LNK364DN-TL - Power Integrations, Inc.

Figure 1. Typical Application with LinkSwitch-XT.

Product Highlights

Optimized for Lowest System Cost

• Proprietary IC trimming and transformer construction

techniques enable Clampless™ designs with LNK362

for lower system cost, component count and higher

efﬁ ciency

• Fully integrated auto-restart for short circuit and

open loop protection

• Self-biased supply – saves transformer auxiliary winding

and associated bias supply components

• Frequency jittering greatly reduces EMI

• Meets HV creepage requirements between DRAIN and

all other pins both on the PCB and at the package

• Lowest component count switcher solution

Features Superior to Linear/RCC

• Accurate hysteretic thermal shutdown protection –

automatic recovery improves ﬁ eld reliability

• Universal input range allows worldwide operation

• Simple ON/OFF control, no loop compensation needed

• Eliminates bias winding – simpler, lower cost

transformer

• Very low component count – higher reliability and single

side printed circuit board

• Auto-restart reduces delivered power by 95% during

short circuit and open loop fault conditions

• High bandwidth provides fast turn-on with no overshoot

and excellent transient load response

EcoSmart®– Extremely Energy-Efﬁ cient

• Easily meets all global energy efﬁ ciency regulations with

no added components

• No-load consumption <300 mW without bias winding at

265 VAC input (<50 mW with bias winding)

• ON/OFF control provides constant efﬁ ciency to very

light loads – ideal for mandatory CEC regulations

Applications

• Chargers/adapters for cell/cordless phones, PDAs, digital

cameras, MP3/portable audio players, and shavers

• Supplies for appliances, industrial systems, and metering

Description

LinkSwitch-XT incorporates a 700 V power MOSFET, oscillator,

simple ON/OFF control scheme, a high-voltage switched current

source, frequency jittering, cycle-by-cycle current limit and

thermal shutdown circuitry onto a monolithic IC. The startup

Table 1. Output Power Table.

Notes:

1. Minimum continuous power in a typical non-ventilated enclosed

adapter measured at 50 °C ambient.

2. Minimum practical continuous power in an open frame design

with adequate heat sinking, measured at 50 °C ambient.

3. Packages: P: DIP-8B, G: SMD-8B, D: SO-8C. Please see Part

Ordering Information.

4. See Key Application Considerations section for complete description

of assumptions.

and operating power are derived directly from the DRAIN

pin, eliminating the need for a bias winding and associated

circuitry.

OUTPUT POWER TABLE(4)

PRODUCT(3)

230 VAC ±15% 85-265 VAC

Adapter(1) Open

Frame(2) Adapter(1) Open

Frame(2)

LNK362P/G/D 2.8 W 2.8 W 2.6 W 2.6 W

LNK363P/G/D 5 W 7.5 W 3.7 W 4.7 W

LNK364P/G/D 5.5 W 9 W 4 W 6 W

Output

Wide Range

HV DC Input LNK362

PI-4086-081005

LinkSwitch-XT

Output

Wide Range

HV DC Input LNK363-364

PI-4061-081005

LinkSwitch-XT

a) Clampless ﬂ yback converter with LNK362

b) Flyback converter with LNK363/4

LNK362-364

LinkSwitch-XT Family

Energy Efﬁ cient, Low Power

Off-Line Switcher IC

November 2008

LNK362-364

2-2

Rev. E 11/08

PI-4232-110205

CLOCK

JITTER

OSCILLATOR

5.8 V

4.8 V

SOURCE

(S)

DCMAX

BYPASS

(BP)

FAULT

PRESENT

VILIMIT

LEADING

EDGE

BLANKING

THERMAL

SHUTDOWN

DRAIN

(D)

REGULATOR

5.8 V

BYPASS PIN

UNDER-VOLTAGE

CURRENT LIMIT

COMPARATOR

FEEDBACK

(FB)

6.3 V

RESET

AUTO-

RESTART

COUNTER

VFB -VTH

CLOCK

Figure 3. Pin Conﬁ guration.

Pin Functional Description

DRAIN (D) Pin:

Power MOSFET drain connection. Provides internal operating

current for both startup and steady-state operation.

BYPASS (BP) Pin:

Connection point for a 0.1 μF external bypass capacitor for the

internally generated 5.8 V supply. If an external bias winding is

used, the current into the BP pin must not exceed 1 mA.

FEEDBACK (FB) Pin:

During normal operation, switching of the power MOSFET is

controlled by this pin. MOSFET switching is disabled when a

current greater than 49 μA is delivered into this pin.

SOURCE (S) Pin:

This pin is the power MOSFET source connection. It is also the

ground reference for the BYPASS and FEEDBACK pins.

