RT9041A-10GE - Richtek - Datasheet.Directory

RT9041A/B

DS9041A/B-02 June 2012 www.richtek.com

Pin Configurations

Ordering Information

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.

(TOP VIEW)

RT9041B

RT9041A

SOT-23-6

500mA, Low Voltage, Low Dropout LDO with External Bias

Supply

General Description

The RT9041A/B are low voltage, low dropout linear

regulators with an external bias supply input. The bias

supply drives the gate of the internal N-Channel pass

transistor, making these devices ideal for applications that

require low voltage outputs from low voltage inputs.

RT9041A and RT9041B provide the fixed version from 1V

to 2V with 0.1V increment. Besides, RT9041B provides

more feature by using external resistors as adjustable

output voltage. The RT9041A/B include a current limit and

thermal shutdown that protects the regulator in the event

of a fault condition.

The RT9041A/B is available in a SOT-23-6 package.

Features

z±±

±±

±2% Output Voltage Accuracy

zNo Minimum Load Current Required

z1V to 5.5V Input Supply Voltage

z3V to 5.5V Input Bias Supply Voltage

zPGOOD Open-Drain Output (RT9041A)

zSupport both Fixed/Adjustable Mode (RT9041B)

zLow Supply Current

z5μμ

μμ

μA (max) Shutdown Supply Current

zRoHS Compliant and Halogen Free

Applications

zNotebook Computers

zVID Power Supplies

zPDAs

zCell Phones

zLow Dropout Regulators with External Bias Supply

VDD GND EN

VIN VOUT PGOOD

VDD GND EN

VIN VOUT ADJ

Marking Information

For marking information, contact our sales representative

directly or through a Richtek distributor located in your

area.

Package Type

E : SOT-23-6

Lead Plating System

G : Green (Halogen Free and Pb Free)

RT9041

Output Voltage

Fixed Only (RT9041A)

Fixed & Adjustable (RT9041B)

10 : 1.0V/Adj

11 : 1.1V/Adj

19 :1.9V/Adj

20 : 2.0V/Adj

A : Fixed with PGOOD

B : Fixed/Adjustable

RT9041A/B

DS9041A/B-02 June 2012www.richtek.com

Function Pin Description

Pin No.

RT9041A RT9041B

Pin Name Pin Function

1 1 VDD Supply Voltage of Control Circuitry.

6 6 VIN Supply Input Voltage.

5 5 VOUT Output Voltage.

3 3 EN Chip Enable (Active-High).

2 2 GND Ground.

4 -- PGOOD Power Good Open Drain Output.

-- 4 ADJ

Set the output voltage by the internal feedback resistors when ADJ is

grounded. If external feedback resistors is used, VOUT = VREF x (R1 + R2)/R2.

Typical Application Circuit

VDD

GND

VIN

VOUT

PGOOD

RT9041A

10µF

0.1µF

Chip Enable

3V to 5.5V 1V to 5.5V

100k

CIN

COUT

CVDD

VDD VIN

VOUT

VDD

GND

VIN

VOUT

ADJ

RT9041B

10µF

0.1µF

Chip Enable

3V to 5.5V 1V to 5.5V

CIN

COUT

CVDD

VDD

VOUT

VIN

RT9041A/B

DS9041A/B-02 June 2012 www.richtek.com

Function Block Diagram

RT9041A

RT9041B

VDD

OCP

Error

Amplifier

POR

GND

VIN

PGOOD

VOUT

0.8V

0.7V

OTP

Driver

VIN

OCP

Error

Amplifier

POR

GND

VIN

ADJ

VOUT

VDD

0.8V

OTP

Driver

VIN

Mode

RT9041A/B

DS9041A/B-02 June 2012www.richtek.com

Absolute Maximum Ratings (Note 1)

zSupply Input Voltage, VDD ---------------------------------------------------------------------------------------------- 6V

zInput Voltage, VIN --------------------------------------------------------------------------------------------------------- 6V

zOther Input/Output Pins ------------------------------------------------------------------------------------------------- 6V

zPower Dissipation, PD @ TA = 25°C

SOT-23-6 -------------------------------------------------------------------------------------------------------------------- 0.4W

zPackage Thermal Resistance (Note 2)

SOT-23-6, 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 (Note3)

HBM (Human Body Model) ---------------------------------------------------------------------------------------------- 2kV

