The A8512 is a multi-output WLED/RGB for midsize display backlightingdrive。 The A8512 combines a boost controller to drive external MOSFETs and six internal current sinks. The boost converter operates in constant frequency (programmable) current mode.
PWM dimming ensures that LED current is controlled at a 500:1 ratio. Each LED sinks 80 mA and can be paralleled to provide higher current. In addition, multiple A8512s can be connected in parallel, using a master controller to control the boost stage, and up to five slave controllers can be connected that act as LED sinks. In this way, only one is neededBoost converterPower up to 36 LED strings.
The A8512 operates from a single supply and has a voltage range of 8 to 24V. It provides protection against overvoltage, open LED string, short circuit, and overtemperature. Two-stage wave-by-wave current limit provides soft-start and overload protection.
The device is available in a 24-pin SOICW package (LB) with built-in stub pins for enhanced heat dissipation and a 28-contact 5 mm × 5 mm QFN package (ET) with external thermal pads for enhanced thermal dissipation. Both packages are lead (Pb) free and feature 100% matte tin coated leadframes.
- Six independent current sinks, each capable of delivering 80 mA
- Constant frequency current mode control with integrated gate driver
- 300 kHz to 1 MHz adjustable switching frequency
- Use options such as enable, PWM signal, or battery voltage ramp to control startup
- It can work in parallel with a boost controller (master controller) and up to five slave controllers
- Autonomous current sharing between LED strings achieves ±0.6% accuracy and matching
- There is no audible ceramic capacitor noise during PWM dimming control
- Adjustable Overvoltage Protection (OVP)
- Open or shorted LED string protection
- Over-temperature, wave-by-wave current limit, and under-voltage protection
- The SOIC 24-pin package facilitates single-sided PCB production, while the QFN 28-contact package with external thermal pad improves thermal performance