scaled down rectified mains voltage by the means of a resistor voltage

divider connected between Vin and GND.

4 CS

This pin senses the MOSFET current in order to end the on−time when the current reaches the control value or

the maximum current limit.

Just before startup, the value of the resistance between CS pin and GND pin is sensed for determining the

VCTRL value of the CrM to DCM threshold.

5 ZCD This pin uses the auxiliary winding voltage to determine the inductor current zero crossing.

6 GND Connect this pin to the PFC stage ground.

7 DRV The high−current capability of the totem pole gate drive (−0.5/+0.8 A) makes it suitable to effectively drive high

gate charge power MOSFETs.

8 VCC

This pin is the positive supply of the IC. The circuit starts to operate when VCC exceeds 17.0 V ([*A*] & [*B*]

Versions) or 12.5 V ([*C*] & [*D*] Versions) or 10.5 V ([*E*] & [*F*] Options) and turns off when VCC goes below

10.0 V (typ) for [*C*] & [*D*] Options and below 9.0 V (typ) for [*A*] & [*B*] &[*E*] & [*F*] Options. After start−up,

the operating range is 10.0 V (or 9 V depending on option) up to 27 V.

NCL2801

www.onsemi.com

Table 5. MAXIMUM RATINGS TABLE

Symbol Pin Rating Value Unit

FB 1 Feedback Pin −0.3, +9 V

VCTRL 2 VCONTROL pin −0.3, Vctrl,max

(Note 3) V

MULT 3 Multiplier Input pin −0.3, +9 V

CS 4 CS Pin −0.3, +9 V

ZCD 5 ZCD Pin −0.3, VCC+0.3 V

DRV 7 Driver Voltage

Driver Current

−0.3, VDRV (Note 3)

−500, +800

VCC 8 Power Supply Input −0.3, + 27 V

Rqja

Power Dissipation and Thermal Characteristics

Maximum Power Dissipation @ TA=70°C

Thermal Resistance Junction to Air

300

180

°C/W

TJOperating Junction Temperature Range −40 to + 125 °C

TJ,max Maximum Junction Temperature 150 °C

TS,max Storage Temperature Range −65 to 150 °C

TL,max Lead Temperature (Soldering, 10s) 300 °C

MSL Moisture Sensitivity Level 1−

ESD Capability, HBM model (Note 4) > 2000 V

ESD Capability, Machine Model (Note 4) > 200 V

ESD,CDM 1000 V

3. “Vctrl,max” is the VCTRL pin clamp voltage. “VDRV” is the DRV clamp voltage (VDRVhigh) if VCC is higher than (VDRVhigh). “VDRV” is VCC

otherwise.

4. This device(s) contains ESD protection and exceeds the following tests: Human Body Model 2000 V per JEDEC Standard JESD22−A114E

Machine Model Method 200 V per JEDEC Standard JESD22−A115−A

5. This device contains latch−up protection and exceeds 100 mA per JEDEC Standard JESD78.

Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality

should not be assumed, damage may occur and reliability may be affected.

NCL2801

www.onsemi.com

Table 6. ELECTRICAL CHARACTERISTICS (Conditions: VCC = 18 V, TJ = −40°C to +125°C, unless otherwise specified) (Note 6)

Symbol Rating Min Typ Max Unit

START−UP AND SUPPLY CIRCUIT

VCC,on

Start−Up Threshold, VCC increasing:

[*E*] & [*F*] Versions

[*C*] & [*D*] Versions

[*A*] & [*B*] Versions

9.75

11.6

15.6

10.5

12.50

16.7

11.25

13.4

18.00

VCC,off

Minimum Operating Voltage, VCC falling

[*C*] & [*D*] Versions

[*A*] & [*B*] & [*E*] & [*F*]

9.3

8.4

10.0

9.0

10.7

9.6

VCC,rst

Voltage at which IC completely restarts

ICC drops to ~ ICC,start

(Min and Max values are guaranteed by functional testing)

6.50 7.2 7.80 V

VCC,hyst

Hysteresis (VCC,on − VCC ,off)

[*E*] & [*F*] Versions

[*C*] & [*D*] Versions

[*A*] & [*B*] Versions

0.75

1.25

6.00

1.6

2.5

7.7

3.0

3.75

ICC,start Start−Up Current, VCC = 9.4 V, below startup voltage 0 10 60 mA

ICC,op1 Operating Consumption, no switching. 0 0.4 1.00 mA

ICC,op2 Operating Consumption, 50−kHz switching, no load on DRV pin 1.0 2.00 3.00 mA

GATE DRIVE

tROutput voltage rise−time @ CL = 1 nF, 10−90% of output signal 15 30 90 ns

tFOutput voltage fall−time @ CL = 1 nF, 10−90% of output signal 10 20 50 ns

ROH Source resistance @ 200 mV under High VCC 4 10 20 W

ROL Sink resistance @ 200mV above Low VCC 2 7 15 W

VDRV,low

DRV pin level for VCC = VCC,off + 200 mV

(10−kW resistor between DRV and GND)

[*A*] & [*B*] & [*E*] & [*F*]

[*C*] & [*D*] Versions

8.6

9.6

9.2

VDRV,high DRV pin level at VCC = 27 V (RL = 33 kW & CL = 1 nF) 10 12 14 V

VDRV,L Maximum DRV voltage while forcing zero at DRV pin and injecting 10 mA

into DRV pin @ VCC = 12 V 0 100 200 mV

REGULATION BLOCK

VREF Feedback Voltage Reference 2.45 2.50 2.55 V

IEA Error Amplifier Current Capability (source and sink) 15 20 25 mA

GEA Error Amplifier Gain 110 200 290 mS

Vctrl,max Vctrl,min

VCTRL pin Voltage (Vctrl):

− @ VFB = 2 V (OTA is sourcing 20 mA)

− @ VFB = 3 V (OTA is sinking 20 mA)

4.4

0.4

4.5

0.5

4.6

0.6 V

CURRENT SENSE BLOCK

VCS_OCP(th)

Current Sense Voltage Reference for option w/o line level detection

[**B]&[**D] Options

At tLEB,OCP

0.97 1.07 1.19 V

VCS_OVS(th)

Current Sense Overstress Voltage Reference for option w/o line level

detection

[**B]&[**D] Options

At tLEB,OVS

1.45 1.60 1.78 V

VCS_OCP_LL(th)

Current Sense Voltage Reference when Low Line is detected

[**A]&[**C] Options

At tLEB,OCP

0.97 1.07 1.19 V

VCS_OVS_LL(th)

Current Sense Overstress Voltage Reference when Low Line is detected

[**A]&[**C] Options

At tLEB,OVS

1.45 1.60 1.78 V

NCL2801

www.onsemi.com

Table 6. ELECTRICAL CHARACTERISTICS (Conditions: VCC = 18 V, TJ = −40°C to +125°C, unless otherwise specified) (Note 6)

Symbol UnitMaxTypMinRating

VCS_OCP_HL(th)

Current Sense Voltage Reference when High Line is detected

[**A]&[**C] Options

At tLEB,OCP**

0.53 0.58 0.66 V

VCS_OVS_HL(th)

Current Sense Overstress Voltage Reference when High Line is detected

[**A]&[**C] Options

At tLEB,OVS

0.79 0.87 0.97 V

tLEB,OCP Leading edge Blanking Time for current control 125 200 275 ns

tLEB,OVS Leading edge Blanking Time for Overstress 50 100 150 ns

tOCP

Over−Current Protection Delay from VCS>VCS(th) to

DRV low

Test: VCS > VCS + 100 mV

10 40 200 ns

tWDG(OS) Watch Dog Timer in “OverStress” Situation 400 800 1200 ms

ZERO CURRENT DETECTION BLOCK

VCL(pos) ZCD positive clamp (VCC = 12 V, IZCD = 5 mA) 12.6 12.9 13.2 V

VZCD(th)H Zero Current Detection, VZCD rising 675 750 825 mV

VZCD(th)L Zero Current Detection, VZCD falling 200 250 300 mV

VZCD(hyst) Hysteresis of the Zero Current Detection Comparator 375 500 625 mV

IZCD,bias ZCD pin input leakage current 0 250 500 nA

tZCD (VZCD < VZCD (th )L) to (DRV high) 20 80 200 ns

tSYNC Minimum ZCD Pulse Width (Guaranteed by Design) −60 −ns

tWDG Watch Dog Timer

If no ZCD detected 80 200 320 ms

IZCD,pu Pull−up current source to detect ZCD open pin

At startup only 0.85 1 1.15 mA

VREF,ZCD,open Voltage reference to test ZCD pin short during startup 150 200 250 mV