PI-3491-120706

3a 3b

FB D

P Package (DIP-8B)

G Package (SMD-8B) D Package (SO-8C)

D S

FB S

Figure 2. Functional Block Diagram.

LNK362-364

2-3

Rev. E 11/08

PI-4047-110205

Time (μs)

100

200

400

500

600

300

VDRAIN

136.5 kHz

127.5 kHz

LinkSwitch-XT

Functional Description

LinkSwitch-XT combines a high-voltage power MOSFET

switch with a power supply controller in one device. Unlike

conventional PWM (pulse width modulator) controllers, a

simple ON/OFF control regulates the output voltage. The

controller consists of an oscillator, feedback (sense and logic)

circuit, 5.8 V regulator, BYPASS pin undervoltage circuit,

over-temperature protection, frequency jittering, current limit

circuit, and leading edge blanking integrated with a 700 V

power MOSFET. The LinkSwitch-XT incorporates additional

circuitry for auto-restart.

Oscillator

The typical oscillator frequency is internally set to an average

of 132 kHz. Two signals are generated from the oscillator: the

maximum duty cycle signal (DCMAX) and the clock signal that

indicates the beginning of each cycle.

The oscillator incorporates circuitry that introduces a small

amount of frequency jitter, typically 9 kHz peak-to-peak,

to minimize EMI emission. The modulation rate of the

frequency jitter is set to 1.5 kHz to optimize EMI reduction

for both average and quasi-peak emissions. The frequency

jitter should be measured with the oscilloscope triggered at

the falling edge of the DRAIN waveform. The waveform in

Figure 4 illustrates the frequency jitter.

Feedback Input Circuit

The feedback input circuit at the FB pin consists of a low

impedance source follower output set at 1.65 V for LNK362

and 1.63 V for LNK363/364. When the current delivered into

this pin exceeds 49 μA, a low logic level (disable) is generated

at the output of the feedback circuit. This output is sampled

at the beginning of each cycle on the rising edge of the clock

signal. If high, the power MOSFET is turned on for that cycle

(enabled), otherwise the power MOSFET remains off (disabled).

Since the sampling is done only at the beginning of each cycle,

subsequent changes in the FB pin voltage or current during the

remainder of the cycle are ignored.

5.8 V Regulator and 6.3 V Shunt Voltage Clamp

The 5.8 V regulator charges the bypass capacitor connected to the

BYPASS pin to 5.8 V by drawing a current from the voltage on

the DRAIN, whenever the MOSFET is off. The BYPASS pin is

the internal supply voltage node. When the MOSFET is on, the

LinkSwitch-XT runs off of the energy stored in the bypass capacitor.

Extremely low power consumption of the internal circuitry allows

the device to operate continuously from the current drawn from

the DRAIN pin. A bypass capacitor value of 0.1 μF is sufﬁ cient

for both high frequency decoupling and energy storage.

In addition, there is a 6.3 V shunt regulator clamping the

BYPASS pin at 6.3 V when current is provided to the BYPASS

pin through an external resistor. This facilitates powering of

the device externally through a bias winding to decrease the

no-load consumption to less than 50 mW.

BYPASS Pin Undervoltage

The BYPASS pin undervoltage circuitry disables the power

MOSFET when the BYPASS pin voltage drops below 4.8 V.

Once the BYPASS pin voltage drops below 4.8 V, it must rise

back to 5.8 V to enable (turn-on) the power MOSFET.

Over-Temperature Protection

The thermal shutdown circuitry senses the die temperature.

The threshold is set at 142 °C typical with a 75 °C hysteresis.

When the die temperature rises above this threshold (142 °C) the

power MOSFET is disabled and remains disabled until the die

temperature falls by 75 °C, at which point it is re-enabled.

Current Limit

The current limit circuit senses the current in the power MOSFET.

When this current exceeds the internal threshold (ILIMIT), the

power MOSFET is turned off for the remainder of that cycle.

The leading edge blanking circuit inhibits the current limit

comparator for a short time (tLEB) after the power MOSFET

is turned on. This leading edge blanking time has been set so

that current spikes caused by capacitance and rectiﬁ er reverse

recovery time will not cause premature termination of the

switching pulse.

Auto-Restart

In the event of a fault condition such as output overload, output

short circuit, or an open loop condition, LinkSwitch-XT enters

into auto-restart operation. An internal counter clocked by the

oscillator gets reset every time the FB pin is pulled high. If the

FB pin is not pulled high for approximately 40 ms, the power

MOSFET switching is disabled for 800 ms. The auto-restart

alternately enables and disables the switching of the power

MOSFET until the fault condition is removed.

Figure 4. Frequency Jitter.

LNK362-364

2-4

Rev. E 11/08

Applications Example

A 2 W CV Adapter

The schematic shown in Figure 5 is a typical implementation of

a universal input, 6.2 V ±7%, 322 mA adapter using LNK362.

