
Allegro MicroSystems
Description
The A8516 is a multi-output WLED/RGB driver for backlighting LCD monitors and televisions. It integrates a boost controller to drive external MOSFET, and six internal currentsinks. The boost converter operates in constant frequency (programmable) current mode control.
The LED sink current is set by an external R_ISET resistor (see chart below). More than one LED sinks can be combined together to achieve even higher current per LED string.
The A8516 operates from a single supply of 8 to24 V. It provides protection against overvoltage, open or shorted LED string, and overtemperature. A dual level cycle-by-cycle current limit function provides soft start and protects against overloads.
FEATUREs and Benefits
▪ Six integrated high current sinks
▪ Fixed frequency current mode control with integrated gate driver
▪ 300 kHz to 1 MHz adjustable Boost switching frequency
▪ Controlled startup using options of Enable, PWM signal, or battery voltage ramp
▪ Active current sharing between LED strings for ±0.6% accuracy and matching
▪ No audible MLCC noise during PWM dimming
▪ Adjustable overvoltage protection (OVP)
▪ Open or shorted LED string protection
▪ Overtemperature, cycle-by-cycle current limit, and undervoltage protection
▪ SOIC 24-pin package for easy single-side PCB manufacturing, or TSSOP 24-pin package with exposed thermal pad for better thermal performance