
Allegro MicroSystems
Description
The A8438 is a highly integrated IC that charges photoflash capacitors for digital and film cameras. It also features an integrated IGBT driver that facilitates the flash discharge function and saves board space.
To charge the photoflash capacitor, the A8438 integrates a 40 V, DMOS switch that drives the transformer in a flyback topology, allowing optimized design with tight coupling and high efficiency. A proprietary control scheme optimizes the capacitor charging time. Low quiescent current and low shutdown current further improve system efficiency and extend battery life.
FEATUREs and Benefits
▪ Power with 1 Li+ or 2 Alkaline/NiMH/NiCAD batteries
▪ Adjustable output voltage
▪ >75% efficiency
▪ Three levels of switch current limit: 1.6, 1.8, 2.0 A
▪ Fast charge time
▪ Charge complete indication
▪ Integrated IGBT driver with trigger
▪ No primary-side Schottky diode needed
▪ Low-profile package (0.75 mm nominal height)
APPLICATIONs include:
▪ Digital camera flash
▪ Film camera flash
▪ Cell phone flash
▪ Emergency strobe light