LT3420EMS

开关稳压器 LT3420 - Photoflash Capacitor Chargers with Automatic Refresh

DESCRIPTION

The LT®3420/LT3420-1 charge high voltage photoflash capacitors quickly and efficiently. Designed for use in both digital and film cameras, these devices use a flyback topology to achieve efficiencies up to four times better than competing flash modules. A unique adaptive off-time

control algorithm

.

maintains current-limited continuous mode transformer operation throughout the entire charge cycle, eliminating the high inrush current often found in modules.

FEATURES

■ Charges 220µF to 320V in 3.7 Seconds from 5V LT3420

■ Charges 100µF to 320V in 3.5 Seconds from 5V LT3420-1

■ Charges Any Size Photoflash Capacitor

■ Supports Operation from Two AA Cells or Any Supply from 1.8V to 16V

■ Controlled Peak Switch Current: 1.4A LT3420 1.0A LT3420-1

■ Controlled Input Current: 840mA LT3420 450mA LT3420-1

■ Uses Standard Transformers

■ Efficient Flyback Operation >75% Typical

■ Adjustable Output

■ Automatic Refresh

■ Charge Complete Indicator

■ No High Voltage Zener Diode Required

■ No Output Voltage Divider Required

■ Small 10-Lead MSOP Package

APPLICATION

■ Digital Camera Flash Unit

■ Film Camera Flash Unit

■ High Voltage Power Supplies