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

Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.

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