AS3685A/AS3685B

austriami crosyst ems

Product Brief

www.austriamicrosystems.com (ptr)

Revision 2.0 / 20060726

1 - 2

1

General Description

The AS3685 is low noise high efficiency capacitive

charge pump with 1:1, 1:1.5 and 1:2 operating

modes in a small 3x3mm DFN10 or a tiny 2x1.5mm

WL-CSP

(Wafer

Level

Chip

Scale

Package)

package. It can drive one flash led at up to 700mA

current. It supports flash/torch and indicator mode

for the flash led.

Additionally the AS3685 limits the flash time

automatically to protect the flash LED.

2

Key Features

High Efficiency capactive charge pump with 1:1,

1:1.5 and 1:2 modes

−

1:2 Mode can be disabled

(factory programmable)

Up to 700mA Led Current

Automatic Charge Pump Mode switching (Up)

LED cathode disconnect in Shutdown

Overtemperature Protection

Automatic 800ms Flash Timeout to protect the

flash LED (time factory programmable)

Two Device Variants:

−

AS3685A: Direct control to select three

currents

−

AS3685B: Single Pin Interface or Two Pin

Interface with Strobe Input; 17 different

currents can be selected

Package

−

DFN10 3x3mm (10 pins + exposed pad)

−

WL-CSP (Wafer Level Chip Scale Package)

3x4 balls 0.5mm pitch (2x1.5mm)

3

Application

Flash / Torch for Mobile Phones, Digital

Cameras and PDA

4

Application Diagram

Figure 1 – Application Diagram of AS3685A/AS3685B

C1+ C1- C2+ C2-

VCP

ILED

AS3685A

AS3685B

ISET

VBAT

EN1

EN2

2.2 F

2.2 F

VSS

Product Brief

AS3685A/AS3685B

Ultra Small High Efficiency 700mA Charge Pump for White LED Flash