RT9027BGS - Richtek - Datasheet.Directory

RT9027A/B

DS9027A/B-02 April 2011 www.richtek.com

Pin Configurations

Ordering Information

(TOP VIEW)

SOP-8

Note :

Richtek products are :

` RoHS compliant and compatible with the current require-

ments of IPC/JEDEC J-STD-020.

` Suitable for use in SnPb or Pb-free soldering processes.

Line ar Fan Driver

General Description

The RT9027A/B is a high performance positive voltage

regulator designed for very low dropout voltage up to 0.5

Amps. The VSET voltage must be larger than 1V to guarantee

that VOUT is 1.6 times of VSET. When VSET is less than 1V,

the IC will be shutdown. The FON pin turns VOUT to fully-

on when FON is given low. For RT9027B (EN version),

FON pin is equivalent to EN pin. The RT9027A/B provides

excellent regulation over variations in line, load and

temperature. The RT9027A/B is available in the SOP-8

package.

Features

zVOUT Follows 1.6 Times of VSET

z150mV Dropout @ 0.5A

zOver Current and Over Temperature Protection

zFON Pin Turns VOUT Fully On

zRoHS Compliant and 100% Lead (Pb)-Free

Applications

zNotebook Computer Fan Driver

zBattery Powered System

zMotherboard

zPeripheral Card

GND

VIN

VSET

VOUT

GND

FON

GND

VIN

VSET

VOUT

GND

RT9027A

RT9027B

Typical Application Circuit

VIN

VSET

VOUT

GND

RT9027A/B

VOUT

2.2uF

VIN

COUT

CIN

VSET

FON/EN

FON/EN 1

5 to 8

Package Type

S : SOP-8

RT9027

Lead Plating System

P : Pb Free

G : Green (Halogen Free and Pb Free)

A : FON Function

B : EN Function

RT9027A/B

DS9027A/B-02 April 2011www.richtek.com

Functional Pin Description

Pin No. Pin N ame Pin Function

FON Internal pulled high. For RT9027A, the IC will be fully turned on when this pin’s voltage is

below 0.4V.

EN Internal pulled high. For RT9027B, the IC will be shutdown when this pin’s voltage is

below 0.4V.

2 VIN Input Voltage Pin.

3 VOUT Output Voltage Pin.

4 VSET

This pin is used for output voltage setting. It is necessary to make this pin higher than 1V

to guarantee VOUT to be 1.6 times of VSET. The IC will be shutdown when this pin voltage

is below 1V.

5 to 8 GND Ground.

Function Block Diagram

OCP

VSET POR

(Enable)

VIN POR BIAS+Thermal

Shutdown

0.6

Logic

VIN

VSET

VOUT

GND

FON/EN

RT9027A/B

DS9027A/B-02 April 2011 www.richtek.com

Absolute Maximum Ratings (Note 1)

zSupply Input Voltage, VIN ---------------------------------------------------------------------------------------------- 6V

zEN, FON, VSET Voltage ----------------------------------------------------------------------------------------------- 6V

zPower Dissipation, PD @ TA = 25°C

SOP-8 ---------------------------------------------------------------------------------------------------------------------- 1.053W

zPackage Thermal Resistance (Note 2)

SOP-8, θJA ----------------------------------------------------------------------------------------------------------------- 95°C/W

zLead Temperature (Soldering, 10 sec.) ----------------------------------------------------------------------------- 260°C

zJunction Temperature --------------------------------------------------------------------------------------------------- 150°C

zStorage Temperature Range ------------------------------------------------------------------------------------------- −65°C to 150°C

zESD Susceptibility (Note 3)

HBM ------------------------------------------------------------------------------------------------------------------------ 2kV

MM -------------------------------------------------------------------------------------------------------------------------- 200V

Recommended Operating Conditions (Note 4)

zSupply Input Voltage, VIN ---------------------------------------------------------------------------------------------- 4.5V to 5.5V

zJunction Temperature Range ------------------------------------------------------------------------------------------ −40°C to 125°C

zAmbient Temperature Range ------------------------------------------------------------------------------------------ −40°C to 85°C

Electrical Characteristics

(VSET = 2V, VIN = 5V, IOUT = 0.5A, CIN = COUT = 2.2uF, TA = 25°C, unless otherwise specified)

To be continued

Parameter Symbol Test Conditions Min Typ Max Unit

Input Voltage

Input Voltage Range VIN 4.5 -- 5.5 V

Quiescent Current IQ I

OUT = 0A -- 300 -- uA

RT9027A VSET = 0V -- 10 ---

Shutdown

Current RT9027B ISHDN VEN = 0V -- 10 -- uA

Output Voltage

VOUT/VSET 1.552 1.6 1.648 V

Line Regulation ΔVLINE -- 0.2 0.5

Load Regulation ΔVLOAD -- 0.2 0.8 %

RON I

OUT = 0.5A, VIN = 5V, VSET = 3.3V -- 0.15 0.3 Ω

Current Limit ILIM 1.6 2 3.5 A

Short Current ISC -- 1.1 -- A

VIN UVLO Threshold Rising -- 2.5 --

VIN UVLO Hysteresis -- 0.7 -- V

VSET UVLO Threshold Rising -- 0.8 --

VSET UVLO Hysteresis -- 0.1 -- V

RT9027A/B

DS9027A/B-02 April 2011www.richtek.com

Note 1. Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are for

stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational

sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may

remain possibility to affect device reliability.