This circuit makes use of the Clampless technique to eliminate the

primary clamp components and reduce the cost and complexity

of the circuit.

The EcoSmart features built into the LinkSwitch-XT family

allow this design to easily meet all current and proposed

energy efﬁ ciency standards, including the mandatory California

Energy Commission (CEC) requirement for average operating

efﬁ ciency.

The AC input is rectiﬁ ed by D1 to D4 and ﬁ ltered by the bulk

storage capacitors C1 and C2. Resistor RF1 is a ﬂ ameproof,

fusible, wire wound type and functions as a fuse, inrush current

limiter and, together with the π ﬁ lter formed by C1, C2, L1

and L2, differential mode noise attenuator. Resistor R1 damps

ringing caused by L1 and L2.

This simple input stage, together with the frequency jittering of

LinkSwitch-XT, a low value Y1 capacitor and PI’s E-Shield™

windings within T1, allow the design to meet both conducted

and radiated EMI limits with >10 dBμV margin. The low value

of CY1 is important to meet the requirement for a very low

touch current (the line frequency current that ﬂ ows through

CY1) often speciﬁ ed for adapters, in this case <10 μA.

The rectiﬁ ed and ﬁ ltered input voltage is applied to the primary

winding of T1. The other side of the primary is driven by the

integrated MOSFET in U1. No primary clamp is required as the

low value and tight tolerance of the LNK362 internal current

limit allows the transformer primary winding capacitance to

provide adequate clamping of the leakage inductance drain

voltage spike.

The secondary of the ﬂ yback transformer T1 is rectiﬁ ed by D5,

a low cost, fast recovery diode, and ﬁ ltered by C4, a low ESR

capacitor. The combined voltage drop across VR1, R2 and the

LED of U2 determines the output voltage. When the output

voltage exceeds this level, current will ﬂ ow through the LED

of U2. As the LED current increases, the current fed into the

FEEDBACK pin of U1 increases until the turnoff threshold

current (~49 μA) is reached, disabling further switching cycles

of U1. At full load, almost all switching cycles will be enabled,

and at very light loads, almost all the switching cycles will be

disabled, giving a low effective frequency and providing high

light load efﬁ ciency and low no-load consumption.

Resistor R3 provides 1 mA through VR1 to bias the Zener

closer to its test current. Resistor R2 allows the output voltage

to be adjusted to compensate for designs where the value of the

Zener may not be ideal, as they are only available in discrete

voltage ratings. For higher output accuracy, the Zener may be

replaced with a reference IC such as the TL431.

Figure 5. 2 W Universal Input CV Adapter Using LNK362.

1N4005

1N4934

PI-4162-110205

1N4005

RF1

8.2 Ω

2.5 W

3.9 k

1/8 W

1 k

1/8 W

390 Ω

1/8 W

6.2 V,

322 mA

85-265

VRMS

1 mH

3.3 μF

400 V

3.3 μF

400 V

CY1

100 pF

250 VAC

330 μF

16 V

VR1

BZX79-

B5V1

5.1 V, 2%

EE16

NC NC

100 nF

50 V

PC817A

LNK362P

LinkSwitch-XT

LNK362-364

2-5

Rev. E 11/08

The LinkSwitch-XT is completely self-powered from the DRAIN

pin, requiring only a small ceramic capacitor C3 connected to

the BYPASS pin. No auxiliary winding on the transformer is

required.

Key Application Considerations

LinkSwitch-XT Design Considerations

Output Power Table

The data sheet maximum output power table (Table 1) represents

the maximum practical continuous output power level that can

be obtained under the following assumed conditions:

1. The minimum DC input voltage is 90 V or higher for 85 VAC

input, or 240 V or higher for 230 VAC input or 115 VAC

with a voltage doubler. The value of the input capacitance

should be large enough to meet these criteria for AC input

designs.

2. Secondary output of 6 V with a fast PN rectiﬁ er diode.

3. Assumed efﬁ ciency of 70%.

4. Voltage only output (no secondary-side constant current

circuit).

5. Discontinuous mode operation (KP >1).

6. A primary clamp (RCD or Zener) is used.

7. The part is board mounted with SOURCE pins soldered

to a sufﬁ cient area of copper to keep the SOURCE pin

temperature at or below 100 °C.

8. Ambient temperature of 50 °C for open frame designs

and an internal enclosure temperature of 60 °C for adapter

designs.

Below a value of 1, KP is the ratio of ripple to peak primary

current. Above a value of 1, KP is the ratio of primary MOSFET

OFF time to the secondary diode conduction time. Due to

the ﬂ ux density requirements described below, typically a

LinkSwitch-XT design will be discontinuous, which also has

the beneﬁ ts of allowing lower cost fast (instead of ultra-fast)

output diodes and reducing EMI.

