Description

to meet the needs of ultra low power, small form factor cameras,

particularly camera phones. By using primary-side voltage

sensing, the need for a secondary-side resistive voltage divider

is eliminated.This has the additional benefit of reducing leakage

currents on the secondary side of the transformer. To extend

battery life, the A8732 features very low supply current draw

(0.5 μA max in shutdown mode). The switch current limit can

be programmed from 0.45 to 1.5 A, in 16 steps with single wire

interface, through the CHARGE pin.

The IGBT driver also has internal gate resistors for minimum

external component count. The charge and trigger voltage

implementing low-voltage control logic.

The A8732 is available in an 8-contact 2 mm × 2 mm

DFN/MLP package with a 0.60 maximum overall package

height, and an exposed pad for enhanced thermal performance.

It is lead (Pb) free with 100% matte tin leadframe plating.

8732-DS

Features and Benefits

▪ Ultra small 2 × 2 DFN/MLP-8 package

▪ Low quiescent current draw (0.5 μA max. in shutdown mode)

▪ Primary-side output voltage sensing; no resistor divider required

▪ Adjustable switch peak current limit up to 1.5 A with

single-wire programming through the CHARGE pin

▪ Integrated IGBT driver with internal gate resistors

▪ Optimized for mobile phone, 1-cell Li+ battery applications

▪ Zero-voltage switching for lower loss

▪ >75% efficiency

▪ Charge complete indication

▪ Integrated 50 V DMOS switch with self-clamping

protection

Ultra Small Mobile Phone Xenon Photoflash

Capacitor Charger with IGBT Driver

Package: 8-pin DFN/MLP (suffix EE)

Typical Applications

Not to scale

A8732

2 mm × 2 mm, 0.60 mm height

+

SW

VBAT

VIN_VDRV

Control

Block

CHARGE

VIN_VDRV

DONE

GND

TRIG

VPULLUP

VOUT Detect

DONE

Battery Input

1.5 to 5.5 V

C2

100

F

315 V

C1

100 kΩ

IGBT Gate

GATE

IGBT Driver

Figure 1. Typical applications: (A) with single battery supply and (B) with separate bias supply

(A)

(B)

+

SW

VBAT

VIN_VDRV

Control

Block

CHARGE

VIN_VDRV

DONE

GND

TRIG

VPULLUP

VOUT Detect

DONE

Battery Input

2.3 to 5.5 V

C2

100

F

315 V

C1

100 kΩ

IGBT Gate

GATE

IGBT Driver