Recommended Operating Conditions (Note 4)

zSupply Input Voltage, VIN ----------------------------------------------------------------------------------------------- 1V to 5.5V

zControl Voltage, VDD ----------------------------------------------------------------------------------------------------- 3V to 5.5V

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

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

Electrical Characteristics

Parameter Symbol Test Conditions Min Typ Max Unit

Input

Output Voltage Range

(for RT9041A only) VOUT 1 -- 2 V

Output Voltage Range

(for RT9041B only) VOUT 0.8 -- 2.5 V

Bias Input Under Voltage Lockout -- 2.7 -- V

VIN Shutdown Current ISHDN 1V < VIN < 5.5V, VIN = VOUT + 0.6V -- 1 5 μA

Quiescent Current IQ 3V < VDD < 5.5V -- 160 250 μA

VDD Shutdown Current ISHDN 3V < VDD < 5.5V -- 1 5 μA

Re gul ator Cha racte ris tics

Line Regulation ΔVOUT / ΔVIN IOUT = 10mA, 1.5V < VIN < 5.5V,

VIN = VOUT + 0.6V −0.15 -- 0.15 %/V

Load Regulation ΔVOUT / ΔIIN VIN = VOUT + 0.6V,

IOUT = 1mA to 500mA -- 0.2 1 %

Output Voltage Accuracy

(RT9041A) ΔVOUT V

IN = VOUT + 0.6V, IOUT = 10mA −2 -- 2 %

Output Voltage Accuracy

(RT9041B) ΔVOUT VIN = VOUT + 0.6V, IOUT = 10mA,

Short ADJ to GND −2 -- 2 %

Reference Voltage (RT9041B) I

OUT = 10mA 0.784 0.8 0.816 V

ILOAD = 300mA, VDD−VOUT ≥ 2.1V -- 200 300 mV

Dropout Voltage VDROP ILOAD = 500mA, VDD−VOUT ≥ 2.1V -- 300 500 mV

(VIN = 1.8V, ILOAD = 1mA, COUT = 10μF, TA = 25°C unless otherwise specified)

RT9041A/B

DS9041A/B-02 June 2012 www.richtek.com

Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are

stress ratings only, and 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 may

affect device reliability.

Note 2. θJA is measured at TA = 25°C on a low effective thermal conductivity single-layer test board per JEDEC 51-3

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

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

Note 5. Guaranteed by design.

Parameter Symbol Test Conditions Min Typ Max Unit

Current Limit ILIM R

LOAD = 0 550 700 1400 mA

Thermal-Shutdown Temp TSD 3V < VBIAS < 5.5V -- 160 -- °C

Thermal-Shutdown Hysteresis ΔTSD -- 20 -- °C

ADJ

ADJ Pin Threshold (RT9041B) -- 0.2 -- V

PGOOD Comparator

Comparator Threshold % of regulated output voltage -- 88 -- %

Comparator Hysteresis VHYST Note 5 -- 10 -- mV

Logic and I/O

Logic-High VIH 2.4 -- -- V

EN Threshold

Voltage Logic-Low VIL -- -- 0.8 V

EN Current IEN V

EN = 5V -- 12 -- μA

PGOOD Output Low Voltage

(RT9041A) PGOOD sinking 1mA -- -- 0.1 V

PGOOD Output High Leakage

Current (RT9041A) 0 < VPGOOD

< VIN −1 -- 1 μA

Dynamics

PGOOD Propagation Delay

(RT9041A) tPGOOD Rising edge within 5% of

regulation level 1 -- 4 ms

RT9041A/B

DS9041A/B-02 June 2012www.richtek.com

Typical Operating Characteristics

Quiescent Current v s. Temperature

130

140

150

160

170

180

190

200

210

-50 -25 0 25 50 75 100 125

Temperature (°C)

Quiescent Current (μA)1

VDD = 5V, VIN = 3.3V, VOUT = 2V, IOUT = 0mA

Reference Voltage v s. Temperature

0.76

0.77

0.78

0.79

0.80

0.81

0.82

0.83

0.84

-50 -25 0 25 50 75 100 125

Temperature (°C)

Reference Voltage (V)

VDD = 5V, VIN = 3.3V, VADJ = 0.8V, IOUT = 0mA

EN Threshold Voltage v s. Temperature

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 (°C)

Threshold Voltage (V)