Clampless Designs

Clampless designs rely solely on the drain node capacitance

to limit the leakage inductance induced peak drain-to-source

voltage. Therefore, the maximum AC input line voltage, the

value of VOR, the leakage inductance energy, a function of

leakage inductance and peak primary current, and the primary

winding capacitance determine the peak drain voltage. With no

signiﬁ cant dissipative element present, as is the case with an

external clamp, the longer duration of the leakage inductance

ringing can increase EMI.

The following requirements are recommended for a universal

input or 230 VAC only Clampless design:

1. A Clampless design should only be used for PO ≤ 2.5 W,

using the LNK362† and a VOR** ≤ 90 V.

2. For designs where PO ≤ 2 W, a two-layer primary should be

used to ensure adequate primary intra-winding capacitance

in the range of 25 pF to 50 pF.

3. For designs where 2 < PO ≤ 2.5 W, a bias winding should be

added to the transformer using a standard recovery rectiﬁ er

diode to act as a clamp. This bias winding may also be used

to externally power the device by connecting a resistor from

the bias-winding capacitor to the BYPASS pin. This inhibits

the internal high-voltage current source, reducing device

dissipation and no-load consumption.

4. For designs where PO > 2.5 W Clampless designs are not

practical and an external RCD or Zener clamp should be

used.

5. Ensure that worst-case high line, peak drain voltage is below

the BVDSS speciﬁ cation of the internal MOSFET and ideally

≤ 650 V to allow margin for design variation.

†For 110 VAC only input designs it may be possible to extend

the power range of Clampless designs to include the LNK363.

However, the increased leakage ringing may degrade EMI

performance.

**VOR is the secondary output plus output diode forward voltage

drop that is reﬂ ected to the primary via the turns ratio of the

transformer during the diode conduction time. The VOR adds

to the DC bus voltage and the leakage spike to determine the

peak drain voltage.

Audible Noise

The cycle skipping mode of operation used in LinkSwitch-XT

can generate audio frequency components in the transformer.

To limit this audible noise generation, the transformer should

be designed such that the peak core ﬂ ux density is below

1500 Gauss (150 mT). Following this guideline and using the

standard transformer production technique of dip varnishing

practically eliminates audible noise. Vacuum impregnation

of the transformer should not be used due to the high primary

capacitance and increased losses that result. Higher ﬂ ux densities

are possible, however careful evaluation of the audible noise

performance should be made using production transformer

samples before approving the design.

Ceramic capacitors that use dielectrics, such as Z5U, when

used in clamp circuits may also generate audio noise. If this is

the case, try replacing them with a capacitor having a different

dielectric or construction, for example a ﬁ lm type.

LinkSwitch-XT Layout Considerations

See Figure 6 for a recommended circuit board layout for

LinkSwitch-XT (P & G package).

Single Point Grounding

Use a single point ground connection from the input ﬁ lter capacitor

to the area of copper connected to the SOURCE pins.

LNK362-364

2-6

Rev. E 11/08

Bypass Capacitor CBP

The BYPASS pin capacitor should be located as near as possible

to the BYPASS and SOURCE pins.

Primary Loop Area

The area of the primary loop that connects the input ﬁ lter

capacitor, transformer primary and LinkSwitch-XT together

should be kept as small as possible.

Primary Clamp Circuit

A clamp is used to limit peak voltage on the DRAIN pin at

turn-off. This can be achieved by using an RCD clamp or a

Zener (~200 V) and diode clamp across the primary winding.

In all cases, to minimize EMI, care should be taken to minimize

the circuit path from the clamp components to the transformer

and LinkSwitch-XT.

Thermal Considerations

The copper area underneath the LinkSwitch-XT acts not only

as a single point ground, but also as a heatsink. As this area is

connected to the quiet source node, it should be maximized for

good heat sinking of LinkSwitch-XT. The same applies to the

cathode of the output diode.

Y-Capacitor

The placement of the Y-type cap should be directly from the

primary input ﬁ lter capacitor positive terminal to the common/

return terminal of the transformer secondary. Such a placement

will route high magnitude common-mode surge currents away

from the LinkSwitch-XT device. Note that if an input pi (C, L, C)

EMI ﬁ lter is used, then the inductor in the ﬁ lter should be placed

between the negative terminals of the input ﬁ lter capacitors.

Optocoupler

Place the optocoupler physically close to the LinkSwitch-XT to

minimize the primary-side trace lengths. Keep the high current,

high-voltage drain and clamp traces away from the optocoupler

to prevent noise pick up.

