Richtek RT8009-10GJ5, RT8009-10PJ5, RT8009-12GB, RT8009-12GJ5, RT8009-12PB Schematic [ru]

1.25MHz, 600mA, High Efficiency PWM Step-Down
DC/DC Converter

RT8009

General Description

The RT8009 is a high-efficiency pulse-width-modulated

(PWM) step-down DC/DC converter. Capable of delivering

600mA output current over a wide input voltage range from

2.5 to 5.5V, the RT8009 is ideally suited for portable

electronic devices that are powered from 1-cell Li-ion

battery or from other power sources within the range such

as cellular phones, PDAs and handy-terminals.

Internal synchronous rectifier with low R

DS(ON)

dramatically

reduces conduction loss at PWM mode. No external

Schottky diode is required in practical application. The

RT8009 automatically turns off the synchronous rectifier

while the inductor current is low and enters discontinuous

PWM mode. This can increase efficiency at light load

condition.

The RT8009 enters Low-Dropout mode when normal PWM

cannot provide regulated output voltage by continuously

turning on the upper P-MOSFET. RT8009 enter shutdown

mode and consumes less than 0.1μA when EN pin is pulled

low.

The switching ripple is easily smoothed-out by small

package filtering elements due to a fixed operation

frequency of 1.25MHz. This along with small SOT-23-5

and TSOT-23-5 package provides small PCB area

application. Other features include soft start, lower internal

reference voltage with 2% accuracy, over temperature

protection, and over current protection.

Pin Configurations

(TOP VIEW)

LX

FB/VOUT

5

VIN

SOT-23-5/TSOT-23-5

4

23

GND EN

Marking Information

Features



2.5V to 5.5V Input Range







 Adjustable Output From 0.5V to V





 1.0V, 1.2V, 1.3V, 1.5V, 1.8V, 2.5V and 3.3V Fixed/



IN

Adjustable Output Voltage



 600mA Output Current





 95% Efficiency





 No Schottky Diode Required





 1.25MHz Fixed Frequency PWM Operation





 Small SOT-23-5 and TSOT-23-5 Package





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



Applications

 Cellular Telephones

 Personal Information Appliances

 Wireless and DSL Modems

 MP3 Players

 Portable Instruments

Ordering Information

RT8009(- )

Package Type
B : SOT-23-5
J5 : TSOT-23-5

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

Output Voltage
Default : Adjustable
10 : 1.0V
12 : 1.2V
13 : 1.3V
15 : 1.5V
18 : 1.8V
25 : 2.5V
33 : 3.3V

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.

For marking information, contact our sales representative

directly or through a Richtek distributor located in your

area.

DS8009-07 March 2011 www.richtek.com

1

RT8009

Typical Application Circuit

V

IN

2.5V to 5.5V

L

C

IN

4.7µF

1

3

VIN

EN

RT8009

VOUT

GND

2

LX

5

4

4.7µH

Figure 1. Fixed Voltage Regulator

V

C

OUT

10µF

OUT

Layout Guide

V

IN

C

IN

VIN

GND

EN

1

2

354

V

IN

2.5V to 5.5V

L

LX

VOUT

L

C

IN

4.7µF

1

3

VIN

RT8009

EN

GND

2

LX

FB

4.7µH

5

4

C1

Figure 2. Adjustable Voltage Regulator

C

V

OUT

GND

OUT

V

IN

VIN

C

IN

GND

EN

R1

R2

V

OUT

C

OUT

10µF

1

2

354

REF(Typ.)

L

LX

R2

FB

R1

C

REFOUT

=

OUT

0.5VV

⎛
⎜

⎝

V

OUT

GND

V

OUT

R1

⎞

1 x VV

+=

⎟

R2

⎠

and 1MR2R1 with

Ω≤+

Layout note:

1. The distance that C

2. C

should be placed near RT8009.

OUT

2

Figure 3

connects to VIN is as close as possible (Under 2mm).

IN

C1

DS8009-07 March 2011www.richtek.com

Functional Pin Description

Pin Number Pin Name Pin Function

1 VIN Power Input.

2 GND Ground.

3 EN Chip Enab le (Active H igh, do not leave EN pin floating, and VEN < VIN + 0. 6V).

4 FB/VOUT Feed back Inp ut P in.

5 LX Pin for Switching.

Function Block Diagram

RT8009

FB/VOUT

Slope

Compensation

Error

Amplifier

RC

COMP

EN

OSC &

Shutdown

Control

Current

Sense

PWM

Comparator

UVLO &

Power Good

Detector

V

REF

Current

Limit

Detector

Control

Logic

Zero

Detector

Driver

GND

VIN

RS1

LX

RS2

DS8009-07 March 2011 www.richtek.com

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RT8009

Absolute Maximum Ratings (Note 1)

 Supply Input Voltage ------------------------------------------------------------------------------------------------------ 6.5V

 Enable, FB Voltage ------------------------------------------------------------------------------------------------------- V

