DESCRIPTION
The LT®3468/LT3468-1/LT3468-2 are highly integrated ICs designed to charge photoflash capacitors in digital and film cameras. A patented control technique* allows for the use of extremely small transformers. Each device contains an on-chip high voltage NPN power switch. Output voltage detection is completely contained within the device, eliminating the need for any discrete zener diodes or resistors. The output voltage can be adjusted by simply changing the turns ratio of the transformer. The LT3468 has a primary current limit of 1.4A, the LT3468-2 has a 1A limit, and the LT3468-1 has a 0.7A limit. These different current limit levels result in well controlled input currents of 500mA for the LT3468, 375mA for the LT3468-2 and 225mA for the LT3468-1. Aside from the differing current limit, the three devices are otherwise equivalent.

FEATURES
■ Highly Integrated IC Reduces Solution Size
■ Uses Small Transformers: 5.8mm × 5.8mm × 3mm
■ Fast Photoflash Charge Times:
   4.6s for LT3468 (0V to 320V, 100µF, VIN = 3.6V)
   5.7s for LT3468-2 (0V to 320V, 100µF, VIN = 3.6V)
   5.5s for LT3468-1 (0V to 320V, 50µF, VIN = 3.6V)
■ Controlled Input Current:
   500mA (LT3468)
   375mA (LT3468-2)
   225mA (LT3468-1)
■ Supports Operation from Single Li-Ion Cell, or Any Supply from 2.5V up to 16V
■ Adjustable Output Voltage
■ No Output Voltage Divider Needed
■ Charges Any Size Photoflash Capacitor
■ Low Profile (<1mm) SOT-23 Package

APPLICATIONS
■ Digital / Film Camera Flash
■ PDA / Cell Phone Flash
■ Emergency Strobe