MULTIPLIER

Kmult Multiplier Gain (Note 2) for option w/o line level detection

[**B]&[**D] Options 0.34 0.38 0.42 1/V

Kmult,HL Multiplier Gain (Note 2) when High Line is detected

[**A]&[**C] Options 0.22 0.24 0.28 1/V

Kmult,LL Multiplier Gain (Note 2) when Low Line is detected

[**A]&[**C] Options 0.72 0.80 0.88 1/V

Kmult,Ratio Ration between Kmult,LL and Kmult,HL

[**A]&[**C] Options 2.9 3.3 3.7

Koffset Koffset.Vton voltage added at the multiplier output

[**A]&[**C] Options (w/ Line Detection) 0.10 0.140 0.20

Koffset_nld Koffset.Vton voltage added at the multiplier output

[**B]&[**D] Options (w/o Line Detection) 0.040 0.075 0.12

Imult_pd Current pull−down on Mult pin 200 280 350 nA

Vmult_max Maximum MULT pin voltage

Controller disabled if MULT pin voltage goes above this threshold 2.88 3.2 3.52 V

MAXIMUM ON−TIME

tON,max,A,2 @ VCTRL = 4.50 V 26 30 36 ms

tON,max,A,1 @ VCTRL = 0.55 V 3.6 5 6.9 ms

NCL2801

www.onsemi.com

Table 6. ELECTRICAL CHARACTERISTICS (Conditions: VCC = 18 V, TJ = −40°C to +125°C, unless otherwise specified) (Note 6)

Symbol UnitMaxTypMinRating

RCS VALUE IDENTIFICATION REFERENCE VOLTAGES

IRCS Internal current sourced by CS pin into a 1% RCS resistor just before the

startup generates a voltage drop VCS 0.96 1.0 1.04 mA

VRCS,REF,1 Internal voltage reference for identifying the RCS resistor value

CS pin is said shorted to GND if VCS < VRCS,REF,1 20 50 100 mV

VRCS,REF,2 Internal voltage reference for identifying the RCS resistor value

RCS = 150 W if RCS,REF,1 < VCS < VRCS,REF,2 180 230 280 mV

VRCS,REF,3 Internal voltage reference for identifying the RCS resistor value

RCS = 330 W if VRCS,REF,2 < VCS < VRCS,REF,3 400 460 530 mV

VRCS,REF,4 Internal voltage reference for identifying the RCS resistor value

RCS = 620 W if VRCS,REF,3 < VCS < VRCS,REF,4 720 790 880 mV

VRCS,REF,5

Internal voltage reference for identifying the RCS resistor value

RCS = 1000 W if VRCS,REF,4 < VCS < VRCS,REF,5

CS pin open if VCS >VRCS,REF,5

RCS open do not allow the controller to start

1190 1300 1400 mV

FREQUENCY FOLDBACK THRESHOLDS & HYSTERESIS

VCTRL,th,12,1000 VCTRL threshold for valley1 to valley2 forcing @RCS = 1000 W1.971 2.19 2.409 V

VCTRL,th,23, 1000 VCTRL threshold for valley2 to valley3 forcing @RCS = 1000 W1.647 1.83 2.013 V

VCTRL,th,34, 1000 VCTRL threshold for valley3 to valley4 forcing @RCS = 1000 W1.332 1.48 1.628 V

VCTRL,th,45, 1000 VCTRL threshold for valley4 to valley5 forcing @RCS = 1000 W1.008 1.12 1.232 V

VCTRL,th,56, 1000 VCTRL threshold for valley5 to valley6 forcing @RCS = 1000 W0.693 0.77 0.847 V

VCTRL,th,65, 1000 VCTRL threshold for valley6 to valley5 forcing @RCS = 1000 W1.008 1.12 1.232 V

VCTRL,th,54, 1000 VCTRL threshold for valley5 to valley4 forcing @RCS = 1000 W1.332 1.48 1.628 V

VCTRL,th,43, 1000 VCTRL threshold for valley4 to valley3 forcing @RCS = 1000 W1.647 1.83 2.013 V

VCTRL,th,32, 1000 VCTRL threshold for valley3 to valley2 forcing @RCS = 1000 W1.971 2.19 2.409 V

VCTRL,th,21, 1000 VCTRL threshold for valley2 to valley1 forcing @RCS = 1000 W2.286 2.54 2.794 V

VCTRL,hyst, 1000 VCTRL hysteresis when changing forced valley @RCS = 1000 W300 356 420 mV

VCTRL,th,12,620 VCTRL threshold for valley1 to valley2 forcing @RCS = 620 W1.647 1.830 2.013 V

VCTRL,th,23, 620 VCTRL threshold for valley2 to valley3 forcing @RCS = 620 W1.413 1.570 1.727 V

VCTRL,th,34, 620 VCTRL threshold for valley3 to valley4 forcing @RCS = 620 W1.170 1.300 1.430 V

VCTRL,th,45, 620 VCTRL threshold for valley4 to valley5 forcing @RCS = 620 W0.927 1.030 1.133 V

VCTRL,th,56, 620 VCTRL threshold for valley5 to valley6 forcing @RCS = 620 W0.693 0.770 0.847 V

VCTRL,th,65, 620 VCTRL threshold for valley6 to valley5 forcing @RCS = 620 W0.927 1.030 1.133 V

VCTRL,th,54, 620 VCTRL threshold for valley5 to valley4 forcing @RCS = 620 W1.170 1.300 1.430 V

VCTRL,th,43, 620 VCTRL threshold for valley4 to valley3 forcing @RCS = 620 W1.413 1.570 1.727 V

VCTRL,th,32, 620 VCTRL threshold for valley3 to valley2 forcing @RCS = 620 W1.647 1.830 2.013 V

VCTRL,th,21, 620 VCTRL threshold for valley2 to valley1 forcing @RCS = 620 W1.890 2.100 2.310 V

VCTRL,hyst, 620 VCTRL hysteresis when changing forced valley @RCS = 620 W200 267 320 mV

VCTRL,th,12, 330 VCTRL threshold for valley1 to valley2 forcing @RCS = 330 W1.332 1.480 1.628 V

VCTRL,th,23, 330 VCTRL threshold for valley2 to valley3 forcing @RCS = 330 W1.170 1.300 1.430 V

VCTRL,th,34, 330 VCTRL threshold for valley3 to valley4 forcing @RCS = 330 W1.008 1.120 1.232 V

VCTRL,th,45, 330 VCTRL threshold for valley4 to valley5 forcing @RCS = 330 W0.846 0.940 1.034 V

NCL2801

www.onsemi.com

Table 6. ELECTRICAL CHARACTERISTICS (Conditions: VCC = 18 V, TJ = −40°C to +125°C, unless otherwise specified) (Note 6)

Symbol UnitMaxTypMinRating

VCTRL,th,56, 330 VCTRL threshold for valley5 to valley6 forcing @RCS = 330 W0.693 0.770 0.847 V

VCTRL,th,65, 330 VCTRL threshold for valley6 to valley5 forcing @RCS = 330 W0.846 0.940 1.034 V

VCTRL,th,54, 330 VCTRL threshold for valley5 to valley4 forcing @RCS = 330 W1.008 1.120 1.232 V

VCTRL,th,43, 330 VCTRL threshold for valley4 to valley3 forcing @RCS = 330 W1.170 1.300 1.430 V

VCTRL,th,32, 330 VCTRL threshold for valley3 to valley2 forcing @RCS = 330 W1.332 1.480 1.628 V

VCTRL,th,21, 330 VCTRL threshold for valley2 to valley1 forcing @RCS = 330 W1.494 1.660 1.826 V

VCTRL,hyst, 330 VCTRL hysteresis when changing forced valley @RCS = 330 W120 178 230 mV

VCTRL,th,12,150 VCTRL threshold for valley1 to valley2 forcing @RCS = 150 W1.008 1.120 1.232 V

VCTRL,th,23, 150 VCTRL threshold for valley2 to valley3 forcing @RCS = 150 W0.927 1.030 1.133 V

VCTRL,th,34, 150 VCTRL threshold for valley3 to valley4 forcing @RCS = 150 W0.846 0.940 1.034 V

VCTRL,th,45, 150 VCTRL threshold for valley4 to valley5 forcing @RCS = 150 W0.774 0.860 0.946 V

VCTRL,th,56, 150 VCTRL threshold for valley5 to valley6 forcing @RCS = 150 W0.693 0.770 0.847 V

VCTRL,th,65, 150 VCTRL threshold for valley6 to valley5 forcing @RCS = 150 W0.774 0.860 0.946 V

VCTRL,th,54, 150 VCTRL threshold for valley5 to valley4 forcing @RCS = 150 W0.846 0.940 1.034 V

VCTRL,th,43, 150 VCTRL threshold for valley4 to valley3 forcing @RCS = 150 W0.927 1.030 1.133 V

VCTRL,th,32, 150 VCTRL threshold for valley3 to valley2 forcing @RCS = 150 W1.008 1.120 1.232 V

VCTRL,th,21, 150 VCTRL threshold for valley2 to valley1 forcing @RCS = 150 W1.089 1.210 1.331 V

VCTRL,hyst, 150 VCTRL hysteresis when changing forced valley @RCS = 150 W35 89 135 mV

SWITCHING CYCLE DEAD TIME

tADT

Dead time added after 6

valley

Vctrl = 0.50 V

Vctrl = 0.77 V

0.1

−

0.4

FEED−BACK OVER AND UNDER−VOLTAGE PROTECTIONS (OVP)

