RT9043GB - Richtek - Datasheet.Directory

RT9043

DS9043-01 December 2009 www.richtek.com

Ordering Information

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High PSRR, Low Dropout, 400mA Adjustable LDO Regulator

General Description

The RT9043 is a high-performance, 400mA LDO regulator,

offering high PSRR and low dropout. The quiescent current

is as low as 35μA, further prolonging the battery life. The

RT9043 also works with low-ESR ceramic capacitors,

reducing the amount of board space necessary for power

applications, critical in handheld wireless devices.

The RT9043 consumes typical 0.7μA in shutdown mode.

The other features include low dropout voltage, high output

accuracy, current limit protection, and enable/shutdown

control. The RT9043 is available in the SOT-23-5 package.

Features

zAdjustable Output Voltage

zEnable/Shutdown Control

zWide Operating Voltage Range : 2.2V to 5.5V

zLow Dropout : 230mV at 400mA

zLow-Noise for RF Application

zUltra-Fast Response in Line/Load Transient

zCurrent Limit Protection

zHigh Power Supply Rejection Ratio

zOutput Only 1μμ

μμ

μF Capacitor Required for Stability

zRoHS Compliant and Halogen Free

Applications

zMega SIM Card

zCDMA/GSM Cellular Handsets

zPortable Information Appliances

zLaptop, Palmtops, Notebook Computers

zHand-Held Instruments

zMini PCI & PCI-Express Cards

zPCMCIA & New Cards

Note :

Richtek Green 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.

RT9043

Package Type

B : SOT-23-5

Operating Temperature Range

G : Green (Halogen Free with Commer-

cial Standard)

Typical Application Circuit

Pin Configurations

(TOP VIEW)

SOT-23-5

VIN GND EN

VOUT FB

VIN

GND

VOUT

RT9043 COUT

1µF

CIN

VIN VOUT

Chip Enable

10k

RT9043

DS9043-01 December 2009www.richtek.com

Absolute Maximum Ratings (Note 1)

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

zEN Input Voltage ----------------------------------------------------------------------------------------------------------- 6V

zPower Dissipation, PD @ TA = 25°C

SOT-23-5 -------------------------------------------------------------------------------------------------------------------- 0.4W

zPackage Thermal Resistance (Note 4)

SOT-23-5, θJA --------------------------------------------------------------------------------------------------------------- 250°C/W

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

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

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

zESD Susceptibility (Note 2)

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

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

Recommended Operating Conditions (Note 3)

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

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

Functional Pin Description

Pi n No. Pin Name Pin Function

1 VIN Voltage Input.

2 GND Ground.

3 EN Chip Enable (Active High).

4 FB Output Voltage Feedback.

5 VOUT Voltage Output.

Function Block Diagram

POR

OTP

VIN

VOUT

GND

MOSFET

Driver

Current

Limit

VREF

RT9043

DS9043-01 December 2009 www.richtek.com

Electrical Characteristics

Parameter Symbol Test Conditions Min Typ Max Units

Input Voltage Range VIN 2.2 -- 5.5 V

Reference Voltage VREF 1.188 1.200 1.212 V

Quiescent Current IQ I

OUT = 0mA -- 35 50 μA

Shutdown Current ISHDN V

EN = 0V -- 0.7 1.5 μA

Current Limit ILIM R

LOAD = 0Ω, 2.2V ≤ VIN < 5.5V 400 650 -- mA

Dropout Voltage VDROP I

OUT = 400mA -- 230 350 mV

Load Regulation ΔVLOAD 1mA < IOUT < 400mA

2.2V ≤ VIN < 5.5V -- -- 1 %

Line Regulation ΔVLINE VIN = (VOUT + 0.5V) to 5.5V,

IOUT = 1m A -- 0. 01 0.2 %/V

Threshold

Logic-Low Voltage VIL 0 -- 0.6

Logic-High Voltage VIH 1.6 -- 5.5

EN Pin Current IEN -- 0.1 1 μA

FB Pin Current IFB

-- 0.1 1 μA

Power Supply Rejection Ratio PSRR

f = 1kHz, IOUT = 10mA -- 67 -- dB

f = 10kHz, IOUT = 10mA -- 56 -- dB

Output Noise Voltage VON VOUT = 1.5V, COUT = 1μF,

IOUT = 0m A -- 30 -- μVRMS

Thermal Shutdown Temperature TSD -- 160 -- °C

Thermal Shutdown Recovery

Temperature -- 110 -- °C

(VIN = 3.7V, CIN = COUT = 1μF, IOUT = 20mA, TA = 25°C, unless otherwise specified)

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. Devices are ESD sensitive. Handling precaution is recommended.

