LT3420EMS#PBF

LT3420EMS#PBF charges high voltage photoflash capacitor quickly and efficiently. Designed for use in both digital and film cameras, this device uses 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. This device's output voltage sensing scheme monitors the flyback voltage to indirectly regulate the output voltage, eliminating an output resistor divider or discrete zener diode. This feature allows the capacitor to be held at a fully charged state without excessive power consumption. Automatic refresh allows the capacitor to remain charged while consuming an average input current of about 2mA, at a user-defined refresh rate. It is used in applications such as digital camera flash unit, film camera flash unit, high voltage power supplies etc.

• Charges 220µF to 320V in 3.7 seconds from 5V
• Charges any size photoflash capacitor
• Supports operation from two AA cells or any supply from 1.8V to 16V
• Uses standard transformers, efficient flyback operation (<gt/>75% typical)
• Adjustable output, automatic refresh
• Charge complete indicator
• No high voltage zener diode required, no output voltage divider required
• Controlled peak switch current is 1.4A
• Controlled input current is 840mA
• Operating ambient temperature range from -40°C to 85°C, package style is 10-lead plastic MSOP

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party