 Power Dissipation, P

@ TA = 25°C

D

SOT-23-5, TSOT-23-5 ----------------------------------------------------------------------------------------------------- 0.4W

 Package Thermal Resistance (Note 2)

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

SOT-23-5, TSOT-23-5, θJC----------------------------------------------------------------------------------------------- 130°C/W

 Junction Temperature Range -------------------------------------------------------------------------------------------- 150°C

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

 Storage Temperature Range -------------------------------------------------------------------------------------------- −65°C to 150°C

 ESD Susceptibility (Note 3)

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

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

Recommended Operating Conditions (Note 4)

 Supply Input Voltage ------------------------------------------------------------------------------------------------------ 2.5V to 5.5V

 Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C

 Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C

+ 0.6V

IN

Electrical Characteristics

(V

= 3.6V, V

IN

Input Voltage Range

Quiescent Current

Shutdown Cur rent

Reference Voltage

Adjustable Output Range

Output Voltage
Accuracy

OUT

= 2.5V, V

= 0.5V, L = 4.7μH, C

REF

Parameter Symbol Test Conditions Min Typ Max Unit

V

IN

I

I

Q

I

SHDN

V

REF

V

OUT

ΔV

OUT

ΔV

OUT

ΔV

OUT

ΔV

OUT

Fix

ΔV

OUT

ΔV

OUT

ΔV

OUT

ΔV

OUT

= 4.7μF, C

IN

OUT

= 10μF, T

= 25°C, I

A

= 600mA unless otherwise specified)

MAX

2.5 -- 5.5 V

= 0mA, VFB = V

OUT

EN = GND -- 0.1 1 μA

For adjustable output voltage 0.49 0.5 0.51 V

= 2. 5 to 5. 5V , V

V

IN

0A < I
V

IN

0A < I
V

IN

0A < I
V

IN

0A < I
V

IN

0A < I

V

IN

V

OUT

V

IN

V

OUT

V

IN

0A < I

< 600mA

OUT

= 2. 5 to 5. 5V , V

< 600mA

OUT

= 2. 5 to 5. 5V , V

< 600mA

OUT

= 2. 5 to 5. 5V , V

< 600mA

OUT

= 2. 5 to 5. 5V , V

< 600mA

OUT

= V

+ ΔV to 5.5V (Note 5)

OUT

= 2.5V, 0A < I

= V

+ ΔV to 5.5V (Note 5)

OUT

= 3.3V, 0A < I

= V

+ 0.2V to 5.5V

OUT

< 600mA

OUT

+ 5%

REF

= 1.0V

OUT

= 1.2V

OUT

= 1.3V

OUT

= 1.5V

OUT

= 1.8V

OUT

< 600mA

OU T

< 600mA

OU T

-- 50 100

V

REF

--

V

− 0.2

IN

−3 -- 3 %

−3

−3

−3

−3

−3

−3

−3

-- 3 %

-- 3 %

-- 3 %

-- 3 %

-- 3 %

-- 3 %

-- 3 %

To be continued

μA

V

DS8009-07 March 2011www.richtek.com

4

RT8009

Parameter Symbol Test Conditions Min Typ Max Unit

Output Voltage
Accuracy

Adjustable

FB Input Current

R

R

of P- Channel MO SFET R

DS(ON)

of N-Channel MOSFET R

DS(ON)

P-Channel Current Limit

EN High-Level Input Voltage

EN Low-Level Input Voltage

ΔV

OU T

I

V

FB

DS(ON)_P

DS(ON)_N

I

LIM_P

V

EN_H

V

EN_L

V

I

I

V

= V

IN

0A < I

= VIN −50

FB

OUT

OUT

= 2.5V to 5.5 V

IN

+ ΔV to 5.5V (Note 5)

OUT

< 600mA

OUT

= 200mA

= 200mA

VIN = 2.5V to 5.5V

VIN = 2.5V to 5.5V

V

IN

V

IN

V

IN

V

IN

= 3.6V

= 2.5V

= 3.6V

= 2.5V

−3

-- 3 %

-- 50 nA

-- 0.3 0.65

Ω

-- 0.4 0.80

-- 0.25 0.55

Ω

-- 0.35 0.65

1 -- 1.8 A

1.5 -- -- V

-- -- 0.4 V

Under Voltage Lockout Threshold -- 1.8 -- V

Hysteresis -- 0.1 -- V

Oscillator Frequency

Thermal Shutdown Temperature

f

V

OSC

T

SD

= 3.6V, I

IN

OUT

= 100mA

-- 160 -- °C

0.8 1.25 1.85 MHz

Min. On Time -- 50 -- ns

Max. Duty Cycle 100 -- -- %

LX Leakage Current

V

IN

= 3.6V, V

= 0V or V

LX

= 3.6V −1

LX

-- 1

μA

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 recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Note 5. ΔV = I

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.

x R

OUT

DS(ON)_P

DS8009-07 March 2011 www.richtek.com

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