Output Diode

For best performance, the area of the loop connecting the

secondary winding, the output diode and the output ﬁ lter

HV DC

INPUT

OUT

TOP VIEW

PI-4155-102705

Input Filter

Capacitor

CBP

Output Filter

Capacitor

Maximize hatched copper

areas ( ) for optimum

heatsinking

LinkSwitch-XT

Opto-

coupler

Y1-

Capacitor

Figure 6. Recommended Printed Circuit Layout for LinkSwitch-XT using P Package in a Flyback Converter Conﬁ guration.

LNK362-364

2-7

Rev. E 11/08

capacitor should be minimized. In addition, sufﬁ cient copper

area should be provided at the anode and cathode terminals

of the diode for heat sinking. A larger area is preferred at the

quiet cathode terminal. A large anode area can increase high

frequency radiated EMI.

Quick Design Checklist

As with any power supply design, all LinkSwitch-XT designs

should be veriﬁ ed on the bench to make sure that component

speciﬁ cations are not exceeded under worst-case conditions. The

following minimum set of tests is strongly recommended:

1. Maximum drain voltage – Verify that VDS does not exceed

650 V at the highest input voltage and peak (overload) output

power. The 50 V margin to the 700 V BVDSS speciﬁ cation

gives margin for design variation, especially in Clampless

designs.

2. Maximum drain current – At maximum ambient temperature,

maximum input voltage and peak output (overload) power,

verify drain current waveforms for any signs of transformer

saturation and excessive leading-edge current spikes at startup.

Repeat under steady state conditions and verify that the leading-

edge current spike event is below ILIMIT(MIN) at the end of the

tLEB(MIN). Under all conditions, the maximum drain current

should be below the speciﬁ ed absolute maximum ratings.

3. Thermal Check – At speciﬁ ed maximum output power,

minimum input voltage and maximum ambient temperature,

verify that the temperature speciﬁ cations are not exceeded

for LinkSwitch-XT, transformer, output diode and output

capacitors. Enough thermal margin should be allowed for

part-to-part variation of the RDS(ON) of LinkSwitch-XT as

speciﬁ ed in the data sheet. Under low line, maximum power,

a maximum LinkSwitch-XT SOURCE pin temperature of

105 °C is recommended to allow for these variations.

Design Tools

Up-to-date information on design tools can be found at the

Power Integrations web site: www.powerint.com.

Figure 7. Recommended Printed Circuit Layout for LinkSwitch-XT using D Package in a Flyback Converter Conﬁ guration.

HV DC

INPUT

TOP VIEW

PI-4585-021607

OUT

Input Filter

Capacitor

CBP

Output Filter

Capacitor

Maximize hatched copper

areas ( ) for optimum

heatsinking

Opto-

coupler

Y1-

Capacitor

LinkSwitch-XT

LNK362-364

2-8

Rev. E 11/08

ABSOLUTE MAXIMUM RATINGS(1,5)

DRAIN Voltage .................................. .............-0.3 V to 700 V

Peak DRAIN Current: LNK362................200 mA (375 mA)(2)

LNK363/364.........400 mA (750 mA)(2)

FEEDBACK Voltage ........................................... -0.3 V to 9 V

FEEDBACK Current ...................................................100 mA

BYPASS Voltage.................................................. -0.3 V to 9 V

Storage Temperature .....................................-65 °C to 150 °C

Operating Junction Temperature(3) ................-40 °C to 150 °C

Lead Temperature(4) ....................................................... 260 °C

Notes:

1. All voltages referenced to SOURCE, TA = 25 °C.

2. The higher peak DRAIN current is allowed while the

DRAIN voltage is simultaneously less than 400 V.

3. Normally limited by internal circuitry.

4. 1/16 in. from case for 5 seconds.

5. Maximum ratings speciﬁ ed may be applied, one at a time,

without causing permanent damage to the product.

Exposure to Absolute Maximum Rating conditions for

extended periods of time may affect product reliability.

Parameter Symbol

Conditions

SOURCE = 0 V; TJ = -40 to 125 °C

See Figure 8

(Unless Otherwise Speciﬁ ed)

Min Typ Max Units

CONTROL FUNCTIONS

Output Frequency fOSC TJ = 25 °C Average 124 132 140 kHz

Peak-Peak Jitter 9

Maximum Duty

Cycle DCMAX S2 Open 60 %

FEEDBACK Pin

Turnoff Threshold

Current

IFB TJ = 25 °C 30 49 68 μA

FEEDBACK Pin

Voltage at Turnoff

Threshold

VFB

TJ = 0 °C to

125 °C

LNK362 1.55 1.65 1.75

LNK363-364 1.53 1.63 1.73

DRAIN Supply

Current

IS1

VFB ≥2 V

(MOSFET Not Switching)

See Note A

200 250 μA

IS2

FEEDBACK Open

(MOSFET

Switching)

