A8507: LED Backlight Driver for LCD Monitors and Televisions

These parts are discontinued.  Samples are no longer available. For new customers or new applications, please contact Allegro. Date of status change: December 2, 2013.

The A8507 is a multi-output WLED/RGB driver for backlighting LCD monitors and televisions. The A8507 integrates a boost controller to drive external MOSFET and six internal current-sinks. The boost converter is constant frequency current mode converter.

PWM dimming allows LED currents to be controlled in 500:1 ratio. The LED sinks are capable of sinking up to 80 mA each, and can be paralleled together to achieve even higher currents.

The A8507 provides protection against overvoltage, open or shorted LED string, and overtemperature. A dual level cycleby- cycle current limit function provides soft start and protects against overloads.

The device is provided in a 24-pin SOICW package (LB), with internally fused pins for enhanced thermal dissipation, and a 24-pin TSSOP package (LP), with an exposed thermal pad for enhanced thermal dissipation. Both packages are lead (Pb) free, with 100% matte tin leadframe plating.

• Fixed frequency current mode control with integrated gate driver
• Each individual current sink is capable of 80 mA
• Adjustable overvoltage protection (OVP)
• Active current sharing between LED strings for ±0.6% accuracy and matching
• 250 kHz to 1 MHz adjustable switching frequency
• Open or shorted LED string protection
• Overtemperature, cycle-by-cycle current limit, and undervoltage protection
• No audible MLCC noise during PWM dimming
• No pull-up resistors required for LED modules that use ESD capacitors
• SOIC 24-pin package for easy single-side PCB manufacturing or TSSOP 24-pin package with exposed thermal pad for better thermal performance