Note 2. θJA is measured in the natural convection at TA = 25°C on a high effective four layers thermal conductivity test board of

JEDEC 51-7 thermal measurement standard.

Note 3. Devices are ESD sensitive. Handling precaution is recommended.

Note 4. The device is not guaranteed to function outside its operating conditions.

Parameter Symbol Test Conditions Min Typ Max Unit

FO N Funct ion (RT9 027 A)

Logic-Low Voltage -- -- 0.4 V

FON Threshold Logic-High Voltage 1.6 -- -- V

FON Bias Pin Current V

FON = 0 -- 1.5 15 uA

EN Funct ion (RT9 027 B)

Logic-Low Voltage VIL -- -- 0.4 V

EN Threshold Logic-High Voltage VIH 1.6 -- -- V

EN Bias Pin Current IEN V

EN = 0 -- 10 15 uA

O ver Tem perature Protection

Thermal Shutdown Temperature TSD -- 140 -- °C

Thermal Shutdown Hysteresis -- 30 -- °C

RT9027A/B

DS9027A/B-02 April 2011 www.richtek.com

Typical Operating Characteristics

Ou tput Voltage vs . VSET Voltage

0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2

VSET Voltage (V)

Output Voltage (V)

IOUT = 0.5A

IOUT = 0A

Output Voltag e vs. Out put Cu rre nt

1.575

1.580

1.585

1.590

1.595

1.600

1.605

1.610

1.615

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

Output Current (A)

Output Voltage (V)

VSET = 1V

Output Voltage vs. Output Current

3.180

3.185

3.190

3.195

3.200

3.205

3.210

3.215

3.220

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

Output Current (A)

Output Voltage (V)

VSET = 2V

Output Vo ltage vs . Output Current

4.775

4.780

4.785

4.790

4.795

4.800

4.805

4.810

4.815

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

Output Current (A)

Output Voltage (V)

VSET = 3V

Output Voltage vs. Input Voltage

3.190

3.192

3.194

3.196

3.198

3.200

3.202

3.204

3.206

3.208

3.210

4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5

Input Voltage (V)

Output Voltage (V)

VSET = 2V

IOUT = 0.5A

IOUT = 0A

Output Voltage vs. Input Voltage

1.590

1.591

1.592

1.593

1.594

1.595

1.596

1.597

1.598

1.599

1.600

4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5

Input Voltage (V)

Output Voltage (V)

VSET = 1V

IOUT = 0.5A

IOUT = 0A

RT9027A/B

DS9027A/B-02 April 2011www.richtek.com

EN Threshold v s . Te m pe ratu re

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

-50 -25 0 25 50 75 100 125

Temperature

EN Threshold (V)

(°C)

Rising

Falling

VSET Thres hold vs. Temperature

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

-50 -25 0 25 50 75 100 125

Temperature

VSET Threshold (V)

(°C)

Rising

Falling

VIN UVLO Threshold v s. Temperature

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

-50-25 0 255075100125

Temperature

VIN

UVLO Threshold (V)

(°C)

Rising

Falling

Output Voltage vs. Temperature

1.56

1.57

1.58

1.59

1.60

1.61

1.62

1.63

1.64

-50-25 0 25 50 75100125

Temperature

Output Voltage (V)

(°C)

VSET = 1V, IOUT = 0A

Output Voltage vs. Tem p erature

4.75

4.76

4.77

4.78

4.79

4.80

4.81

4.82

4.83

-50-250 255075100125

Temperature

Output Voltage (V)

(°C)

VSET = 3V, IOUT = 0A

Output Voltage vs. Temperature

3.16

3.17

3.18

3.19

3.20

3.21

3.22

3.23

3.24

-50 -25 0 25 50 75 100 125

Temperature

Output Voltage (V)

(°C)

VSET = 2V, IOUT = 0A

RT9027A/B

DS9027A/B-02 April 2011 www.richtek.com

Quiescent Current vs. Temperature

150

170

190

210

230

250

270

290

310

330

350

-50-25 0 255075100125

Temperature

Quiescent Current (uA)

(°C)

VOUT = 3.2V

VOUT = 1.6V

Shutdown Current vs. Input Voltage

4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5

Input Voltage (V)