Rising

VDD = 5V, VOUT = 1V

Falling

Output Voltage v s. Temperature

1.80

1.85

1.90

1.95

2.00

2.05

2.10

2.15

2.20

-50-25 0 25 50 75100125

Temperature (°C)

Output Voltage (V)

VDD = 5V, VIN = 3.3V, VOUT = 2V, IOUT = 0mA

Current Lim it vs. Tempe rature

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

-50 -25 0 25 50 75 100 125

Temperature (°C)

Current Limit (A)

VDD = 5V, VIN = 3.3V, VOUT = 2V, IOUT = 0mA

Dropout Voltage vs. Output Current

100

200

300

400

500

600

0 100 200 300 400 500

Output Current (mA)

Dropout Voltage (mV)

VDD = 5V

−40°C

25°C

125°C

RT9041A/B

DS9041A/B-02 June 2012 www.richtek.com

VDD UVLO vs. Tem pe rature

2.0

2.2

2.4

2.6

2.8

3.0

-50 -25 0 25 50 75 100 125

Temperature (°C)

UVLO (V)

Rising

VDD = 5V, VOUT = 1V

Falling

VIN UVLO vs. Tem pe rature

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-50 -25 0 25 50 75 100 125

Temperature (°C)

UVLO (V)

Rising

VDD = 5V, VOUT = 1V

Falling

PGOOD Response

Time (2.5ms/Div)

PGOOD

(1V/Div)

VEN

(5V/Div)

VOUT

(1V/Div)

VDD = 5V, VIN = 4V, IOUT = 40mA

Line Transient Response

Time (500μs/Div)

VOUT

(5mV/Div)

VDD = 5V, VIN = 3V to 4V, VOUT = 1V, IOUT = 10mA

VIN

(V)

Load Transient Response

Time (100μs/Div)

IOUT

(500mA/Div)

VOUT

(50mV/Div)

VDD = 5V, VIN = 3.3V, VOUT = 2V

IOUT = 10mA to 0.5A

PGOOD Timing vs. T emperat ure

-50 -25 0 25 50 75 100 125

Temperature (°C)

PGOOD Timing (ms)

VDD = 5V, VIN = 3.3V, VOUT = 1V

Rising

RT9041A/B

DS9041A/B-02 June 2012www.richtek.com

Line Transient Response

Time (500μs/Div)

VOUT

(5mV/Div)

VDD = 5V, VIN = 3V to 4V, VOUT = 1V, IOUT = 100mA

VIN

(V)

EN Response

Time (500μs/Div)

VEN

(5V/Div)

VOUT

(500mV/Div)

VDD = 5V, VIN = 3.3V, VOUT = 1V, IOUT = 0.5A

Noise

Time (10ms/Div)

VOUT

(200μV/Div)

VDD = VIN = 4.5V (By Battery),

VOUT = 1V, IOUT = 1mA

Noise

Time (10ms/Div)

VOUT

(200μV/Div)

VDD = VIN = 4.5V (By Battery),

VOUT = 1V, IOUT = 10mA

PSRR

-100

-80

-60

-40

-20

10 100 1000 10000 100000 1000000

Frequency (Hz)

PSRR (dB)

VDD = 5V, VIN = 3.3V to 3.4V, CIN = 1μF, COUT = 10μF

IOUT = 10mA

IOUT = 100mA

10 100 1k 10k 100k 1M

RT9041A/B

DS9041A/B-02 June 2012 www.richtek.com

Application Information

The RT9041A/B is a low voltage, low dropout linear

regulator with an external bias supply input, capable of

supporting an input voltage range from 1V to 5.5V with a

fixed output voltage from 1V to 2V in 0.1V increments.

Supply Voltage Setting

The bias supply voltage (VDD) operates from 3V to 5.5V.

For better efficiency, it is suggested to operate VDD at 5V

when the output voltage is higher than 1V. Figure 1 shows

the curves of the recommended VDD − VOUT range vs. the

dropout voltage (VIN − VOUT) values.

Figure 1. Dropout Voltage vs. VDD − VOUT

Output Voltage Setting

The RT9041B output voltage is also adjustable from 0.8V

to 2.5V via the external resistive voltage divider. The voltage

divider resistors can have values up to 800kΩ because of

the very high impedance and low bias current of the sense

comparator. The output voltage is set according to the

following equation :

⎛⎞

⎜⎟

⎝⎠

OUT REF R1

V = V x 1 + R2

where VREF is the reference voltage with a typical value of

0.8V.

