
Allegro MicroSystems
Description
The A8515 is a multi-output white LED (WLED) driver for LCD backlighting in consumer and industrial displays. It integrates a current-mode boost converter with an internal power DMOS switch and two current sinks. The boost converter can drive up to 24 LEDs: 12 LEDs per string at 120 mA. The LED sinks can be paralleled together to achieve higher LED currents, up to 240 mA. The A8515 can operate from a single power supply, from 5 to 40 V.
FEATUREs and Benefits
• Wide input voltage range: 5 to 40 V
• Maximum LED current of 120 mA
• TSSOP-16 (LP) package; exposed pad offers best-in-class thermal performance
• Typical LED accuracy of 0.5%, and 0.5% for LED-to-LED matching
• Internal bias supply for single-supply operation (typically between VIN = 8 to 24 V)
• Integrated boost converter with 60 V DMOS switch with overvoltage protection (OVP)
• Drives up to 12 series LEDs in 2 parallel strings
• Single EN/PWM pin interface for both PWM dimming and enable function
• Sync function to synchronize boost converter switching frequencies up to 2.3 MHz, this gives the designer the ability minimize component size
• Provides driver for external PMOS input disconnect switch
• Protection features:
▫ Open or shorted VLED pin protection
▫ Open Schottky protection
▫ Cycle-by-cycle current limit
▫ Overtemperature protection (OTP)
▫ Output short circuit protection
APPLICATIONs
• Desktop LCD flat panel displays (FPD)
• Flat panel video displays
• LCD TVs and monitors