SM8150AB 参数 Datasheet PDF下载

SM8150A

PMIC with White LED Driver

1. OVERVIEW

The SM8150A is a charge pump type white LED driver, with 2-system programmable LDOs (Low Dropout

Regulator), and step-down DC/DC converter power management IC. The white LED driver provides constant-

current drive for 1 to 6 backlight white LED connected in parallel and 1 torch/strobe white LED. The charge

pump automatically selects between

×

1 mode,

×

1.5 boost mode, and

×

2 boost mode in response to battery volt-

age, LED drive current, and VF

LED

(LED forward bias voltage drop) conditions in order to extend battery

drive life. The SM8150A operating mode settings are accessed using an I

2

C

*1

interface, allowing LED drive

current, LDO voltage, output ON/OFF, and other settings to be controlled from a microcontroller.

*1. I

2

C-BUS is a registered trademark of NXP B. V.

2. FEATURES

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3. TYPICAL APPLICATION CIRCUIT

1µF

1µF

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Optimum specifications for clamshell cellular

phone with camera

• LCD backlight: Main-4ch/Sub-2ch (max 25mA/ch)

• Camera flash: 1ch (max 300mA)

Power saving design by automatic mode selection

of charge pump

• Power at

×

1.5 mode is reduced by 25% from

×

2 mode

• Power at

×

1 mode is reduced by 50% from

×

2

mode, 33% from

×

1.5 mode

2

I C interface best match for cellular phone chipset

Selecting current value (torch/strobe) of flash LED

by SBN pin

Shutdown synchronized to microcontroller supply

by VEN pin

1 system of step-down DC/DC converter built-in

• Output: 1.2 to 3.0V@ max 500mA

2 systems of programmable LDO built-in

• Output: 1.5/1.8/2.5/2.6/2.8/3.0/3.1/3.3V@ max 300mA

Various protection circuits built-in

• Startup soft start circuit built-in

• Overtemperature thermal shutdown (TSD) cir-

cuit built-in

• Supply undervoltage lockout (UVLO) circuit built-in

Supply voltage range (VIN1 to VIN3): 2.7 to 4.6V

Logic operating voltage range (VEN) : 1.8 to 4.6V

White LED Driver

• Charge-pump frequency: 1.0MHz (typ)

• Charge-pump maximum output current: 450mA

• Backlight LED current: 25

±

1.5mA/ch (max)

• Backlight LED relative accuracy:

±

3%

• Flash LED current: 300

±

20mA (max)

DC/DC converter

• DC/DC converter output voltage: 1.2 to 3.0V (typ)

• DC/DC converter output current: 500mA (max)

• DC/DC converter operating frequency: 2.0MHz (typ)

• DC/DC converter voltage accuracy:

±

2%

LDO

• LDO output voltage: 1.5 to 3.3V (VIN = 3.6V)

• LDO output current: 300mA (max)

• LDO dropout voltage: 0.1V (typ)

• LDO voltage accuracy:

±

2%

Package: 28-pin QFN

3.6V

C1P

VIN1

4.7µF

PGND1

VIN2

2.2µF

PGND2

DIN2

VIN3

2.2µF

DIN3

DIN4

DIN5

DIN6

Logic supply

VEN

0.1µF

DIN1

C1M C2P

C2M

VOUT

2.2µF

SM8150A

DIN7

I

2

C

SCL

SDA

LDOUT1

2.2µF

LDOUT2

2.2µF

LDO1 output

LDO2 output

Strobe

ON/OFF

SBN

100kΩ

FB

8pF

VREF

LX

2.2µH

GND1

GND2

2.2µF

DCOUT

(1.8V)

200kΩ

0.1µF

4. APPLICATIONS

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Cellular phone

Mobile equipment

5. ORDERING INFORMATION

Device

SM8150AB

Package

28-pin QFN

SEIKO NPC CORPORATION —1