RsoftOVP,C Ratio (Soft OVP Threshold, VFB rising) over VREF (Options [C**]) 103.5 105 106.5 %

RsoftOVP(HYST) Ratio (Soft OVP Hysteresis) over VREF .0.8 1.3 3.2 %

RfastOVP,A Ratio (Fast OVP Threshold, VFB rising) over VREF (Options [A**]) 108.5 112.5 116.5 %

RfastOVP,B Ratio (Fast OVP Threshold, VFB rising) over VREF (Option [B**]) 106.1 110 113.9 %

RfastOVP,C Ratio (Fast OVP Threshold, VFB rising) over VREF (Option [C**]) 103.2 107 110.8 %

RfastOVP(HYST) Ratio (Fast OVP Hysteresis) over VREF 3.0 4.0 5.7 %

IB,FB FB pin pull−down Current @ VFB = VOVP and VFB = VUVP

Pulls down the FB pin in case the pin is open (solder failure) 50 200 450 nA

DYNAMIC RESPONSE ENHANCER (DRE)

RDRE Ratio (DRE Threshold, VFB falling) over VREF 94.0 95.7 97.5 %

RDRE(HYST) Ratio (DRE Hysteresis) over VREF 0.8 2.0 3.0 %

IVCTRL,Startup

Current measured out of VCTRL pin (DRE current source

minus max OTA current)

@ VFB=1V (PFCOK=0 ⇔ Startup)

80 100 120 mA

IVCTRL,1,Steady

Current measured out of VCTRL pin (DRE current source

minus max OTA current )

@ VFB=1V (PFCOK=1 ⇔ Steady State)

[*B*], [*D*], [*F*] Product Options

160 200 240 mA

UNDER VOLTAGE PROTECTION / DISABLE

VUVPH UVP Threshold, VFB increasing 380 450 520 mV

VUVPL UVP Threshold, VFB decreasing 150 200 250 mV

NCL2801

www.onsemi.com

Table 6. ELECTRICAL CHARACTERISTICS (Conditions: VCC = 18 V, TJ = −40°C to +125°C, unless otherwise specified) (Note 6)

Symbol UnitMaxTypMinRating

VUVP(HYST) UVP Hysteresis 200 250 300 mV

BROWN−OUT PROTECTION AND LINE FEED FORWARD

VBOH Brown−In Threshold, Vmains increasing

Note: Vline,BOH,rms = 74, 80, 87 V assuming 1/Km = 144 725 787 860 mV

VBOL Brown−Out Threshold, Vmains decreasing

Note: Vline,BOL,rms = 64, 72, 78 V assuming 1/Km = 144 634 709 770 mV

VBO(HYST) Brown−Out Comparator Hysteresis 50 75 130 mV

tBO(blank) Brown−Out Blanking Time 36 50 67 ms

IVCTRL(BO) VCTRL pin sink current during BO condition 20 30 42 mA

VHL Comparator Threshold for Line Range Detection VMULT rising

Note: Vline,HL,rms = 157,165,174 V assuming 1/Km = 144 1.543 1.625 1.706 V

VLL Comparator Threshold for Line Range Detection VMULT falling

Note: Vline,HL,rms = 137,145,152 V assuming 1/Km = 144 1.350 1.422 1.493 V

VHL(hyst) Comparator Hysteresis for Line Range Detection 37 218 300 mV

tHL(blank) Blanking Time for Line Range Detection

(must stay below VLLfor 25 ms before changing to LL) 13 25 43 ms

THERMAL SHUTDOWN

TLIMIT Thermal Shutdown Threshold 150 − − °C

HTEMP Thermal Shutdown Hysteresis −50 −°C

6. The above specification gives the targeted values of the parameters. The final specification will be available once the complete circuit

characterization has been performed.

7. In CrM mode, Gmult = VCS(th)/[(VCTRL−0.5)*(1.5/4.0)*VMULT], VCS(th) is the CS pin voltage threshold at which DRV pin goes low (end of

on−time). Koffset is set to zero in test mode, otherwise the formula is more complex.

NCL2801

www.onsemi.com

VREGUL

SOFTOVP

STOP

STATICOVP

OVERSTRESS

OCP

FASTOVP

VREF,VCC

VREF

VREF,XXXX

VDD

THERMAL

SHUTDOWN

TSD

UVP

OFF

STATICOVP

OFF

VREF FB

OTA

SOURCING

UVLO

VCC

Output

Buffer

CLK

All RS latches are

reset dominat

CLK & DT

MANAGMENT

CLK

FFTH

VREGUL

DRV

ZCD

OVERSTRESS

PFCOK

UVLO

ON TIME

MANAGMENT

DRV

Vton

Processing

Circuitry

VCC

ZCD

DRV

ZERO

CROSSING

DETECTION

FAULT

MANAGMENT

DRV CURRENT

SENSE

OVERSTRESS

OCP

VREF,OVS

VREF,OCP

VCTRL

MANAGMENT

VREGUL

STATICOVP

OFF FB

MANAGMENT VREF,DRE

VREF,FAST_OVP

VREF,SOFT_OVP

VREF,UVP

PFCOK

FASTOVP

SOFTOVP

UVP

DRE

ISENSE

MULT

TONMX

ISENSE

VTON

MULT

FFTH

SENSE

FFTH

RST

BONOK

VREF,LLINE

VREF,BONOK

LINE& BO

MANAGMENT

BONOK

LLINE

PFCOK

SOURCING

OFF

BONOK

Figure 2. NCL2801 Block Diagram (SOURCING Flag is High When OTA Sources

Current, if Sourcing Less Than 1nA SOURCING Flag Goes Low)

NCL2801

www.onsemi.com

DETAILED OPERATING DESCRIPTION

Introduction

NCL2801 is designed for working with LED Lighting

applications coping with high ripple voltage on bulk

capacitor and providing optimized line current THD and

good efficiency. In addition, it incorporates protection

features for robust operation. More generally, NCL2801 is

ideal in systems where cost−effectiveness, reliability, low

line current THD, low stand−by power and high efficiency

are key requirements:

•Valley Count Frequency Fold−back: NCL2801 is

designed to drive PFC boost stages in so−called Valley

Count Frequency Fold−back (VCFF). In high load

current condition, the circuit classically operates in

Critical conduction Mode (CrM) also called 1st valley

switching. When output power is decreasing, if a

threshold is reached (determined by sensing the CS pin

impedance during initial power up), a dead time based

on a number of valleys is added. The number of valleys

will increase, each time a dead time window (based on

VCTRL value) is entered. By construction, this counting

process will avoid valley hoping during the mains

voltage period. If the output power continues

decreasing and the 6th valley is reached, extra “analog”

dead time will be added based on a voltage ramp (see

Figure 4). On−time will be synchronized with a valley.

A timer will clamp the total switching period to not

exceed 36.5 ms (the switching frequency will never go

under about 27.4 kHz). The switching frequency

depends on output voltage, input voltage, and boost

inductor value, and increases as the load power

increases. Hysteresis and added to the VCTRL control

windows to avoid valley hopping during steady state

conditions. VCFF maximizes the efficiency at both

nominal and light load. Similarly to FCCrM

controllers, an internal circuitry allows near−unity

power factor even when the switching frequency is

reduced.

•Low Start−up Current: The start−up consumption of the

circuit is minimized to allow the use of high impedance

start−up resistors to precharge the VCC capacitor. Also,

the minimum value of the UVLO hysteresis is 6 V to

avoid the need for large VCC capacitors and help

shorten the start−up time without the need for excessive

dissipation in the start−up circuit. The [*C*] & [*D*]

version is preferred in applications where the circuit is

fed by an external power source (from an auxiliary

power supply or from a downstream converter). After

start−up, the high VCC maximum rating allows a large

operating range from 10.5 V up to 27 V.

•Fast Line / Load Transient Compensation (Dynamic

Response Enhancer): Since PFC stages exhibit low loop

bandwidth, abrupt changes in the load or input voltage

(e.g. at start−up) may cause excessive over or

under−shoot. This circuit limits possible deviations

from the regulation level as follows:

−NCL2801 linearly decays the power delivery to zero

when the output voltage exceeds the soft OVP limit

(105% of VREF) for option [C**]). Soft OVP feature

is disabled on options [A**] &[B**]. If this soft

OVP is too smooth and the output continues to rise,

the circuit immediately (priority to Fast OVP)

interrupts the power delivery when the output

voltage is 112.5 % above its desired level (Fast

OVP) for options [A**]. Options [B**] & [C**] are

providing lower Fast OVP thresholds. Fast OVP

threshold is higher than Soft OVP threshold for

option [C**].

−While disabled on options [*A*], [*C*] and [*E*]

after startup time, NCL2801 has a DRE (Dynamic

Response Enhancer) circuitry on options [*B*],

[*D*]&[*F*] which dramatically speeds−up the

regulation loop when the output voltage goes below

95.5 % of its regulation level. The DRE function is

enabled only after the PFC stage has started−up to

allow normal soft−start operation to occur. For all

the product options, the DRE is active during the

start−up phase to accelerate the start−up (VCTRL

pin voltage is brought at its higher value by the by

half of the 200−mA DRE current source which

charges the capacitors of the compensation network)

•Soft−OVP / Fast−OVP ( Over Voltage Protection)

There are cases (for example during an high−load to

low−load rapid transition) were the bulk capacitor

voltage goes up very rapidly above the voltage

regulation level triggering Over−Voltage protection.

