A8508: Wide Input Voltage Range, High Efficiency 8-Channel Fault Tolerant LED Driver

The A8508 is a multi-output white LED driver for backlighting LCD panels. It integrates a current-mode boost controller and eight individual current sinks.

The boost controller architecture allows for significant scaling of boost voltage to optimize the solution for the required number of LEDs per string. The FSET/SYNC pin either sets the required boost switching frequency or synchronizes the value in the range of 300 to 800 kHz.

The LED sink current value is set by an external ISET resistor (see figure 1). The eight LED sinks can also be combined to achieve even higher current per LED string.

The A8508 provides protection against output shorts and overvoltage, open or shorted LED pins, and overtemperature. A dual-level, pulse-by-pulse current limit function provides soft start and protects the external current switch against high current overloads. As an option, the A8508 can drive an external P-FET interfaced to the FAULT pin to disconnect the input supply from the system in the event of short-to-ground in the boost converter.

The A8508 is available in a 24-pin TSSOP package (suffix LP) with an exposed thermal pad for enhanced thermal dissipation. Contact factory for additional options, including: a 24-pin SOICW (LW) or a a 5 × 5 mm 28-contact QFN (ET) with exposed thermal pad. All packages are lead (Pb) free, with 100% matte tin leadframe plating.

DATASHEETS
SAMPLE & BUY

Astrorep Inc. (Allegro and Sanken Semiconductors, Sanken Power Supplies)
141 John Street, Suite 300
Babylon, NY 11702
Phone: (631)422-2500
Fax: (631)422-2504
Web: www.astrorepinc.com
Email: donna.tweedy@astrorepinc.com

If this is not your local representative, find your local sales rep here.

RECEIVE PRODUCT ALERTS
We'll notify you when there are updates to this product. Sign Up
  • Features and BenefitsFeatures and Benefits
  • PackagingPackaging
  • Technical DocsTechnical Docs
  • NewsNews
  • Eight integrated high current sinks for LED strings; can be tied together for even higher currents
  • Fixed frequency current mode control with integrated gate driver / boost controller; powerful gate driver to drive an external N-channel MOSFET allows significant scaling capability on the number of LEDs per string
  • Parallel operation capability with one boost controller master) and up to three additional slave controllers; can run up to 32 strings of LEDs while populating only a single master boost regulator
  • Active current sharing between LED strings for 0.7% accuracy and 0.8% matching
  • Wide input voltage range: 9 to 40 V
  • Internal bias supply for single-supply operation (typically VIN = 12 or 24 V)
  • Fset / Sync function to either set the boost converter switching frequency or synchronize at up to 800 kHz
  • Protection Features
    • Open or shorted LED pin protection
    • Open Schottky protection
    • Pulse-by-pulse current limit
    • Overtemperature protection (OTP)

The A8508 is available in a 24-pin TSSOP package (suffix LP) with an exposed thermal pad for enhanced thermal dissipation. Contact factory for additional options, including: a 24-pin SOICW (LW) or a a 5 × 5 mm 28-contact QFN (ET) with exposed thermal pad. All packages are lead (Pb) free, with 100% matte tin leadframe plating.

LP TSSOP 24 pin

There are no news items available for this product.

Click the image to view larger
Product Image Typical Application Functional Block Diagram

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Compliant
Part Composition /
RoHS Data
Comments Samples Check
Distributor Stock
A8508GETTR-T 28-lead QFN -40°C to 105°C Yes View Data Contact factory Contact your
local sales rep
Check Stock
A8508GLPTR-T 24-lead TSSOP -40°C to 105°C Yes View Data Contact your
local sales rep
Check Stock
A8508GLWTR-T 24-lead SOIC -40°C to 105°C Yes View Data Contact factory Contact your
local sales rep
Check Stock
APEK8508GLP-01-MH DEMO BOARD -40°C to 105°C No -- Contact your
local sales rep
Check 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.

Copyright © 2017 Allegro MicroSystems, LLC

Sitemap  |  Privacy Policy  |  Contact Webmaster

Follow us on: LinkedIn YouTube Google+ Follow Allegro on Twitter

Careers   |   Contact Sales   |   Home   |   Legal   |   Quality & Environment   |   Request Samples