The Allegro® A8437 Xenon photoflash charger IC is designed to meet the needs of ultra-low power, small form factor cameras, particularly camera-phones.
The charge current time is adjustable by setting the charge current limit from 0.4 to 1.2 A maximum. By using primaryside 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 A8437 features very low supply current draw—typically 0.1 µA in shutdown mode and 10 µA in standby mode.
The A8437 has a flash dual trigger IGBT driver and flash interlock to increase the device noise immunity. The IGBT driver also has separate source and sink connections, for flexibility in controlling IGBT rise and fall times. The charge and trigger voltage logic thresholds are set at 1.1 VHI(min) to support applications implementing low voltage control logic.
The A8437 is available in a 10-pin 3 mm × 3 mm DFN/MLP package with exposed pad for enhanced thermal performance. For an even smaller PCB footprint, a wafer-level chip scale package (WLCSP) option is available.