Description

The A8426 is a highly integrated IC that rapidly charges photoflash capacitors for SLR cameras, digital cameras, and camcorders with integrated digital cameras. A flexible IGBT driver is integrated to save board space.

The A8426 integrates a 3.2 A-capable, 55 V-rated DMOS switch that drives the transformer in flyback configuration, allowing optimized design with tight coupling and high efficiency. The peak switch current is user-adjustable between 1 and 3.2 A, using a resistor to ground. A proprietary control scheme optimizes the capacitor charging time. Low quiescent current and low-power Standby mode current further improve system efficiency and extend battery life.

Features and Benefits

▪ Wide battery voltage range: 1.5 to 11 V

▪ Integrated 55 V DMOS switch with 3.2 A current capability

▪ User-adjustable peak current limit, from 1 to 3.2 A

▪ Secondary-side voltage sensing for easily-adjustable

output voltage

▪ >75 efficiency

▪ Fast charging time

▪ Charge complete indication

▪ Flexible, high current IGBT driver

▫ Independent IGBT driver supply

▫ Separate sink and source pins with 6 Ω pull-up and

20 Ω pull-down

▫ Interlocked trigger pins improve noise immunity

▪ No primary-side Schottky diode needed

Applications include:

▪ SLR camera flash

▪ Digital camcorder/DSC combo flash

▪ 2 Li+ input strobe