Note 3. The device is not guaranteed to function outside its operating conditions.

Note 4. θJA is measured in the natural convection at TA = 25°C on a low effective thermal conductivity test board of JEDEC 51-3

thermal measurement standard.

RT9043

DS9043-01 December 2009www.richtek.com

Reference Voltage vs. Temperature

1.185

1.190

1.195

1.200

1.205

1.210

1.215

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature

Reference Voltage (V)

Quiescent Current vs. Temperature

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature

Quiescent Current (uA)

Dropout Voltage vs. Loa d Current

100

150

200

250

300

350

0 50 100 150 200 250 300 350 400

Load Current (mA)

Dropout Voltage (mV)

EN Threshold vs. Te mpe rature

0.6

0.7

0.8

0.9

1.1

1.2

1.3

1.4

1.5

1.6

-40-20 0 20406080100

Temperature

EN Threshold (V)

Current Limit vs. Temperature

450

475

500

525

550

575

600

625

650

675

700

-50 -25 0 25 50 75 100 125

Temperature

Current Limit (mA)

Typical Operating Characteristics

VIN = VEN = 3.3V, No Laod

(°C)

VIN = VEN = 3.3V, VOUT = 2.5V, No Laod

(°C)

TA = −40°C

TA = 25°C

TA = 125°C

VIN = VEN = 3.3V, VOUT = 2.5V

Rising

(°C)

Falling

VIN = 3.3V, No Laod

VIN = 3.3V, VOUT = 1.8V

(°C)

Current Limit vs. Input Voltage

500

525

550

575

600

625

650

675

700

22.533.544.555.5

Input Voltage (V)

Current Limit (mA)

VOUT = 1.8V

RT9043

DS9043-01 December 2009 www.richtek.com

Line Transient Response

Time (50μs/Div)

VIN

(V/Div)

VOUT

(20mV/Div)

VIN = 4V to 5V, VOUT = 2.5V,

ILOAD = 1mA, COUT = 1μF/X7R

Load Transient Response

Time (100μs/Div)

IOUT

(200mA/Div)

VOUT

(10mV/Div)

VIN = 3.3V, VOUT = 2.5V, ILOAD = 1mA to 400mA,

CIN = COUT = 1μF/X7R

Load Transient Response

Time (100μs/Div)

IOUT

(200mA/Div)

VOUT

(10mV/Div)

VIN = 3.3V, VOUT = 2.5V, ILOAD = 200mA to 400mA,

CIN = COUT = 1μF/X7R

Power On from EN

Time (5μs/Div)

VOUT

(1V/Div)

VEN

(5V/Div)

VIN = 3.3V, VOUT = 2.5V, No Load

Enable/Shutdown Response

Time (500μs/Div)

VIN = 5V, VOUT = 2.5V, ILOAD = 10mA

VOUT

(1V/Div)

VEN

(5V/Div)

PSRR

-80

-70

-60

-50

-40

-30

-20

-10

10 100 1000 10000 100000 1000000

Frequency (Hz)

PSRR(dB)

ILOAD = 10mA, CIN = COUT = 1μF/X7R

1K 10K 100K 1M

RT9043

DS9043-01 December 2009www.richtek.com

Application Information

Input Capacitor Selection

Like any low-dropout linear regulator, the external

capacitors used with the RT9043 must be carefully

selected for stability and performance. The input

capacitance is recommended to be at least 1μF, and can

be increased without limit. The input capacitor must be

located at a distance of less than 0.5 inch from the input

pin of the IC and returned to a clean ground plane. Any

high-quality ceramic capacitor or tantalum capacitor can

be used for the input capacitor. Using input capacitor with

larger capacitance and lower ESR (equivalent series

resistance) can obtain better PSRR and line transient

response.

Output Capacitor Selection

The output capacitor must meet both the requirements

for minimum capacitance and minimum ESR value in all

applications. The RT9043 is designed specifically to work

with low ESR ceramic output capacitor to save board

space and have better performance. Figure 1 shows the

allowable ESR range for stable operation as a function of

load current and output capacitance value. Use at least

1μF ceramic output capacitor which ESR is within the

stable operation range to ensure stability. Larger

capacitance can reduce noise and improve load transient

response, stability, and PSRR. The RT9043 can operate

with other types of output capacitor due to its wide stable

operation range. The output capacitor should be placed

less than 0.5 inch from the VOUT and returned to a clean

ground plane.