When the bulk capacitor voltage Vbulk reaches typically

105% of its nominal value, the Soft−OVP protection is

triggered, causing the duty−ratio to decrease gradually

down to zero. As a consequence, Vbulk decreases and

when Vbulk reaches the low level of Soft−OVP

threshold (typically 103% of nominal Vbulk) the

protection is released and the voltage regulation loop

takes−over .If Vbulk rises faster and reaches the

Fast−OVP threshold (typically 107% of nominal

Vbulk), the switching is instantaneously stop (DRV

signal is disabled). As a consequence, Vbulk decreases

and when the low level of Fast−OVP threshold is

reached (typically 103% of nominal Vbulk) the

protection is released and the voltage regulation loop

takes−over. Soft−OVP has only one level and can be

disabled dependent on product option. Three Fast_OVP

levels are available by product options : typically 107,

110 and 112% of nominal Vbulk. The 112% option is

well suited for applications using a low value bulk

capacitor were the two−times mains frequency Vbulk

NCL2801

www.onsemi.com

ripple voltage is high (in this case Soft−OVP is

disabled)

•Safety Protections: Permanently monitoring the input

and output voltages, the MOSFET current and the die

temperature to protect the system from possible

over−stress makes the PFC stage extremely robust and

reliable. In addition to the OVP protection, the

following methods of protection are provided :

−Maximum Current Limit: The circuit senses the

MOSFET current and turns off the power switch if

the set current limit is exceeded. In addition, the

circuit enters a low duty−cycle operation mode when

the current reaches 150% of the current limit as a

result of the inductor saturation or a short of the

bypass diode.

−Thermal Shutdown: An internal thermal circuitry

disables the gate drive when the junction

temperature exceeds 150°C (typically). The circuit

resumes operation once the temperature drops below

approximately 100°C (50°C hysteresis).

•Output Stage Totem Pole: NCL2801 incorporates a −0.5

A / +0.8 A gate driver to efficiently drive most TO220

or TO247 power MOSFETs.

NCL2801 Operation Modes

As mentioned, NCL2801 PFC controller implements a

Valley Count Frequency Fold−back (VCFF) where:

−The circuit operates in classical Critical conduction

Mode (CrM) when output power is high and VCTRL

pin voltage greater than a threshold (VCTRL,th,12 for

VCTRL decreasing and VCTRL,th,21 for VCTRL

increasing) which value is determined by the value the

resistance RCS placed between CS pin and top of

Rsense which bottom is connected to GND (Rsense

being negligible versus RCS, it is the RCS value which

is sensed). RCS value is sensed just before the startup

phase (see Table 6).

−When the output power decreases the NCL2801

reduces the operating frequency by means of increasing

valley number count up to 6 valleys (the number of

valleys between end of inductor demagnetization and

power MOSFET turn−on determines the dead time

value). After counting is done, the power MOSFET

turns on at drain voltage valley. When 6th valley is

reached and VCTRL voltage stays under 0.77 V, an extra

“analog” dead time is added based on a voltage ramp

(see Figure 4). The added analog dead time tADT is

based on 0.77 V minus VCTRL value. tADT will be equal

to zero when (0.5 V−VCTRL) = 0 V and will increase

monotonically versus VCTRL decreases while VCTRL is

under the 0.77 V threshold corresponding to

VCTRL,th,56. The analog dead time added tADT will

equal typically 20 ms when VCTRL=0.5 V.

− When additional “analog” dead time is added, the

power MOSFET turn−on will, by default, be

synchronized with the falling edge of ZCD signal

(valley turn−on) and there will be possible, upon

request, of no valley synchronization for the on−time

start. The total dead−time (number of valleys and extra

dead−time) will not exceed 36.5 ms (A timer will be

clamping the dead time).

−When the output power increases, the extra ”analog”

dead−time plus number of valleys dead time will

decrease ,according in which VCTRL pin voltage

window VCTRL pin voltage is, down to 1st valley

switching which is the CrM mode. The VCTRL pin

voltage window in which VCTRL pin voltage is will be

detected with comparators having an hysteresis to avoid

valley hopping due to VCTRL pin voltage ripple.

−It will be the responsibility of the application designer

not to allow a VCTRL pin voltage ripple (at 2 times the

mains frequency) greater than the hysteresis of VCTRL

windows.

−Valley hopping can lead to audible noise. The

NCL2801 avoids this activity by locking the operating

valley before turning on the MOSFET during steady

state operation.

NCL2801

www.onsemi.com

High Load Current

One valley (CrM)

Low Load Current

More valleys (DCM)

Counting 1 valley

Counting 3 valleys

Lower Load Current

More valleys (DCM)

Counting 6 valleys

Extremely Low Load Current

More valleys (DCM)

Plus analog dead time

Counting 6 valleys + tADT

tADT

Figure 3. Valley Switching Operation in CrM and DCM Modes Seen Through Power MOSFET

Drain Voltage

As illustrated in Figure 3, under high load conditions, the

boost stage is operating in CrM (only one valley is counted

before turning on the power MOSFET). The second

example shows a DCM state of operation where 3 valleys

have been counted before turning on the power MOSFET.

The third example shows a DCM state with lower output

power than the previous one where 5 valleys have been

counted before turning on the power MOSFET.The fourth

example shows how additional dead time is added after 6th

valley.

Valley Count Frequency Foldback (VCFF)

The turn−on of the power MOSFET is synchronized with

the valley of the power MOSFET drain voltage signal by the

means of counting the falling edges of the ZCD signal until

the counter reaches the number of valleys set by the window

in which the VCTRL pin voltage is (see Figure 4). The 3−bit

counter allows to work “Valley synchronized” up to 6

valleys. When the 6th valley is reached, and VCTRL is lower

than 0.770 V (VCTRL,th,56 = 0.770 V whatever frequency

foldback threshold setting), an additional analog dead time

will be added to the 6 valleys dead time and there will be

valley synchronization turn−on of the power MOSFET

(ADT_nosync = 0 by default) based on falling edge of ZCD

signal. The total dead−time (number of valleys and extra

analog dead−time) will not exceed 36.5 ms. As a result of this

timer the minimum switching frequency will not go under

27.4 kHz.

NCL2801

www.onsemi.com

DIGITAL NBR OF

VALLEYS CODING

ZCD

VCTRL

COUNTER

DRV

RST

DIGITAL

COMPARATOR

CLK

DRV

RST

−us TIMER

CMPOUT

V2I

1/RADT

Rsense

RCS RCS

stored

VCTRL,th,12

VCTRL,th,23

VCTRL,th,34

VCTRL,th,45

VCTRL,th,56

VCTRL,max

VCTRL,th,21

VCTRL,th,32

VCTRL,th,43

VCTRL,th,54

VCTRL,th,65

RCS –V

CTRL,th,ij

Lookup−Table

ADT

IADT

VADT

CADT

ZCDbar

DRV

ADT_nosync

Figure 4. Valley Count Turn−on Block Diagram

36.5

This Valley Counting (VC) method avoids “valley

hoping” during the half period of mains voltage which is on

other designs, the cause of undesired mains current ringing

glitches due to the excitation of the input EMI filter by a dead

time discontinuity. The NCL2801 circuitry acts so that the

PFC controller transitions from the n valley to (n+1) valley

or from the n valley to (n−1) and stays on this valley number

is long as the VCTRL pin voltage stays in a the voltage

window corresponding to this valley number. If no

demagnetization is sensed the power MOSFET will be

turned−on after a watchdog timing of 200−ms.

The system relies on the counting of ZCD pulses to

determine dead−time periods. Should the ZCD pulses

diminish in voltage so that the event timing can’t be used, an

internal copy of the last reliable first−to−second falling edge

timing is substituted for the natural ZCD ring. The substitute

timing for a second falling edge is allowed 1us beyond the

recorded value before being asserted. The substitute timing

for the third falling edge and afterward is allowed 250 ns

beyond the recorded value before a ZCD pulse is asserted.

The NCL2801 PFC controller, depending on the

application power output which is correlated with the

NCL2801

www.onsemi.com

VCTRL pin voltage level, starts adding a dead−time tDT. The

system adjusts the on−time tON (by means of peak current

control) versus tDT (see Figure 5) and consequently the

output power in order to ensure that the instantaneous mains

current remains in phase with the mains instantaneous

voltage (creating a unity PF).

Ipeak ,max

Iind

CLK

tON tDEMAG

Tsw

tDT

time

DRV

Figure 5. NCL2801 Clock, Dead Time and tON waveforms

When the output power is at the maximum available for

a given application and the inductor peak current limitation

is not triggering, VCTRL pin voltage (VCTRL), is above the

frequency foldback threshold (VCTRL,th,21) making the

controller to work in CrM mode. When output power

decreases VCTRL will go under the frequency foldback

threshold (VCTRL,th,12) and DCM mode will be forced by

adding dead time as explained before.

