A8424: High Current Photoflash Capacitor Charger with IGBT Driver for 2 Li+ Batteries

Description

This device is no longer in production. The device should not be purchased for new design applications. Samples are no longer available.

Date of status change: December 10, 2012.

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

The A8424 charges photoflash capacitors for digital cameras, camcorders, and DSC combos. An integrated 55 V DMOS switch drives the transformer in a flyback topology, optimizing the design for 2-cell Li+ battery input. An integrated IGBT driver with separate source and sink pins allows high performance red-eye reduction implementation.

The A8424 offers a programmable peak switch current limit, from 0.5 to 1.5 A, user-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 A8424 is available in a 16-contact 3 mm × 3 mm TQFN package with exposed pad for enhanced thermal performance. 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
  • User-adjustable peak current limit, from 0.5 to 1.5 A
  • Output voltage sensing on primary side; no resistor divider required
  • >75% efficiency
  • Fast charging time
  • Charge complete indication
  • Flexible, high current IGBT driver
    • Independent IGBT driver supply
    • Separate sink and source pins with 6 Ω pull-up and 20 Ω pull-down
    • Interlocked trigger pins improve 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
A8424EESLU-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 A8424 is available in a 16-contact 3 mm × 3 mm MLP/TQFN 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