Linear Technology Corp. (LTC, Milpitas, CA) announced its LT3468, a high-efficiency, fast photoflash capacitor charger. The LT3468 charges high-voltage (typically 320V) photoflash capacitors and is intended for use in both digital and film cameras. The device uses a current-limited flyback topology and can charge a 100µF capacitor to 320V in 4.6 seconds from a 3.6V battery.
With a controlled peak current of 1.4A, the LT3468 in conjunction with a standard flyback transformer, can charge any size photoflash capacitor with efficiencies greater than 80%. The LT3468-1 is identical to the LT3468 except that the current limit has been reduced to 0.7A from 1.4A. The reduced input current is needed for smaller batteries in applications such as cellular phone cameras. Both the LT3468 and LT3468-1 utilize primary-side, output-voltage detection internal to the device, eliminating the need for a resistor divider or discrete zener diodes and their power losses.
The LT3468 and LT3468-1 are available from stock and are priced at $1.95 each in 1,000-piece quantities.