Shutdown Current (uA)

VSET = 1V

VSET = 2V

EN = 0V

Quiesc ent Current vs . Input Voltage

200

220

240

260

280

300

320

340

360

380

400

4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5

Input Voltage (V)

Quiescent Current (uA)

VOUT = 3.2V

VOUT = 1.6V

Dropout Voltage v s . Output Current

100

120

0 50 100 150 200 250 300 350 400 450 500

Output Current (mA)

Dropout Voltage (mV)

125°C

85°C

25°C

-40°C

Current Limit vs. VSET Voltage

1.6

1.7

1.8

1.9

2.0

2.1

2.2

2.3

2.4

0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2

VSET Voltage (V)

Output Current (A

)

Current Limit vs. Temperature

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

-50-250 255075100125

Temperature

Output Current (A

)

VSET = 1V

VSET = 2V

(°C)

RT9027A/B

DS9027A/B-02 April 2011www.richtek.com

Shutdown Current vs. Temperature

-50 -25 0 25 50 75 100 125

Temperature

Shutdown Current (uA)

VSET = 1V

VSET = 2V

EN = 0V

(°C)

Start Up for EN

Time (5us/Div)

VOUT

(1V/Div)

VEN

(5V/Div)

VSET = 1V, VIN = VEN = 5V

VOUT = 1.6V, IOUT = 500mA

IOUT

(0.5A/Div)

VIN

(5V/Div)

Start Up from VSET

Time (50us/Div)

VOUT

(1V/Div)

VSET

(1V/Div)

VSET = 1V, VIN = VEN = 5V

VOUT = 1.6V, IOUT = 500mA

IOUT

(0.5A/Div)

VIN

(5V/Div)

Short-Circuit Protection

Time (1ms/Div)

VOUT

(2V/Div)

VSET = 2V, VIN = VEN = 5V

VOUT = 3.2V

IOUT

(1A/Div)

Start Up from VIN

Time (2.5ms/Div)

VOUT

(1V/Div)

VSET = 1V, VIN = VEN = 5V

VOUT = 1.6V, IOUT = 500mA

IOUT

(0.5A/Div)

VIN

(5V/Div)

Short-Circuit Protection

Time (1ms/Div)

VOUT

(2V/Div)

VSET = 1V, VIN = VEN = 5V

VOUT = 1.6V

IOUT

(0.5A/Div)

RT9027A/B

DS9027A/B-02 April 2011 www.richtek.com

Line Transient Response

VIN

(V)

Time (100us/Div)

5.5

4.5

VOUT

(10mV/Div)

VSET = 1V, VEN = 5V, VOUT = 1.6V, IOUT = 500mA

Line Transient Response

VIN

(V)

Time (100us/Div)

5.5

4.5

VOUT

(10mV/Div)

VSET = 2V, VEN = 5V, VOUT = 3.2V, IOUT = 500mA

Load Transient Response

Time (250us/Div)

VOUT

(10mV/Div)

IOUT

(0.5A/Div)

VSET = 1V, VIN = VEN = 5V, VOUT = 1.6V

IOUT = 50mA to 0.5A

Load Transient Response

Time (250us/Div)

VOUT

(10mV/Div)

IOUT

(0.5A/Div)

VSET = 2V, VIN = VEN = 5V, VOUT = 3.2V

IOUT = 50mA to 0.5A

Line Transient Response

VIN

(V)

Time (100us/Div)

5.5

4.5

VOUT

(10mV/Div)

VSET = 2V, VEN = 5V, VOUT = 3.2V, IOUT = 10mA

Line Transient Response

VIN

(V)

Time (100us/Div)

5.5

4.5

VOUT

(10mV/Div)

VSET = 1V, VEN = 5V, VOUT = 1.6V, IOUT = 10mA

RT9027A/B

DS9027A/B-02 April 2011www.richtek.com

Application Information

Output Voltage Setting

The output voltage of RT9027AB is adjustable from 1.6V

to VIN by VSET voltage. It is set by internal voltage divider

resisters shown in function block diagram. The VOUT

voltage level is set as 1.6 times of VSET voltage level

when VSET is higher than 1V. When VSET is less than

0.8V, the IC will be shutdown.

Fully Turn On and Enable Logic Function

For RT9027A, pin1 named FON features fully turn on

function. When the FON pin is in logic low level, the IC

goes into fully turn on mode. During this condition, the

pass transistor will be fully turned on. The FON pin is

pulled to high level internally. For the enable function, it is

acceptable to use the VSET pin to control the IC. When

the VSET pin is in logic low level (<0.8V), the IC will be

shutdown.

For RT9027B, there is an EN pin for power on/off control.