Adding dead−time will naturally decrease the switching

frequency, hence the FF (standing for Frequency Foldback)

which is part of the name VCFF.

The switching frequency in DCM mode is given by the

following equation..

FSW,DCM +1

tDT )tON )tDEMAG

(eq. 1)

The value of the external resistor placed between CS pin

and Rsense will determine the value of the VCTRL pin

voltage frequency foldback threshold.

CrM−DCM Threshold

For a given application, Rsense and Rmult divider ratio of

the resistors bridge connected to MULT pin are set such as

the maximum power is given just under to the maximum

VCTRL pin voltage VCTRL which is 4.5 V. Zero ouput

power will be supplied for VCTRL=0.5 V

For adjusting at which VCTRL value the transition from

CrM to DCM mode will happen, the resistance value

between CS pin and GND will be sensed before start−up and

its value stored digitally (see Figure 6). The sensed

resistance is equal to RCS plus Rsense, but because Rsense

value is much lower than RCS, it is the RCS value which will

be sensed.

This resistor sense will be done after VCC,on level is

reached and just before the controller starts switching in

order to avoid any noise perturbation the sensing (see Figure

6). The IRCS 1−mA (+/− 4%) current source, active when

RCS flag is high will generate a voltage drop through RCS

(+/−1%) resistor and this voltage drop will be compared to

internal voltage references to identify which is the RCS

resistor value and set the internal frequency foldback

settings.

NCL2801

www.onsemi.com

RCS

RCS óVCTRL ,th,12

Lookup−Table

IRCS

RCS

CLK

RCS

VCC_CMP

VCC_CMP_new

Controller starts

switching

RCS value

is stored

here

(+/−1%)

VRCS,REF ,5

VRCS,REF ,4

VRCS,REF,3

VRCS,REF,2

VRCS,REF,1

Open_RCS

Figure 6. RCS Sensing Method And Schematic

Table 7.

RCS (W)VCTRL,th,12 (V)

1000 2.19

620 1.83

330 1.48

150 1.12

gives the digital code used in Figure 6 corresponding to

the RCS resistor value which in turn will be used to set the

CrM to DCM threshold (when output power is decreasing).

There will be a different DCM to CrM threshold than CrM

to DCM making an hysteresis to avoid valley hopping (see

Table 7 and Figure 4).

During this RCS identification phase which main purpose

is to setting the the frequency foldback thresholds and

number of valley for dead time, if it happen that VCS voltage

is greater than VRCS,REF,5 an OPEN CS pin fault will be

triggered and latched disabling the startup of the controller,

the fault will be released if VCC pin voltage falls unders

VCC,rst. On the other hand if it happen that VCS voltage is

lower than VRCS,REF,1 a SHORT CS pin fault will be

triggered and latched disabling the startup of the controller,

the fault will be released if VCC pin voltage falls unders

VCC,rst.

DCMn−DCMn+1 and DCMn+1−DCMn Transition

Hysteresis

As explained before, DCM mode is driven by the number

of valleys counted before the power MOSFET turns on.

As shown in Figure 7, the forced number of valleys,

shown in the Y−axis, depends on 5 VCTRL pin voltage

windows,

the X−Axis representing the VCTRL pin voltage. In order

to avoid valley hopping due to VCTRL pin voltage ripple,

we have included an hysteresis. We can clearly see in Figure

NCL2801

www.onsemi.com

7 that the VCTRL hysteresis voltage is defined by: VCTRL,hyst

= VCTRL,th43 − VCTRL,th,34 and more generally by VCTRL,hyst

= VCTRL,th,ij − VCTRL,th,ji. If VCTRL pin peak−to−peak

ripple voltage stays under VCTRL,hyst there will be no valley

hopping.

VCTRL,hyst can be calculated for each frequency foldback

option determined by RCS value from the thresholds

specified in Table 7. While the hysteresis between two

adjacent valley numbers is constant for one frequency

foldback option, it decreases for options having a lower

CrM to DCM VCTRL threshold. This should not be a

problem as the two times mains frequency ripple also

decreases when VCTRL pin voltage decreases which

results from output power decrease. We can also mention

looking at Figure 7 and the specified frequency foldback

thresholds of Table 7 that VCTRL,th,56 which is the VCTRL

threshold at which we force counting 6 valleys, has always

the same value. This threshold is also called VCTRL,ADT

because when VCTRL pin voltage falls under this threshold,

an analog dead−time starts to be added to the dead−time

determined by counting 6 valleys. The lower VCTRL pin

voltage goes under VCTRL,ADT threshold, the more analog

dead time is added. An example on how the analog dead time

can be added is shown in the circuit of Figure 4 and the

correspond power MOSFET drain voltage is shown in

Figure 3.

NCL2801

www.onsemi.com

Entering Forced Valley #

Exiting Forced Valley #

VCTRL (V)

Forced Valley #

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

VCTRL (V)

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

@RCS = 1000 W

@RCS = 330 W

VCTRL ,ADT

Forced Valley #

VCTRL,th,56

VCTRL,th,65

VCTRL,th,45

VCTRL,th,12

VCTRL,th,34

VCTRL,th,23

VCTRL ,th,54

VCTRL ,th,43

VCTRL,th,32

VCTRL,hyst

VCTRL,th,56

VCTRL,th,65

VCTRL,th,45

VCTRL,th,12

VCTRL,th,34

VCTRL,th,23

VCTRL ,th,54

VCTRL ,th,43

VCTRL,th,32

VCTRL ,th,21

VCTRL,hyst

VCTRL,th,21

Figure 7. Forced Valley Number versus VCTRL Pin Voltage For a Two Different RCS

Values of the Mandatory List {150 W, 330 W, 620 W, 1000 W}

NCL2801

www.onsemi.com

NCL2801 On−time Modulation and VTON Processing

Circuit

Let’s analyze the ac line current absorbed by the PFC

boost stage. The initial inductor current at the beginning of

each switching cycle is always zero. The coil current ramps

up when the MOSFET is on. The slope is (Vin/L) where L is

the coil inductance. At the end of the on−time (t1), the

inductor starts to demagnetize. The inductor current ramps

down until it reaches zero. The duration of this phase is (t2).

In some cases, the system enters then the dead−time (t3) that

lasts until the next clock is generated.

One can show that the ac line current is given by:

Iin +Vin

t1(t1)t2)

2TL

(eq. 2)

Where

T+t1)t2)t3(eq. 3)

is the switching period and V

in is the ac line rectified

voltage.

In light of this equation, we immediately note that Iin is

proportional to V

in if [t1.(t1+t2)/T] is a constant.

Ipeak,max

Iind t1t2

Vin

time

L1 D1

Vin Vout

Iind

Cbulk

Cin

DRV

Rsense

time

Figure 8. PFC boost converter and Inductor Current in DCM

NCL2801 operates in current control mode. As portrayed

by Figure 8 & Figure 10, the MOSFET on−time t1 results

from a current control mode circuitry which is using a

dedicated circuitry monitoring Vctrl and dead−time t3

ensuring [t1.(t1+t2)/T] is constant and as a result making Iin

proportional to V

in (PF=1)

On−time t1, also called tON, has a high value clamp called

tON,max, generated by an internal circuitry. This 30−ms

clamp value is given for maximum VCTRL pin voltage

(VCTRL=4.5 V) but reduces down to 5 ms when VCTRL pin

voltage reaches 0.5 V which is its minimum value.

The input current is then proportional to the input voltage.

Hence, the ac line current is properly shaped.

One can note that this analysis is also valid in the CrM

case. This condition is just a particular case of this

functioning where (t3=0), which leads to (t1+t2=T) and

(Vton=Vregul). That is why the NCL2801 automatically

adapts to the conditions and transitions from DCMn to

DCMn+1 and DCMn+1 to DCMn without power factor

degradation and without discontinuity in the power delivery.

This analysis while carried−out for constant on−time

architecture is also valid for the current control architecture

of the NCL2801 because at steady state, what results from

a current control is a constant on−time.

Current Control Mode & THD Enhancer

In order for the mains current to have very good THD, the

Current Control Mode depicted in Figure 10 mode is

preferred.

To improve the mains current THD, an offset voltage is

added to the multiplier output (see Figure 9).

The added offset is equal to Koffset.Vton

The role of this offset is to add on−time and this added

on−time will be very beneficial close to line zero crossing

where, without this offset, the inductor peak current is low

and comparable to the inductor negative peak current

resulting to zero line current. Adding this offset greatly

reduces the time width during which the line current is equal

to zero (line voltage cross−over distortion) and by doing

improve the line current THD.

A traditional scheme, where the inductor current during

on−time multiplied by Rsense is compared to a scaled down

rectified mains voltage Vin multiplied by Vton is used. What

may sound strange is the Vton, but Vton is equal to Vregul

when in CrM.

NCL2801

www.onsemi.com

PWM

Rsense

Iind

Vton

Vin

Rmult2

Rmult1

RCS

End of on−time

when high

Vton

Vipeak

Figure 9. Simplified Current Control Circuit (Max On−Time and Blanking Not Shown)

Vregul +(VVCTRL *0.5V) 1.5V

4.0V (eq. 4)

The range of Vregul is equal to 1.5 V and Vregul operates

between 0 V and 1.5 V.