250 300 μA

BYPASS Pin

Charge Current

ICH1

VBP = 0 V, TJ = 25 °C

See Note C -5.5 -3.5 -1.8

ICH2

VBP = 4 V, TJ = 25 °C

See Note C -3.8 -2.3 -1.0

BYPASS Pin

Voltage VBP 5.55 5.8 6.10 V

BYPASS Pin

Voltage Hysteresis VBPH 0.8 1.0 1.2 V

THERMAL IMPEDANCE

Thermal Impedance: P or G Package:

(θJA) ........................... 70 °C/W(3); 60 °C/W(4)

(θJC)(1) ............................................... 11 °C/W

D Package:

(θJA) ..................... .... 100 °C/W(3); 80 °C/W(4)

(θJC)(2) ............................................... 30 °C/W

Notes:

1. Measured on pin 2 (SOURCE) close to plastic interface.

2. Measured on pin 8 (SOURCE) close to plastic interface.

3. Soldered to 0.36 sq. in. (232 mm2), 2 oz. (610 g/m2) copper clad.

4. Soldered to 1 sq. in. (645 mm2), 2 oz. (610 g/m2) copper clad.

LNK362-364

2-9

Rev. E 11/08

Parameter Symbol

Conditions

SOURCE = 0 V; TJ = -40 to 125 °C

See Figure 8

(Unless Otherwise Speciﬁ ed)

Min Typ Max Units

CONTROL FUNCTIONS (cont)

BYPASS Pin

Supply Current IBPSC See Note D 68 μA

CIRCUIT PROTECTION

Current Limit

ILIMIT

(See

Note E)

di/dt = 30 mA/μs

TJ = 25 °CLNK362 130 140 150

di/dt = 42 mA/μs

TJ = 25 °CLNK363 195 210 225

di/dt = 50 mA/μs

TJ = 25 °CLNK364 233 250 268

Power Coefﬁ cient I2f

di/dt = 30 mA/μs

TJ = 25 °CLNK362 2199 2587

A2Hz

di/dt = 42 mA/μs

TJ = 25 °CLNK363 4948 5821

di/dt = 50 mA/μs

TJ = 25 °CLNK364 7425 8250

Leading Edge

Blanking Time tLEB

TJ = 25 °C

See Note F

LNK362 300 375 ns

LNK363/364 170 250

Current Limit

Delay tILD

TJ = 25 °C

See Note F 125 ns

Thermal

Shutdown

Temperature

TSD 135 142 150 °C

Thermal

Shutdown

Hysteresis

TSHD See Note G 75 °C

OUTPUT

ON-State

Resistance RDS(ON)

LNK362

ID = 14 mA

TJ = 25 °C4855

TJ = 100 °C7688

LNK363

ID = 21 mA

TJ = 25 °C2933

TJ = 100 °C4654

LNK364

ID = 25 mA

TJ = 25 °C2428

TJ = 100 °C3845

OFF-State Drain

Leakage Current IDSS

VBP = 6.2 V, VFB ≥2 V,

VDS = 560 V,

TJ = 125 °C

50 μA

LNK362-364

2-10

Rev. E 11/08

Parameter Symbol

Conditions

SOURCE = 0 V; TJ = -40 to 125 °C

See Figure 8

(Unless Otherwise Speciﬁ ed)

Min Typ Max Units

OUTPUT (cont)

Breakdown

Voltage BVDSS

VBP = 6.2 V, VFB ≥ 2 V,

See Note H, TJ = 25 °C700 V

DRAIN Supply

Voltage 50 V

Output Enable

Delay tEN See Figure 10 10 μs

Output Disable

Setup Time tDST 0.5 μs

Auto-Restart

ON-Time tAR

TJ = 25 °C

See Note I

LNK362 40 ms

LNK363-364 45

Auto-Restart Duty

Cycle DCAR 5%

NOTES:

A. Total current consumption is the sum of IS1 and IDSS when FEEDBACK pin voltage is ≥2 V (MOSFET not

switching) and the sum of IS2 and IDSS when FEEDBACK pin is shorted to SOURCE (MOSFET switching).

B Since the output MOSFET is switching, it is difﬁ cult to isolate the switching current from the supply current at the

DRAIN. An alternative is to measure the BYPASS pin current at 6 V.

C. See Typical Performance Characteristics section Figure 15 for BYPASS pin startup charging waveform.

D. This current is only intended to supply an optional optocoupler connected between the BYPASS and FEEDBACK

pins and not any other external circuitry.

E. For current limit at other di/dt values, refer to Figure 14.

F. This parameter is guaranteed by design.

G. This parameter is derived from characterization.

H. Breakdown voltage may be checked against minimum BVDSS speciﬁ cation by ramping the DRAIN pin voltage up

to but not exceeding minimum BVDSS.

