Richtek RT9179GB, RT9179PB Schematic [ru]

Adjustable, 300mA LDO Regulator with Enable

RT9179

General Description

The RT9179 is a high performance linear voltage regulator

with enable high function and adjustable output with a

1.175V reference voltage. It operates from an input of 3V

to 5.5V and provides output current up to 300mA with two

external resistors to set the output voltage ranges from

1.175V to 4.5V.

The RT9179 has superior regulation over variations in line

and load. Also it provides fast respond to step changes in

load. Other features include over-current and over-

temperature protection. The device has enable pin to reduce

power consumption in shutdown mode.

The devices is available in the popular SOT-23-5 package.

Ordering Information

RT9179

Package Type
B : SOT-23-5

Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)

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.

Features

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300mV Dropout @ 300mA

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z 150uA Low Ground Pin Current

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z Excellent Line and Load Regulation

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z <1uA Standby Current in Shutdown Mode

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z Guaranteed 300mA Output Current

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z Stable with 1uF Input a nd Output Cera mic Ca pacitor

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z Adjustable Output V oltage Ra nges from 1.175V to

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4.5V

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z Over-T emperature/Over-Current Protection

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z RoHS Compliant and 100% Lead (Pb)-Free

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Applications

z Battery-Powered Equipment

z Graphic Card

z Peripheral Cards

z PCMCIA Card

Marking Information

For marking information, contact our sales representative

directly or through a Richtek distributor located in your

area.

Pin Configurations

(TOP VIEW)

VOUT

5

VIN

ADJ

23

EN

GND

4

SOT-23-5

DS9179-11 April 2011 www.richtek.com

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RT9179

Typical Application Circuit

V

IN

Chip Enable

C

C

3

0.1uF

Note: The external feedback resistors are in hundreds of OHM to hundreds of kOHM ranges.

1

1uF

V

= 1.175 x ( ) Volts

OUT

RT9179

ADJ

GND

R

1+

R

VOUT

1

2

VIN

EN

Adjustable Operation

Functional Pin Description

Pin No. Pin Name Pin Function

1 VIN Power Input Voltage

2 GND Ground

3 EN Chip Enable (Active High)

Adjust Output Voltage. The output voltage is set by the internal feedback resistors when

4 ADJ

this pin grounded. If external feedback resistors are applied, the output voltage will be:

R

V

= 1.175 × (1 + ) Volts

OUT

1

2

R

V

OUT

R

1

C

2

R

1uF

2

5 VOUT Output Voltage

Function Block Diagram

EN

Shutdown

Logic Control

1.175V
V

REF

and

+

_

Error

Amplifier

Current-Limit

and

Thermal Protection

MOS

Driver

VIN

Thermal

SHDN

VOUT

ADJ

GND

DS9179-11 April 2011www.richtek.com

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RT9179

Absolute Maximum Ratings (Note 1)

z Supply Input Voltage ------------------------------------------------------------------------------------------------ 6V

z Power Dissipation, P

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

z Package Thermal Resistance (Note 2)

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

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

z Junction Temperature ----------------------------------------------------------------------------------------------- 150°C
z Storage Temperature Range --------------------------------------------------------------------------------------- −65°C to 150°C

z ESD Susceptibility (Note 3)

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

MM (Machine Mode) ------------------------------------------------------------------------------------------------ 200V

Recommended Operating Conditions (Note 4)

z Supply Input Voltage ------------------------------------------------------------------------------------------------ 3V to 5.5V

z Enable Input Voltage ------------------------------------------------------------------------------------------------ 0V to 5.5V
z Junction Temperature Range -------------------------------------------------------------------------------------- −40°Cto 125°C

@ TA = 25°C

D

Electrical Characteristics

(V

= V

IN

+ 0.7V, I

OUT

Parameter Symbol Test Conditions Min Typ Max Unit

Reference Voltage Tolerance V

Adjust Pin Current I

Output Voltage Range V

Quiescent Current (Note 5) IQ Enabled, I

Standby Current (Note 6) I

Current Limit I

Dropout Voltage (Note 7) V

Line Regulation ΔV

Thermal Shutdown Temperature TSD -- 170 -- °C

Thermal Shutdown Hysteresis ΔTSD -- 40 -- °C

EN Threshold

EN Current IEN V

= 10uA, C

OUT

Logic-Low Voltage VIL V

Logic-High Voltage V

= C

IN

= 1uF (Ceramic), T

OUT

1.163 1.175 1.187 V

REF

-- -- 10 nA

ADJ

1.175 -- 4.5 V

OUT

VIN = 5.5V, Shutdown -- -- 1 μA

STBY

0.5 -- -- A

LIM

DROP

V

LINE

V

IH

= 25°C unless otherwise specified)

A

I

= 10mA -- 10 --

OUT

= 300mA -- 300 -

I

OUT

+ 0.7V < VIN < 5.5V -- 0.001 -- %/V

OU T

= 3.3V, Shutdown -- -- 0.4

IN

= 3.3V, Enable 2.0 -- --

IN

= 5.5V, Enable -- -- 10 nA

IN

= 0mA -- 150 -- μA

OUT

mV

V

DS9179-11 April 2011 www.richtek.com

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RT9179

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. θ

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. Quiescent, or ground current, is the difference between input and output currents. It is defined by I

Note 6. Standby current is the input current drawn by a regulator when the output voltage is disabled by a shutdown signal

(V

Note 7. The dropout voltage is defined as V

is measured in the natural convection at TA = 25°C on a low effective thermal conductivity test board of

JA

JEDEC 51-3 thermal measurement standard.

= IIN - I

Q

no load condition (I

= 0mA). The total current drawn from the supply is the sum of the load current plus the ground

OUT

pin current.

0.4V). It is measured with V

EN

≤

= 5.5V.

IN

IN

-V

, which is measured when V

OUT

OUT

is V

OUT(NORMAL)

− 100mV.

OUT

under

DS9179-11 April 2011www.richtek.com

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