A8508屬于集成電路（IC）的LED驅(qū)動器。由Allegro MicroSystems制造生產(chǎn)的A8508LED 驅(qū)動器器件屬于 LED 驅(qū)動器電源管理集成電路 (PMIC) 系列，可通過標(biāo)稱固定電壓的電源為負(fù)載（通常為發(fā)光二極管）提供電流，并且電流可控。它與用于電壓調(diào)節(jié)的類似產(chǎn)品的主要區(qū)別在于，這類器件提供較低的反饋電壓（以提高系統(tǒng)能效），而且通?？蓪ζ骷ぷ鼽c進(jìn)行外部控制，可在照明應(yīng)用中用于實現(xiàn)調(diào)光功能。

描述 Description

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.

Features and Benefits

? 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)