Using the LT3420 photoflash capacitor recharger IC from Linear Technology you get a high-efficiency, low-quiescent-current device that is designed to do one thing only: manage the charger of the high-voltage capacitor used for camera flash modules. This IC, which functions as a standalone device, offloads your camera processor and software from this critical task. It uses a flyback topology to charge the capacitor, and can bring a 220 µF cap to 320V potential in under 3.7 seconds, operating | 
The LT3420 IC uses a flyback design and internal adaptive algorithm for high performance while offloading the camera's internal CPU. |
from a 5-V supply. Efficiency is over 75%, and peak current is 1.4A. Within the IC is an adaptive algorithm that maintains proper current limiting of the operation, to prevent the high inrush current normally associated with flash modules. The LT3420 monitors the flyback voltage to indirectly regulate the output voltage, thus eliminating the need for an external resistive divider or Zener diode. The MSOP-10 IC is US$2.50 in 1000-piece lots
Linear Technology CorpFax (65) 754-4113
www.linear.com