When the EN pin is in logic low level, the IC will be

shutdown. During this condition, the pass transistor, error

amplifier, and band gap are turned off, reducing the supply

current to 10uA typical. The IC goes into operation mode

when the EN pin is in logic high level condition. The EN

pin is pulled to high level internally.

Capacitor Selection

Good bypassing is recommended from input to ground to

improve the AC performance. A 2.2uF input ceramic

capacitor or greater located as close as possible to the IC

is recommended. The RT9027AB is specifically designed

to use ceramic output capacitors as low as 2.2uF. The

ceramic capacitors offer significant cost and space savings,

along with high frequency noise filtering.

Current Limit and Short Circuit Protection

The RT9027A contains an independent current limit and

short circuit current protection to prevent the IC from

damaging in unexpected applications. The current limit

monitors and controls the pass transistor’s gate voltage,

limiting the output current to a certain level (2A typ.). When

the output voltage is less than 0.4V, the short circuit current

protection starts the current fold back function and limits

the output current at 0.8A (typ.).

Thermal Shutdown Protection

RT9027AB over temperature protection function limits

power dissipation to prevent this die from over temperature

damage. When the RT9027B operation junction

temperature exceeds 140°C, the over temperature

protection circuit starts the thermal shutdown function

and turns the pass transistor off. The pass transistor turns

on again after the junction temperature cools by 30°C.

For RT9027A, it lowers its OTP trip level to 110°C. It limits

IC case temperature under 100°C and provides maximum

safety to customer while output short circuit occurring.

Thermal Considerations

For continuous operation, do not exceed absolute

maximum operation junction temperature 125°C. The

power dissipation definition in device is:

PD = (VIN − VOUT) x IOUT + VIN x IQ

The maximum power dissipation depends on the thermal

resistance of IC package, PCB layout, the rate of

surroundings airflow and temperature difference between

junction to ambient. The maximum power dissipation can

be calculated by following formula :

PD(MAX) = (TJ(MAX) − T A) / θJA

Where TJ(MAX) is the maximum operation junction

temperature 125°C, TA is the ambient temperature and the

θJA is the junction to ambient thermal resistance. For

recommended operating conditions specification of

RT9027A/B, where TJ(MAX) is the maximum junction

temperature of the die (125°C) and TA is the maximum

ambient temperature.

Since the multiple GND pins of the SOP-8 package are

internally shorted and connected to lead frame, it is efficient

to dissipate the heat by adding copper area on GND

footprint. Figure 1 shows the relation about thermal

resistance θJA vs. copper area on a standard JEDEC 51-

7 (4 layer, 2S2P) thermal test board at TA = 25°C. For

example, with 10mm x 10mm copper area PCB, we can

obtain the lower thermal resistance about 45°C/W.

RT9027A/B

DS9027A/B-02 April 2011 www.richtek.com

The maximum power dissipation depends on operating

ambient temperature for fixed TJ(MAX) and thermal resistance

θJA . For RT9027AB packages, the Figure 2 of de-rating

curves allows the designer to see the effect of rising

ambient temperature on the maximum power allowed.

Figure 2. De-rating Curves for RT9027AB Package

Figure 1

0.2

0.4

0.6

0.8

1.2

1.4

1.6

1.8

2.2

2.4

0 25 50 75 100 125

Ambiemt Temperature (℃)

Maximum Power Dissipation (W)

100mm2

50mm2

25mm2

15mm2

min. layout

(°C)

JEDEC 4-layers PCB

100

020406080100

Copper Area (mm2)

Thermal Resistance θJA ( ℃/W)

θJA (°C/W)

The maximum power dissipation at TA = 25°C can be

calculated by following formula :

PD(MAX) = (125°C − 25°C) / 45°C/W = 2.22W for SOP-8

package

RT9027A/B

DS9027A/B-02 April 2011www.richtek.com

Richtek Technology Corporation

Headquarter

5F, No. 20, Taiyuen Street, Chupei City

Hsinchu, Taiwan, R.O.C.

Tel: (8863)5526789 Fax: (8863)5526611

Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit design,

specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be guaranteed

by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek.

Richtek Technology Corporation

Taipei Office (Marketing)

5F, No. 95, Minchiuan Road, Hsintien City

Taipei County, Taiwan, R.O.C.

Tel: (8862)86672399 Fax: (8862)86672377

Email: marketing@richtek.com

Outline Dimension

8-Lead SOP Plastic Package

Dimensions In Millimeters Dimensions In Inches

Symbol Min Max Min Max

A 4.801 5.004 0.189 0.197

B 3.810 3.988 0.150 0.157

C 1.346 1.753 0.053 0.069

D 0.330 0.508 0.013 0.020

F 1.194 1.346 0.047 0.053

H 0.170 0.254 0.007 0.010

I 0.050 0.254 0.002 0.010

J 5.791 6.200 0.228 0.244

M 0.400 1.270 0.016 0.050