A8738: Fixed Gate Drive Xenon Photoflash Charger


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 Allegro® A8738 Xenon photoflash charger IC is designed to meet the needs of ultra-low power, small form factor cameras, particularly camera-phones.

This device integrates a fixed regulator to precisely control the IGBT flash current across a wide range of battery voltages, providing a 3 V, gate drive. The IGBT driver also has separate source and sink connections, for flexibility in controlling IGBT rise and fall times.

The charge current time is adjustable by setting the charge current limit from 0.4 to 0.9 A maximum. By using primary-side voltage sensing, the 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 A8738 features very low supply current draw, typically 0.5 µA maximum in shutdown mode.

The charge and trigger voltage logic thresholds are set at 1.1 V (VIH(min)) to support applications implementing low voltage control logic.

The device is available in a 10-contact, 3 mm × 3 mm TDFN package with exposed pad for enhanced thermal performance. It is lead (Pb) free, with 100% matte-tin leadframe plating.


  • Mobile phone flash
  • Digital and film camera flash

Top Features

  • Low quiescent current draw (0.5 µA max in shutdown mode)
  • Primary-side output voltage sensing; no resistive divider required
  • User-adjustable current limit from 0.4 to 0.9 A
  • 1.1 V logic (VIH(min)) compatibility
  • Integrated constant voltage IGBT driver with separate sink and source
  • Optimized for mobile phone, 1-cell Li+ battery applications
  • Zero-voltage switching for lower loss
  • >75% efficiency
  • Charge Complete indication
  • Independent charge/trigger control
  • Integrated 40 V DMOS switch

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
A8737EEJTR-T 10-lead DFN -40°C to 85°C Yes View Data Discontinued Contact your
local sales rep
Distributor Stock
A8738EEJTR-T 10-lead DFN -40°C to 85°C Yes View Data Discontinued Contact your
local sales rep
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.