A8425: High Current Photoflash Capacitor Charger with IGBT Driver for Two Li+ Batteries

Description

This part is discontinued. Samples are no longer available.

Date of status change: March 4, 2013.

Recommended Substitutions: For existing customer transition, and for new customers or new applications, contact Allegro Sales.

The A8425 charges photoflash capacitors for digital cameras, camcorders, and DSC combos. An integrated 55 V DMOS switch drives the transformer in a flyback topology optimized for 2-cell Li+ battery input. An integrated IGBT driver with separate source and sink pins allows high performance red-eye reduction implementation.

The A8425 offers programmable peak switch current limit from 1.0 to 3.2 A, continuously adjustable using a resistor to ground. A proprietary control scheme optimizes the capacitor charging time. Low quiescent current and low shutdown current further improve system efficiency and extend battery life.

The A8425 is available in 16-contact 3 mm × 3 mm TQFN packages. This small, very thin profile (0.75 mm nominal overall height) package is ideal for space-constrained applications. It is lead (Pb) free, with 100% matte-tin leadframe plating.

Applications include:

  • SLR camera flash
  • Digital camcorder/DSC combo flash
  • 2 Li+ input strobe

Top Features

  • Wide battery voltage range: 1.5 to 11 V
  • Integrated 55 V DMOS switch in very thin profile 3 mm × 3 mm, 0.75 mm nominal height package
  • Peak current limit continuously adjustable from 1.0 to 3.2 A
  • Output voltage sensing on primary side: no resistor divider required
  • >75% efficiency
  • Fast charge time
  • Charge Complete indication
  • Flexible, high current IGBT drive
  • Independent IGBT driver supply
  • Separate sink and source pins with 6 Ω pull-up and 20 Ω pull-down
  • Interlocked trigger pin improves noise immunity
  • No primary-side Schottky diode needed

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Compliant
Part Composition /
RoHS Data
Comments Samples Check Stock
A8425EESTR-T 16-lead QFN -40°C to 85°C Yes View Data Discontinued Contact your
local sales rep
Check
Distributor Stock

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Packaging

The A8425 is available in a 16-contact 3 mm × 3 mm MLP/TQFN (suffix ES) package. This small, low profile (0.75 mm) package is ideal for space-constrained applications. It is lead (Pb) free, with 100% matte-tin leadframe plating.

ES-QFN with exposed pad 16 contact