I. Auto-restart on time has the same temperature characteristics as the oscillator (inversely proportional to

frequency).

LNK362-364

2-11

Rev. E 11/08

Figure 8. LinkSwitch-XT General Test Circuit.

PI-3490-060204

50 V50 V

DFB

470 kΩ

0.1 μF

470 Ω

5 W

PI-2048-033001

DRAIN

VOLTAGE

0 V

90%

10%

90%

D = t1

PI-3707-112503

tEN

MAX

tP = 1

fOSC

DRAIN

(internal signal)

Figure 9. LinkSwitch-XT Duty Cycle Measurement. Figure 10. LinkSwitch-XT Output Enable Timing.

LNK362-364

2-12

Rev. E 11/08

200

300

350

400

250

04286 101214161820

DRAIN Voltage (V)

DRAIN Current (mA)

PI-4093-081605

150

100

25 °C

100 °C

Scaling Factors:

LNK362 0.5

LNK363 0.8

LNK364 1.0

Typical Performance Characteristics

Figure 15. BYPASS Pin Startup Waveform.

1.1

1.0

0.9

-50 -25 0 25 50 75 100 125 150

Junction Temperature (°C)

Breakdown Voltage

(Normalized to 25 °C)

PI-2213-012301

00.2 0.4 0.6 0.8 1.0

Time (ms)

PI-2240-012301

BYPASS Pin Voltage (V)

Figure 11. Breakdown vs. Temperature.

Figure 13. Current Limit vs. Temperature. Figure 14. Current Limit vs. di/dt.

Figure 16. Output Characteristics.

Figure 12. Frequency vs. Temperature.

TBD

Temperature (°C)

PI-4091-081505

Current Limit

(Normalized to 25 °C)

1.0

1.2

1.4

0.8

0.6

0.4

0.2

-50 0 50 100 150

1.2

1.0

0.8

0.6

0.4

0.2

-50 -25 0 25 50 75 100 125

Junction Temperature (°C)

PI-2680-012301

Output Frequency

(Normalized to 25 °C)

Normalized di/dt

PI-4092-081505

Normalized Current Limit

1.0

1.2

1.4

0.8

0.6

0.4

0.2

12345

LNK362

LNK363

LNK364

Normalized

di/dt = 1

30 mA/μs

42 mA/μs

50 mA/μs

Normalized

Current

Limit = 1

140 mA

210 mA

250 mA

LNK362-364

2-13

Rev. E 11/08

Drain Voltage (V)

Drain Capacitance (pF)

PI-4094-081605

0 100 200 300 400 500 600

100

1000

Scaling Factors:

LNK362 0.5

LNK363 0.8

LNK364 1.0

Figure 17. COSS vs. Drain Voltage.

Typical Performance Characteristics (cont.)

PART ORDERING INFORMATION

LinkSwitch Product Family

XT Series Number

Package Identiﬁ er

G Plastic Surface Mount DIP

P Plastic DIP

D Plastic SO-8

Lead Finish

N Pure Matte Tin (RoHS Compliant)

GRoHS Compliant and Halogen Free (P and D package

only)

Tape & Reel and Other Options

Blank Standard Conﬁ gurations

TL Tape & Reel, 1 k pcs minimum for G Package. 2.5 k pcs

for D Package. Not available for P Package.

LNK 364 G N - TL

LNK362-364

2-14

Rev. E 11/08

Notes:

1. Package dimensions conform to JEDEC specification

MS-001-AB (Issue B 7/85) for standard dual-in-line (DIP)

package with .300 inch row spacing.

2. Controlling dimensions are inches. Millimeter sizes are

shown in parentheses.

3. Dimensions shown do not include mold flash or other

protrusions. Mold flash or protrusions shall not exceed

.006 (.15) on any side.

4. Pin locations start with Pin 1, and continue counter-clock-

wise to Pin 8 when viewed from the top. The notch and/or

dimple are aids in locating Pin 1. Pin 6 is omitted.

5. Minimum metal to metal spacing at the package body for

the omitted lead location is .137 inch (3.48 mm).

6. Lead width measured at package body.

7. Lead spacing measured with the leads constrained to be

perpendicular to plane T.

