The Allegro® A8738 Xenon photoflash charger IC is designed to meet the needs of ultra-low power, small form factor cameras, particularly camera-phones.
This device integrates a fixed regulator to precisely control the IGBT flash current across a wide range of battery voltages, providing a 3 V, gate drive. The IGBT driver also has separate source and sink connections, for flexibility in controlling IGBT rise and fall times.
The charge current time is adjustable by setting the charge current limit from 0.4 to 0.9 A maximum. By using primary-side voltage sensing, the 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 A8738 features very low supply current draw, typically 0.5 µA maximum in shutdown mode.
The charge and trigger voltage logic thresholds are set at 1.1 V (VIH(min)) to support applications implementing low voltage control logic.
The device is available in a 10-contact, 3 mm × 3 mm TDFN package with exposed pad for enhanced thermal performance. It is lead (Pb) free, with 100% matte-tin leadframe plating.
Applications
- Mobile phone flash
- Digital and film camera flash