Description

The A8439 is a highly integrated IC that charges photoflash capacitors for digital and film cameras. An integrated MOSFET switch drives the transformer in a flyback topology. It also features an integrated IGBT driver that facilitates the flash discharge function and saves board space.

The CHARGE pin enables the A8439 and starts the charging of the output capacitor. When the designated output voltage is reached, the A8439 stops the charging until the CHARGE pin is toggled again, or when output voltage falls below 90 of the designated value. Pulling the CHARGE pin low stops the charging. The DONE pin is an open-drain indicator of when the designated output voltage is reached.

Features and Benefits

▪ Power with 1 Li+ or 2 Alkaline/NiMH/NiCAD batteries

▪ Adjustable output voltage

▪ Auto-refresh

▪ >75 efficiency

▪ Eight-level, digitally-programmable current limit

▪ Charge complete indication

▪ Integrated IGBT driver with trigger

▪ No primary-side Schottky diode needed

▪ Low-profile package (0.75 mm nominal height)

Applications include the following:

▪ Digital camera flash

▪ Film camera flash

▪ Cell phone flash

▪ Emergency strobe light