Chip Enable Operation

The RT9041A/B goes into sleep mode when the EN pin is

in a logic low condition. In this condition, the pass transistor,

error amplifier, and band gap are all turned off, reducing

the supply current to 1μA (typ.). The EN pin can be directly

tied to VIN to keep the part on.

Current Limit

The RT9041A/B contains an independent current limit

circuitry, which monitors and controls the pass transistor’s

gate voltage, limiting the output current to 0.7A (typ.).

CIN and COUT Selection

Like any low dropout regulator, the external capacitors of

the RT9041A/B must be carefully selected for regulator

stability and performance. Using a capacitor of at least

10μF is suitable. The input capacitor must be located at a

distance of not more than 0.5 inch from the input pin of

the IC. Any good quality ceramic capacitor can be used.

However, a capacitor with larger value and lower ESR

(Equivalent Series Resistance) is recommended since it

will provide better PSRR and line transient response.

The RT9041A/B is designed specifically to work with low

ESR ceramic output capacitor for space saving and

performance consideration. Using a ceramic capacitor with

value at least 10μF and ESR larger than 2mΩ on the

RT9041A/B output ensures stability. Nevertheless, the

RT9041A/B can still work well with other types of output

capacitors due to its wide range of stable ESR. Figure 2

shows the allowable ESR range as a function of load

current for various output capacitance. Output capacitors

with larger capacitance can reduce noise and improve load

transient response, stability, and PSRR. The output

capacitor should be located at a distance of not more than

0.5 inch from the output pin of the RT9041A/B.

Dropout Voltage vs. VDD - VOUT

100

150

200

250

300

350

400

450

500

2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0

VDD - VOUT (V)

Dropout Voltage (mV)

IO = 500mA

IO = 300mA

RT9041A/B

DS9041A/B-02 June 2012www.richtek.com

Figure 2. Region of Stable COUT ESR vs. Load Current

Thermal Considerations

For continuous operation, do not exceed absolute

maximum junction temperature. The maximum power

dissipation depends on the thermal resistance of the IC

package, PCB layout, rate of surrounding airflow, and

difference between junction and ambient temperature. The

maximum power dissipation can be calculated by the

following formula :

PD(MAX) = (TJ(MAX) − TA) / θJA

where TJ(MAX) is the maximum junction temperature, TA is

the ambient temperature, and θJA is the junction to ambient

thermal resistance.

For recommended operating condition specifications, the

maximum junction temperature is 125°C. The junction to

ambient thermal resistance, θJA, is layout dependent. For

SOT-23-6 packages, the thermal resistance, θJA, is 250°C/

W on a standard JEDEC 51-3 single-layer thermal test

board. The maximum power dissipation at TA = 25°C can

be calculated by the following formula :

PD(MAX) = (125°C − 25°C) / (250°C/W) = 0.400W for

SOT-23-6 package

The maximum power dissipation depends on the operating

ambient temperature for fixed TJ(MAX) and thermal

resistance, θJA. The derating curve in Figure 3 allows the

designer to see the effect of rising ambient temperature

on the maximum power dissipation.

Figure 3. Derating Curve of Maximum Power Dissipation

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0 25 50 75 100 125

Ambient Temperature (°C)

Maximum Power Dissipation (W)1

Four-Layer PCB

Region of Stable COUT ESR vs . Loa d Current

0.001

0.010

0.100

1.000

10.000

100.000

0 100 200 300 400 500

Load Current (mA)

Region of Stable COUT ESR (Ω)

(Ω)

VDD = 5V, VIN = 2.5V, VOUT = 1V,

CVDD = 0.1μF, C IN = COUT = 10μF/X7R

Unstable Range

Stable Range

Simulation Verify

RT9041A/B

DS9041A/B-02 June 2012 www.richtek.com

Richtek Technology Corporation

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

Hsinchu, Taiwan, R.O.C.

Tel: (8863)5526789

Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should

obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot

assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be

accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third

parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.

Outline Dimension

AA1

SOT-23-6 Surface Mount Package

Dimensions In Millimeters Dimension s In Inches

Symbol Min Max Min Max

A 0.889 1.295 0.031 0.051

A1 0.000 0.152 0.000 0.006

B 1.397 1.803 0.055 0.071

b 0.250 0.560 0.010 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