A8740: Ultra Small Mobile Phone Xenon Photoflash Capacitor Charger with IGBT Driver

Description

DISCONTINUED PART: This part is no longer in production. Samples are no longer available.

Date of status change: August 27, 2012.

The Allegro® A8740 is a Xenon photoflash charger IC designed to meet the needs of ultra low power, small form factor cameras, particularly camera phones. By using primary-side voltage sensing, the need for a secondary-side resistive voltage divider is eliminated. This has the additional benefit of reducing leakage currents on the secondary side of the transformer. To extend battery life, the A8740 features very low supply current draw (0.5 µA max in shutdown mode). The IGBT driver also has internal gate resistors for minimum external component count. The charge and trigger voltage logic thresholds are set at 1.3 VHI(min) to support applications implementing lowvoltage control logic.

The A8740 is available in an 8-contact 2 mm × 2 mm DFN/MLP package with a 0.60 maximum overall package height, and an exposed pad for enhanced thermal performance. It is lead (Pb) free with 100% matte tin leadframe plating.

Top Features

  • Ultra small 2 × 2 DFN/MLP-8 package
  • Low quiescent current draw (0.5 µA max. in shutdown mode)
  • Primary-side output voltage sensing; no resistor divider required
  • Fixed 1.5 A peak current limit
  • 1.3 V logic (VHI(min)) compatibility
  • Integrated IGBT driver with internal gate resistors
  • Optimized for mobile phone, 1-cell Li+ battery applications
  • Zero-voltage switching for lower loss
  • >75% efficiency
  • Charge complete indication
  • Integrated 50 V DMOS switch with self-clamping protection

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Compliant
Part Composition /
RoHS Data
Comments Samples Check Stock
A8740EEETR-T 8-lead DFN -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 A8740 is available in an 8-contact 2 mm × 2 mm DFN/MLP package (suffix EE) with a 0.60 maximum overall package height, and an exposed pad for enhanced thermal performance. It is lead (Pb) free with 100% matte tin leadframe plating.

EE-DFN 8 lead with exposed pad