.008 (.20)

.015 (.38)

.300 (7.62) BSC

(NOTE 7)

.300 (7.62)

.390 (9.91)

.367 (9.32)

.387 (9.83)

.240 (6.10)

.260 (6.60)

.125 (3.18)

.145 (3.68)

.057 (1.45)

.068 (1.73)

.120 (3.05)

.140 (3.56)

.015 (.38)

MINIMUM

.048 (1.22)

.053 (1.35)

.100 (2.54) BSC

.014 (.36)

.022 (.56)

-E-

Pin 1

SEATING

PLANE

-D-

-T-

P08B

DIP-8B

PI-2551-121504

D S .004 (.10)

⊕

T E D S .010 (.25) M

⊕

(NOTE 6)

.137 (3.48)

MINIMUM

SMD-8B

PI-2546-121504

.004 (.10)

.012 (.30)

.036 (0.91)

.044 (1.12)

.004 (.10)

0 -

° 8°

.367 (9.32)

.387 (9.83)

.048 (1.22) .009 (.23)

.053 (1.35)

.032 (.81)

.037 (.94)

.125 (3.18)

.145 (3.68)

-D-

Notes:

1. Controlling dimensions are

inches. Millimeter sizes are

shown in parentheses.

2. Dimensions shown do not

include mold flash or other

protrusions. Mold flash or

protrusions shall not exceed

.006 (.15) on any side.

3. Pin locations start with Pin 1,

and continue counter-clock-

wise to Pin 8 when viewed

from the top. Pin 6 is omitted.

4. Minimum metal to metal

spacing at the package body

for the omitted lead location

is .137 inch (3.48 mm).

5. Lead width measured at

package body.

6. D and E are referenced

datums on the package

body.

.057 (1.45)

.068 (1.73)

(NOTE 5)

E S

.100 (2.54) (BSC)

.372 (9.45)

.240 (6.10) .388 (9.86)

.137 (3.48)

MINIMUM

.260 (6.60) .010 (.25)

-E-

Pin 1

D S .004 (.10)

⊕

G08B

.420

.046 .060 .060 .046

.080

Pin 1

.086

.186

.286

Solder Pad Dimensions

LNK362-364

2-15

Rev. E 11/08

PI-4526-040207

D07C

SO-8C

3.90 (0.154) BSC

Notes:

1. JEDEC reference: MS-012.

2. Package outline exclusive of mold flash and metal burr.

3. Package outline inclusive of plating thickness.

4. Datums A and B to be determined at datum plane H.

5. Controlling dimensions are in millimeters. Inch dimensions

are shown in parenthesis. Angles in degrees.

0.20 (0.008) C

1 4

26.00 (0.236) BSC

4.90 (0.193) BSC

0.10 (0.004) C

0.10 (0.004) C 2X

A-B

1.27 (0.050) BSC

7X 0.31 - 0.51 (0.012 - 0.020)

0.25 (0.010) M C A-B D

0.25 (0.010)

0.10 (0.004)

(0.049 - 0.065)

1.25 - 1.65

1.75 (0.069)

1.35 (0.053)

0.10 (0.004) C

1.27 (0.050)

0.40 (0.016)

GAUGE

PLANE

0 - 8

1.04 (0.041) REF 0.25 (0.010)

BSC

SEATING

PLANE

0.25 (0.010)

0.17 (0.007)

DETAIL A

SEATING PLANE

Pin 1 ID

+ +

4.90 (0.193)

1.27 (0.050) 0.60 (0.024)

2.00 (0.079)

Reference

Solder Pad

Dimensions

Revision Notes Date

B 1) Released Final Data Sheet. 11/05

C 1) Corrected Application Example section. 12/05

D 1) Added SO-8C package. 2/07

E 1) Updated Part Ordering Information section with Halogen Free 11/08

LNK362-364

2-16

Rev. E 11/08

For the latest updates, visit our website: www.powerint.com

Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability. Power

Integrations does not assume any liability arising from the use of any device or circuit described herein. POWER INTEGRATIONS MAKES

NO WARRANTY HEREIN AND SPECIFICALLY DISCLAIMS ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, THE IMPLIED

WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF THIRD PARTY RIGHTS.

Patent Information

The products and applications illustrated herein (including transformer construction and circuits external to the products) may be covered

by one or more U.S. and foreign patents, or potentially by pending U.S. and foreign patent applications assigned to Power Integrations. A

complete list of Power Integrations patents may be found at www.powerint.com. Power Integrations grants its customers a license under

certain patent rights as set forth at http://www.powerint.com/ip.htm.

Life Support Policy

POWER INTEGRATIONS PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR

SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF POWER INTEGRATIONS. As used herein:

A Life support device or system is one which, (i) is intended for surgical implant into the body, or (ii) supports or sustains life, and (iii)

whose failure to perform, when properly used in accordance with instructions for use, can be reasonably expected to result in signiﬁ cant

injury or death to the user.

A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause

the failure of the life support device or system, or to affect its safety or effectiveness.

The PI logo, TOPSwitch, TinySwitch, LinkSwitch, DPA-Switch, PeakSwitch, EcoSmart, Clampless, E-Shield, Filterfuse, StakFET, PI Expert

and PI FACTS are trademarks of Power Integrations, Inc. Other trademarks are property of their respective companies.

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