The range of VCTRL is equal to 4.0 V and VCTRL operates

between 0.5 V and 4.5 V.

In DCM mode, the Vton input of the multiplier is modified

thanks to the Vton processing block in order to maintain the

mains current proportional to the mains voltage.

It can be demonstrated that the maximum peak inductor

current is given by the following equation

Iind,peak,max +

Vipeak,max

Rsense +

ǒKmKmult 2

ǸVmains,rms )KoffsetǓ@VTON

Rsense

(eq. 5)

From Iind,peak,max, assuming we are in CrM we can get the

rms line current by :

Imains,rms +

Vind,peak,max

Ǹ+

ǒKmKmult 2

ǸVmains,rms )KoffsetǓ@VTON

ǸRsense

(eq. 6)

Then,

Pmains,rms +

(KmKmult 2

ǸV2mains,rms )KoffsetVmains,rms) @VTON

ǸRsense

(eq. 7)

To better see the effect of Koffset on Pmains,rms the previous

equation can be re−written as follows

Pmains,rms +

KmKmultV2mains,rmsVTON

2Rsense )

KoffsetVmains,rmsVTON

ǸRsense

(eq. 8)

In both previous equations Kmult is the multiplier gain

and Km is given by the following:

Km+

Rmult2

Rmult1 )Rmult2

(eq. 9)

It is important to mention that in CrM mode so particularly

at max output power, VTON=Vregul.

The multiplier gain, for product options having no line

level detection ([**B]&[**D] has a value which does not

vary versus Vmains value.

For product options having line level detection

([**A]&[**C], the multiplier gain has an High Line value

(Kmult,HL) and a Low Line value (Kmult,LL). These two line

NCL2801

www.onsemi.com

level dependent multiplier gain values act as a two−level line

feed forward.

NCL2801 Maximum on−time

In order to avoid the on−time to go too high close to line

voltage zero crossing, a VCTRL dependent maximum on

time circuitry has been added. The on−time limiting values

are linearly depending on VCTRL pin voltage as follows:

30−ms @VCTRL = 4.5 V and 5−ms @VCTRL = 0.55 V

NCL2801 Regulation Block and Output Voltage Control

A trans−conductance error amplifier (OTA) with access to

its inverting input (FB pin) and to its output pin (VCTRL

pin) is provided. It features a typical trans−conductance gain

of 200 mS and a maximum current capability of +/−20 mA.

The output voltage of the PFC stage is typically scaled down

by a resistors divider and monitored by the OTA inverting

input (pin FB). Bias current is minimized (less than 500 nA)

to allow the use of a high impedance feed−back network.

However, it is high enough so that the pin remains in low

state if the pin is not connected.

The output of the error amplifier is brought to pin VCTRL

for external loop compensation. Typically a type−2 network

is applied between pin VCTRL and ground, to set the

regulation bandwidth below about 20 Hz and to provide a

decent phase boost.

The swing of the error amplifier output is limited within

an operating range:

−It is forced above a voltage drop (VF) by a dedicated

circuitry.

−It is clamped not to exceed 4.0 V + the same VF voltage

drop.

The VF value is 0.5 V typically.

The regulated output voltage Vbulk uses an internal

reference voltage VREF = 2.5 V.

The regulated Vbulk voltage (its average value in case of

important ripple) will be equal to VREF multiplied by the

dividing factor given by the resistor bridge placed between

Vbulk and FB pin, resulting for example in Vbulk = 395 V.

Given the low bandwidth of the regulation loop, abrupt

variations of the load, may result in excessive over or

under−shoot. Over−shoot is limited by the Over−Voltage

Protection (OVP) connected to FB pin (Feedback).

Optionally, NCL2801 embeds a “Dynamic Response

Enhancer” circuitry (DRE) that limits under−shoots. The

DRE works during startup phase by injecting current into the

VCTRL pin which rises VCTRL pin voltage and allows

more current to charge the bulk capacitor. After the startup

phase, when internal PFCOK flag goes high, the DRE is

disabled on some options, but is enabled in other product

options. For the product options where the DRE is enabled,

an internal comparator monitors the FB pin voltage (VFB)

and when VFB is lower than 95.5% of its nominal value, it

connects the 220−mA current source to VCTRL pin in order

to speed−up the charge of the compensation network.

Effectively this appears as a 10x increase in the loop gain.

The circuit also detects overshoot using the Soft OVP

circuitry and immediately reduces the power delivery when

the output voltage exceeds a value which is product option

dependent.

The error Operational Transconductance Amplifier OTA

and the OVP and DRE comparators share the same input

information. Based on the typical value of their parameters

and if Vbulk,nom is the bulk nominal voltage value (e.g., 400

V), we can deduce:

•Output Regulation Level: Vbulk,nom

•Output DRE Level: Vbulk,dre =

95.5%.Vbulk,nom

•Output Soft OVP Level: Vbulk,sovp =

X%.Vbulk,nom

•Output Fast OVP level: Vbulk,fovp =

Y%.Vbulk,nom

NOTE: Note: X% and Y% are product option dependent

Current Sense and Current Control

The power MOSFET current Iind is sensed during the

on−time phase by the resistor Rsense inserted between the

MOSFET source and ground (see Figure 10). The voltage

Rsense.Iind after a proper leading edge blanking (tLEB,OCP

and tLEB,OVS) starting from the power MOSFET rising

edge drive signal (DRV) is compared to internal

over−current protection (OCP) and overstress protection

(OVS) internal references (namely VCS(th) and

VCS,OVS(th)) which when triggered ends the on−time for

OCP or stops the switching during 800 us for OVS. The

voltage Rsense.Iind is also low−pass filtered (R=20 kW,

C=20 pF see Figure 10), leading edge blanked and

compared to the multiplier output voltage to generate the

end of the on−time which is typical of a current mode control

(see Figure 10).

In order to improve the THD of the mains current, a Vton

dependent offset at the output of the multiplier and a

TONMAX processing block have been added (see Figure

10).

Vton is one of the inputs of the multiplier for helping

improve THD in DCM mode (Frequency Foldback).

Vton is equal to Vregul which is proportional to the

VCTRL pin voltage when in CrM mode.

NCL2801

www.onsemi.com

PWM

Rsense

Iind

Vton

Vin

Rmult2

Rmult1

Vregul

RCS

RCS – VCRTL,th,ij,Rcs

Lookup−Table

VCTRL,th,12,Rcs controls

the Frequency Foldback

threshold

End of on−time

when high

OCP

OVS

20kOhms

10pF

BLK

Figure 10. PWM Circuit Showing Current Control Mode With a New MULT Pin

Vton

Koffset.

Zero Current Detection (ZCD)

The ZCD pin features a classical and robust ZCD

detection based on sensing the auxiliary winding voltage as

shown in Figure 11. The ZCD pin voltage is clamped high

at VCC plus a diode Vf (0.7 V) and clamped low at minus

a diode Vf (−0.7 V) and then compared to ZCD thresholds

voltages VZCD,th,H and VZCD,th,L (see Table 6).

When no signal is received that triggers the ZCD

comparator to indicate the end of inductor demagnetization,

an internal 200−ms watchdog timer initiates the next drive

pulse.

NCL2801

www.onsemi.com

ZCD

RZCD

Vaux

VZCD,th,H

VZCD ,th,L

VCC

Figure 11. Zero Current Detection (ZCD) Circuitry

Brown−Out Detection) – (Options [**A], [**B])

Thanks to the line voltage scaled−down by Km and

rectified available on MULT−pin (Vm) a Brown−Out feature

is available on options [**A], [**B].

Vm(t) +Km@Vin(t) (eq. 10)

With

Km+

Rmult2

Rmult1 )Rmult2

(eq. 11)

The VMULT voltage is sensed and when eventually VMULT

falls under Brown−out internal reference voltage VBOL for

50 ms, BONOK flag will be set to 1. After BONOK flag is

set to 1, drive is not disabled, instead, a 30−mA current

source (IVCTRL(BO)) is applied to VCTRL pin to gradually

reduce VCTRL. As a result, the circuit only stops pulsing

when the STATICOVP function is activated. At that

moment, the circuit stops switching. This method limits any

risk of false triggering.

The input of the PFC stage has some impedance that leads

to some sag of the input voltage when the input current is

large. If the PFC stage suddenly stops while a high current

is drawn from the mains, the abrupt decay of the current may

make the input voltage rise and the circuit detect a correct

line level. Instead, the gradual decrease of VCTRL avoids a

line current discontinuity and limits the risk of false

triggering.

The line voltage (Vline,BO,H) at which the controller starts

switching which can be called brown−in and is given by the

following equation:

Vline,BO,H +Vline,Brown*in +

VBOH

Km2

Ǹ(eq. 12)

The line voltage (Vline,BO,L) at which the controller starts

reducing on−time until it stops switching which can be

called brown−out and is given by:

Vline,BO,L +Vline,Brown*in +

VBOL

Km2

Ǹ(eq. 13)

It has to be reminded that while changing Km by changing

the Rmult resistors dividing ratio can help to shift up or

down the line brown−in and brown−out levels, Km

determines also the internal gain of the controller, together

with Rsense and Kmult (multiplier gain), so care must be

taken at adjusting Rsense accordingly to the Km adjustment.

