Richtek RT8010BGQW Schematic [ru]

RT8010B

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DS8010B-04 March 2011 www.richtek.com

Features

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 2.5V to 4V Input Range

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 Output Voltage (Adjustable Output From 0.6V to V

IN

)

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 800mA Output Current

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 95% Efficiency

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 No Schottky Diode Required

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 1.5MHz Fixed Frequency PWM Operation

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 Small 8-Lead WDFN Package

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 RoHS Compliant and Halogen Free

Applications

 Mobile Phones

 Personal Information Appliances

 Wireless and DSL Modems

 MP3 Players

 Portable Instruments

1.5MHz, 800mA, High Efficiency PWM

Step-Down DC/DC Converter

General Description

The RT8010B is a high-efficiency Pulse-Width-Modulated

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

800mA output current over a wide input voltage range from

2.5V to 4V, the RT8010B is ideally suited for portable

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

battery or from other power sources such as cellular

phones, PDAs and hand-held devices.

Two operating modes are available including PWM/Low-

Dropout autoswitch and shut-down modes. The 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 RT8010B enters Low-Dropout mode when normal

PWM can not provide regulated output voltage by

continuously turning on the upper PMOS. The RT8010B

enters shut-down 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 operating

frequency of 1.5MHz. This along with small WDFN-8L 2x2

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.

Marking Information

For marking information, contact our sales representative

directly or through a Richtek distributor located in your

area.

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.

Pin Configurations

(TOP VIEW)

WDFN-8L 2x2

EN

FB

PGND

PGND

PGND

VIN

LX

AGND

7

6

5

1

2

3

4

8

9

RT8010B

Package Type

QW : WDFN-8L 2x2 (W-Type)

Lead Plating System

G : Green (Halogen Free and Pb Free)

RT8010B

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DS8010B-04 March 2011www.richtek.com

Function Block Diagram

Functional Pin Description

Pin No. Pin Name Pin Function

1 EN Ch ip Ena ble (Active H igh ).

2 FB Feedback Pin.

3 VIN Power Input.

4 LX Pin for Switching.

5 AGND Analog Ground.

6, 7, 8 PGND Power Ground.

9 (Exposed Pad) NC No Internal Connection.

Typical Application Circuit

⎟

⎠

⎞

⎜

⎝

⎛

+=

R2

R1

1 x VV

REFOUT

with R2 = 75kΩ to 200kΩ,

and (R1 x C1) should be in the range between 3x10

-6

and 6x10

-6

for component selection.

4.7µF

10µF

VIN

LX

RT8010B

EN

FB

2.2µH

2.5V to 4V

V

IN

V

OUT

C

IN

L

2

4

3

1

C

OUT

R1

R2

C1

I

R2

PGND

5

AGND

6, 7, 8

COMP

RC

RS1

RS2

EN VIN

LX

FB

UVLO &

Power Good

Detector

V

REF

Slope

Compensation

Current

Sense

OSC &

Shutdown

Control

Current

Limit

Detector

Driver

Control

Logic

PWM

Comparator

Error

Amplifier

PGND

AGND

RT8010B

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DS8010B-04 March 2011 www.richtek.com

Absolute Maximum Ratings (Note 1)

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

 EN, FB Pin Voltage ------------------------------------------------------------------------------------------------------- −0.3V to V

IN

 Power Dissipation, P

D

@ T

A

= 25°C

WDFN-8L 2x2 -------------------------------------------------------------------------------------------------------------- 0.606W

 Package Thermal Resistance (Note 2)

WDFN-8L 2x2, θ

JA

--------------------------------------------------------------------------------------------------------- 165°C/W

WDFN-8L 2x2, θ

JC

-------------------------------------------------------------------------------------------------------- 20°C/W

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

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

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

 ESD Susceptibility (Note 3)

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

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

Electrical Characteristics

(V

IN

= 3.6V, V

OUT

= 2.5V, V

REF

= 0.6V, L = 2.2μH, C

IN

= 4.7μF, C

OUT

= 10μF, I

MAX

= 0.8A, T

A

= 25°C, unless otherwise specified)

Parameter Symbol Test Conditions Min Typ Max Unit

Input Voltage Range

V

IN

2.5 -- 4 V

Quiescent Current I

Q

I

OUT

= 0mA, V

FB

= V

REF

+ 5% -- 50 70 μA

Shutdown Current

I

SH DN

EN = GND -- 0.1 1

μA

Reference Voltage

V

REF

For Adjustable Output Voltage 0.588 0.6 0.612 V

Adjustable Output Range

V

OUT

(Note 6)

V

REF

--

V

IN

− 0.2V

V

Output Voltage

Accuracy

Adjustable

ΔV

OUT

V

IN

= V

OUT

+ ΔV to 4V (Note 5)

0A < I

OUT

< 0.8A

−3

-- +3 %

FB Input Current

I

FB

V

FB

= V

IN

−50 -- 50 nA

V

IN

= 3.6V

-- 0.28 --

Ω

P-MOSFET R

ON

R

DS(ON)_P

I

OU T

= 200mA

V

IN

= 2.5V -- 0.38 --

V

IN

= 3.6V

-- 0.25 --

Ω

N-MOSFET R

ON

R

DS(ON)_N

I

OU T

= 200mA

V

IN

= 2.5V

-- 0.35 --

P-Channel Current Limit I

LIM_P

V

IN

= 2.5V to 4V 1.2 1.5 -- A

EN High-Level Input Voltage

V

EN_H

V

IN

= 2.5V to 4V

1.5 -- -- V

EN Low-Level Input Voltage

V

EN_L

V

IN

= 2.5V to 4V

-- -- 0.4 V

Under Voltage Lockout

Threshold

UVLO -- 1.8 -- V

Hysteresis -- 0.1 -- V

To be continued

Recommended Operating Conditions (Note 4)

 Supply Input Voltage------------------------------------------------------------------------------------------------------ 2.5V to 4V

 Junction Temperature Range--------------------------------------------------------------------------------------------

−40°C to 125°C

 Ambient Temperature Range--------------------------------------------------------------------------------------------

−40°C to 85°C

RT8010B

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DS8010B-04 March 2011www.richtek.com

Parameter Symbol Test Condit ions Min Typ Max Unit

Oscillator Frequency

f

OSC

V

IN

= 3.6V, I

OU T

= 100mA

1.2 1.5 1.8 MHz

Thermal Shutdown Temperature

T

SD

-- 160 --

°C

Max. Duty Cycle 100 -- -- %

LX Leakage Current

V

IN

= 3.6V, V

LX

= 0V or V

LX

= 3.6V −1

-- 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

JA

is measured in the natural convection at T

A

= 25°C on a high effective four layers thermal conductivity test board of

JEDEC 51-7 thermal measurement standard. The case point of θ

JC

is on the expose pad of the package.

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. ΔV = I

OUT

x P

RDS(ON)

Note 6. Guarantee by design.