Region of Stable COUT ESR vs. Loa d Current

0.00

0.01

0.10

1.00

10.00

100.00

0 50 100 150 200 250 300 350 400

Load Current (mA)

Region of Stable C OUT ESR (ohm)

COUT = 1μF

Unstable Region

Stable Region

Unstable Region (Simulation Verity)

Region of Stable COUT ESR (Ω)

Output Voltage Setting

The output voltage divider R1 and R2 allows to adjust the

output voltage for various application as shown in Figure 2.

VOUT

R9043

GND

Figure 2. Output Voltage Setting

The output voltage is set according to the following

equation:

OUT FB R1

VV1

⎛⎞

⎜⎟

⎝⎠

Where VFB is the feedback reference voltage (1.2V typical).

Enable Function

The RT9043 features enable/shutdown function. The

voltage at the EN pin determines the enable/shutdown

state of the regulator. To ensure the regulator will switch

on, the enable control voltage must be greater than 1.6V.

The regulator will enter shutdown mode when the voltage

at EN pin falls below 0.6 volt. If the enable function is not

needed, EN pin should be pulled high or simply tied to

VIN to keep the regulator in on state.

PSRR

RT9043 features high power supply rejection ratio (PSRR),

which is defined as the ratio of output voltage change

against input voltage change.

OUT

PSRR 20 log V

⎛⎞

=×⎜⎟

⎝⎠

A low-dropout regulator with higher PSRR can provide better

line transient performance.

Current Limit

The RT9043 implements an independent current limit

circuit, which monitors and controls the pass element’s

gate voltage to limit the output current at 650mA (typ.). If

the current limit condition lasts for a long time, the regulator

temperature may increase high enough to damage the

regulator itself. There fore, RT9043 implements current

limit function and thermal protection function to prevent

Figure 1

RT9043

DS9043-01 December 2009 www.richtek.com

the regulator from damaging when the output is shorted

to ground.

Thermal Considerations

For continuous operation, do not exceed absolute

maximum operation junction temperature. 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) − TA ) / θJA

Where TJ(MAX) is the maximum operation junction

temperature, TA is the ambient temperature and the θJA is

the junction to ambient thermal resistance.

For recommended operating conditions specification of

RT9043, the maximum junction temperature is 125°C.

The junction to ambient thermal resistance θJA is layout

dependent. For SOT-23-5 packages, the thermal

resistance θJA is 250°C/W on the standard JEDEC 51-3

single layer thermal test board. The maximum power

dissipation at TA = 25°C can be calculated by following

formula :

PD(MAX) = (125°C − 25°C) / (250°C/W) = 0.4W for

SOT-23-5 packages

The maximum power dissipation depends on operating

ambient temperature for fixed TJ(MAX) and thermal

resistance θJA. For RT9043 packages, the Figure 3 of

derating curves allows the designer to see the effect of

rising ambient temperature on the maximum power

allowed.

Figure 3. Derating Curves for RT9043 Packages

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0 25 50 75 100 125

Ambient Temperature (°C)

Maximum Power Dissipation (W)

SOT-23-5

Single Layer PCB

RT9043

DS9043-01 December 2009www.richtek.com

Richtek Technology Corporation

Headquarter

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

Hsinchu, Taiwan, R.O.C.

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

Richtek Technology Corporation

Taipei Office (Marketing)

8F, No. 137, Lane 235, Paochiao Road, Hsintien City

Taipei County, Taiwan, R.O.C.

Tel: (8862)89191466 Fax: (8862)89191465

Email: marketing@richtek.com

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.

Outline Dimension

AA1

SOT-23-5 Surface Mount Package

Dimensions In Millimeters Dimensions In Inches

Symbol Min Max Min Max

A 0.889 1.295 0.035 0.051

A1 0.000 0.152 0.000 0.006

B 1.397 1.803 0.055 0.071

b 0.356 0.559 0.014 0.022

C 2.591 2.997 0.102 0.118

D 2.692 3.099 0.106 0.122

e 0.838 1.041 0.033 0.041

H 0.080 0.254 0.003 0.010

L 0.300 0.610 0.012 0.024