Line Level Detection and 2−Level Line Feed−Forward–

(Options [**A], [**C])

For product options [**A], [**C], the line level detection

(High Line or Low Line) feature together with a two−level

line feed forward is activated and operates as described here

after.

MULT pin voltage VMULT is used to sense the line voltage

and apply a two−level line feed−forward.

The VMULT voltage is compared to a VHL internal voltage

reference. If VMULT exceeds VHL, the circuit detects

a High−Line state (LLINE flag is set to 0) and the multiplier

gain is set to value corresponding to High Line which is

Kmult,HL. Once this occurs, if VMULT remains below VLL

for 25 ms, the circuit detects a Low−Line state (VHL(hyst)

hysteresis) and the multiplier gain is set to Kmult,LL.

At startup, the circuit is in High−Line state (LLINE flag

is set to 0) and then VMULT will be used to determine the

High−Line or Low−Line state.

NCL2801

www.onsemi.com

The line range detection circuit allows more optimal loop

gain control for universal (wide input mains) applications by

adjusting the multiplier gain value versus line voltage status

(High Line or Low Line).

For the options [**B], [**D], no line feedforward action

is taken based on the line level and the multiplier gain

remains set at Kmult whatevever line level.

The High Line and Low Line thresholds, respectively

Vline,HL and Vline,LL are given by the following equations:

Vline,HL,rms +

VHL

Km2

Ǹ(eq. 14)

Vline,LL,rms +

VLL

Km2

Ǹ(eq. 15)

VREF,LLINE

VREF,BONOK

VHL if LLINE=1

VLL otherwise

VBOH if BONOK=1

VBOL otherwise

Vin

Figure 12. Input Line Sense and Brown−out Monitoring

Thermal Shut−Down (TSD)

An internal circuitry sensing the silicon temperature

disables the circuit gate drive and keeps the power switch off

when the junction temperature exceeds 150_C. The output

stage is then enabled once the temperature drops below

about 100_C (50_C hysteresis).

The temperature shutdown remains active as long as the

circuit is not reset, that is, as long as VCC is higher than a reset

threshold.

Output Drive Section

The output stage contains a totem pole optimized to

minimize the cross conduction current during high

frequency operation. Its high current capability

(−500 mA/+800 mA) allows it to effectively drive high gate

charge power MOSFET.

OFF Mode

As previously mentioned, the circuit turns off when one

of the following faults is detected:

•Incorrect feeding of the circuit (“UVLO” high when

VCC<VCC(off), VCC(off)).

•Excessive die temperature detected by the thermal

shutdown

•STATICOVP (see Figure 2)

Generally speaking, the circuit turns off when the

conditions are not proper for desired operation. In this mode,

the controller stops operating. The major part of the circuit

sleeps and its consumption is minimized.

More specifically, when the circuit is in OFF state:

−The drive output is kept low

−All the blocks are off except:

♦The UVLO circuitry that keeps monitoring the

VCC voltage and controlling the start−up current

source accordingly.

♦The TSD (thermal shutdown)

−Vctrl is grounded so that when the fault is removed, the

device starts−up under the soft start mode.

−The internal “PFCOK” signal is grounded.

−The output of the “Vton processing block” is grounded

Failure detection

When manufacturing a power supply, elements can be

accidently shorted or improperly soldered. Such failures can

also happen to occur later on because of the components

fatigue or excessive stress, soldering defaults or external

interactions. In particular, adjacent pins of controllers can be

shorted; a pin can be grounded or badly connected. Such

open/short situations are generally required not to cause fire,

smoke or hazardous conditions. NCL2801 integrate

functions that ease meeting this requirement. Among them,

we can list:

♦Fault of the GND connection

If the GND pin is not connected, internal circuitry

detects it and if such a fault is detected for 200 ms,

the circuit stops operating.

♦Fault of the FB connection

If the FB pin is left open because for example of bad

NCL2801

www.onsemi.com

soldering, an internal pull down current source pulls

down the FB voltage under the UVP threshold and

the controller is turned off.

♦Detection the ZCD pin improper connection

If the ZCD pin is floating or shorted to GND it is

detected by internal circuitry and the circuit stops

operating.

♦Boost or bypass diode short

The controller addresses the short situations of the boost

and bypass diodes (a bypass diode is generally placed

between the input and output high−voltage rails to divert this

inrush current). Practically, the overstress protection is

implemented to detect such conditions and forces a low

duty−cycle operation until the fault is gone.

Table 8. NCL2801 ORDERING TABLE

Ordering Part No.

Soft

OVP

Fast

OVP (%)

VCC Start

(V)

DRE

(after

start)

DRE

(during

start)

Brown

Out

Line

Range

Detect Package Shipping

NCL2801CDADR2G X 107 12.5 X X X X

SOIC−8

(Pb−Free)

2500/Tape

& Reel

NCL2801CDBDR2G X 107 12.5 X X X

NCL2801CFADR2G X 107 10.5 X X X X

SOIC−8 NB

CASE 751−07

ISSUE AK

DATE 16 FEB 2011

SEATING

PLANE

X 45 _

NOTES:

1. DIMENSIONING AND TOLERANCING PER

ANSI Y14.5M, 1982.

2. CONTROLLING DIMENSION: MILLIMETER.

3. DIMENSION A AND B DO NOT INCLUDE

MOLD PROTRUSION.

4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)

PER SIDE.

5. DIMENSION D DOES NOT INCLUDE DAMBAR

PROTRUSION. ALLOWABLE DAMBAR

PROTRUSION SHALL BE 0.127 (0.005) TOTAL

IN EXCESS OF THE D DIMENSION AT

MAXIMUM MATERIAL CONDITION.

6. 751−01 THRU 751−06 ARE OBSOLETE. NEW

STANDARD IS 751−07.

0.10 (0.004)

SCALE 1:1

STYLES ON PAGE 2

DIM

MIN MAX MIN MAX

INCHES

4.80 5.00 0.189 0.197

MILLIMETERS

B3.80 4.00 0.150 0.157

C1.35 1.75 0.053 0.069

D0.33 0.51 0.013 0.020

G1.27 BSC 0.050 BSC

H0.10 0.25 0.004 0.010

J0.19 0.25 0.007 0.010

K0.40 1.27 0.016 0.050

M0 8 0 8

N0.25 0.50 0.010 0.020

S5.80 6.20 0.228 0.244

−X−

−Y−

0.25 (0.010)

−Z−

0.25 (0.010) ZSXS

____

XXXXX = Specific Device Code

A = Assembly Location

L = Wafer Lot

Y = Year

W = Work Week

G= Pb−Free Package

GENERIC

MARKING DIAGRAM*

XXXXX

ALYWX

IC Discrete

XXXXXX

AYWW

1.52

0.060

7.0

0.275

0.6

0.024

1.270

0.050

4.0

0.155

ǒmm

inchesǓ

SCALE 6:1

*For additional information on our Pb−Free strategy and soldering

details, please download the ON Semiconductor Soldering and

Mounting Techniques Reference Manual, SOLDERRM/D.

SOLDERING FOOTPRINT*

Discrete

XXXXXX

AYWW

(Pb−Free)

XXXXX

ALYWX

(Pb−Free)

XXXXXX = Specific Device Code

A = Assembly Location

Y = Year

WW = Work Week

G= Pb−Free Package

*This information is generic. Please refer to

device data sheet for actual part marking.

Pb−Free indicator, “G” or microdot “G”, may

or may not be present. Some products may

not follow the Generic Marking.

MECHANICAL CASE OUTLINE

PACKAGE DIMENSIONS

ON Semiconductor and are trademarks of Semiconductor Components Industries, LLC dba ON Semiconductor or its subsidiaries in the United States and/or other countries.

ON Semiconductor reserves the right to make changes without further notice to any products herein. ON Semiconductor makes no warranty, representation or guarantee regarding

the suitability of its products for any particular purpose, nor does ON Semiconductor assume any liability arising out of the application or use of any product or circuit, and specifically

disclaims any and all liability, including without limitation special, consequential or incidental damages. ON Semiconductor does not convey any license under its patent rights nor the

rights of others.

98ASB42564B

DOCUMENT NUMBER:

DESCRIPTION:

Electronic versions are uncontrolled except when accessed directly from the Document Repository.

Printed versions are uncontrolled except when stamped “CONTROLLED COPY” in red.

PAGE 1 OF 2

SOIC−8 NB

CASE 751−07

ISSUE AK

DATE 16 FEB 2011

STYLE 4:

PIN 1. ANODE

2. ANODE

3. ANODE

4. ANODE

5. ANODE

6. ANODE

7. ANODE

8. COMMON CATHODE

STYLE 1:

PIN 1. EMITTER

2. COLLECTOR

3. COLLECTOR

4. EMITTER

5. EMITTER

6. BASE

7. BASE

8. EMITTER

STYLE 2:

PIN 1. COLLECTOR, DIE, #1

2. COLLECTOR, #1

3. COLLECTOR, #2

4. COLLECTOR, #2

5. BASE, #2

6. EMITTER, #2

7. BASE, #1

8. EMITTER, #1

STYLE 3:

PIN 1. DRAIN, DIE #1

2. DRAIN, #1

3. DRAIN, #2

4. DRAIN, #2

5. GATE, #2

6. SOURCE, #2

7. GATE, #1

8. SOURCE, #1

STYLE 6:

PIN 1. SOURCE

2. DRAIN

3. DRAIN

4. SOURCE

5. SOURCE

6. GATE

7. GATE

8. SOURCE

STYLE 5:

PIN 1. DRAIN

2. DRAIN

3. DRAIN

4. DRAIN

5. GATE

6. GATE

7. SOURCE

8. SOURCE

STYLE 7:

PIN 1. INPUT

2. EXTERNAL BYPASS

3. THIRD STAGE SOURCE

4. GROUND

5. DRAIN

6. GATE 3

7. SECOND STAGE Vd

8. FIRST STAGE Vd

STYLE 8:

PIN 1. COLLECTOR, DIE #1

2. BASE, #1

3. BASE, #2

4. COLLECTOR, #2

5. COLLECTOR, #2

6. EMITTER, #2

7. EMITTER, #1

8. COLLECTOR, #1

STYLE 9:

PIN 1. EMITTER, COMMON

2. COLLECTOR, DIE #1

3. COLLECTOR, DIE #2

4. EMITTER, COMMON

5. EMITTER, COMMON

6. BASE, DIE #2

7. BASE, DIE #1

8. EMITTER, COMMON

STYLE 10:

PIN 1. GROUND

2. BIAS 1

3. OUTPUT

4. GROUND

5. GROUND

6. BIAS 2

7. INPUT

8. GROUND

STYLE 11:

PIN 1. SOURCE 1

2. GATE 1

3. SOURCE 2

4. GATE 2

5. DRAIN 2

6. DRAIN 2

7. DRAIN 1

8. DRAIN 1

STYLE 12:

PIN 1. SOURCE

2. SOURCE

3. SOURCE

4. GATE

5. DRAIN

6. DRAIN

7. DRAIN

8. DRAIN

STYLE 14:

PIN 1. N−SOURCE

2. N−GATE

3. P−SOURCE

4. P−GATE

5. P−DRAIN

6. P−DRAIN

7. N−DRAIN

8. N−DRAIN

STYLE 13:

PIN 1. N.C.

2. SOURCE

3. SOURCE

4. GATE

5. DRAIN

6. DRAIN

7. DRAIN

8. DRAIN

STYLE 15:

PIN 1. ANODE 1

2. ANODE 1

3. ANODE 1

4. ANODE 1

5. CATHODE, COMMON

6. CATHODE, COMMON

7. CATHODE, COMMON

8. CATHODE, COMMON

STYLE 16:

PIN 1. EMITTER, DIE #1

2. BASE, DIE #1

3. EMITTER, DIE #2

4. BASE, DIE #2

5. COLLECTOR, DIE #2

6. COLLECTOR, DIE #2

7. COLLECTOR, DIE #1

8. COLLECTOR, DIE #1

STYLE 17:

PIN 1. VCC

2. V2OUT

3. V1OUT

4. TXE

5. RXE

6. VEE

7. GND

8. ACC

STYLE 18:

PIN 1. ANODE

2. ANODE

3. SOURCE

4. GATE

5. DRAIN

6. DRAIN

7. CATHODE

8. CATHODE

STYLE 19:

PIN 1. SOURCE 1

2. GATE 1

3. SOURCE 2

4. GATE 2

5. DRAIN 2

6. MIRROR 2

7. DRAIN 1

8. MIRROR 1

STYLE 20:

PIN 1. SOURCE (N)

2. GATE (N)

3. SOURCE (P)

4. GATE (P)

5. DRAIN

6. DRAIN

7. DRAIN

8. DRAIN

STYLE 21:

PIN 1. CATHODE 1

2. CATHODE 2

3. CATHODE 3

4. CATHODE 4

5. CATHODE 5

6. COMMON ANODE

7. COMMON ANODE

8. CATHODE 6

STYLE 22:

PIN 1. I/O LINE 1

2. COMMON CATHODE/VCC

3. COMMON CATHODE/VCC

4. I/O LINE 3

5. COMMON ANODE/GND

6. I/O LINE 4

7. I/O LINE 5

8. COMMON ANODE/GND

STYLE 23:

PIN 1. LINE 1 IN

2. COMMON ANODE/GND

3. COMMON ANODE/GND

4. LINE 2 IN

5. LINE 2 OUT

6. COMMON ANODE/GND

7. COMMON ANODE/GND

8. LINE 1 OUT

STYLE 24:

PIN 1. BASE

2. EMITTER

3. COLLECTOR/ANODE

4. COLLECTOR/ANODE

5. CATHODE

6. CATHODE

7. COLLECTOR/ANODE

8. COLLECTOR/ANODE

STYLE 25:

PIN 1. VIN

2. N/C

3. REXT

4. GND

5. IOUT

6. IOUT

7. IOUT

8. IOUT

STYLE 26:

PIN 1. GND

2. dv/dt

3. ENABLE

4. ILIMIT

5. SOURCE

6. SOURCE

7. SOURCE

8. VCC

STYLE 27:

PIN 1. ILIMIT

2. OVLO

3. UVLO

4. INPUT+

5. SOURCE

6. SOURCE

7. SOURCE

8. DRAIN

STYLE 28:

PIN 1. SW_TO_GND

2. DASIC_OFF

3. DASIC_SW_DET

4. GND

5. V_MON

6. VBULK

7. VBULK

8. VIN

STYLE 29:

PIN 1. BASE, DIE #1

2. EMITTER, #1

3. BASE, #2

4. EMITTER, #2

5. COLLECTOR, #2

6. COLLECTOR, #2

7. COLLECTOR, #1

8. COLLECTOR, #1

STYLE 30:

PIN 1. DRAIN 1

2. DRAIN 1

3. GATE 2

4. SOURCE 2

5. SOURCE 1/DRAIN 2

6. SOURCE 1/DRAIN 2

7. SOURCE 1/DRAIN 2

8. GATE 1

ON Semiconductor and are trademarks of Semiconductor Components Industries, LLC dba ON Semiconductor or its subsidiaries in the United States and/or other countries.

ON Semiconductor reserves the right to make changes without further notice to any products herein. ON Semiconductor makes no warranty, representation or guarantee regarding

the suitability of its products for any particular purpose, nor does ON Semiconductor assume any liability arising out of the application or use of any product or circuit, and specifically

disclaims any and all liability, including without limitation special, consequential or incidental damages. ON Semiconductor does not convey any license under its patent rights nor the

rights of others.

98ASB42564B

DOCUMENT NUMBER:

DESCRIPTION:

Electronic versions are uncontrolled except when accessed directly from the Document Repository.

Printed versions are uncontrolled except when stamped “CONTROLLED COPY” in red.

PAGE 2 OF 2

SOIC−8 NB

www.onsemi.com

ON Semiconductor and are trademarks of Semiconductor Components Industries, LLC dba ON Semiconductor or its subsidiaries in the United States and/or other countries.

ON Semiconductor owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of ON Semiconductor’s product/patent

coverage may be accessed at www.onsemi.com/site/pdf/Patent−Marking.pdf. ON Semiconductor reserves the right to make changes without further notice to any products herein.

ON Semiconductor makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does ON Semiconductor assume any liability

arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.

Buyer is responsible for its products and applications using ON Semiconductor products, including compliance with all laws, regulations and safety requirements or standards,

regardless of any support or applications information provided by ON Semiconductor. “Typical” parameters which may be provided in ON Semiconductor data sheets and/or

specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer

application by customer’s technical experts. ON Semiconductor does not convey any license under its patent rights nor the rights of others. ON Semiconductor products are not

designed, intended, or authorized for use as a critical component in life support systems or any FDA Class 3 medical devices or medical devices with a same or similar classification

in a foreign jurisdiction or any devices intended for implantation in the human body. Should Buyer purchase or use ON Semiconductor products for any such unintended or unauthorized

application, Buyer shall indemnify and hold ON Semiconductor and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and

expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such

claim alleges that ON Semiconductor was negligent regarding the design or manufacture of the part. ON Semiconductor is an Equal Opportunity/Affirmative Action Employer. This

literature is subject to all applicable copyright laws and is not for resale in any manner.

PUBLICATION ORDERING INFORMATION

TECHNICAL SUPPORT

North American Technical Support:

Voice Mail: 1 800−282−9855 Toll Free USA/Canada

Phone: 011 421 33 790 2910

LITERATURE FULFILLMENT:

Email Requests to: orderlit@onsemi.com

ON Semiconductor Website: www.onsemi.com

Europe, Middle East and Africa Technical Support:

Phone: 00421 33 790 2910

For additional information, please contact your local Sales Representative

◊