A8511屬于集成電路（IC）的LED驅(qū)動(dòng)器。由Allegro MicroSystems制造生產(chǎn)的A8511LED 驅(qū)動(dòng)器器件屬于 LED 驅(qū)動(dòng)器電源管理集成電路 (PMIC) 系列，可通過(guò)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?duì)器件工作點(diǎn)進(jìn)行外部控制，可在照明應(yīng)用中用于實(shí)現(xiàn)調(diào)光功能。

描述 Description

The A8511 is a multioutput WLED/RGB driver for backlighting medium-size displays. It is a fully integrated high-brightness (HB) LED driver solution that does not require external power devices to complete the backlighting design criteria. The A8511 integrates FETs for a boost converter as well as four 150 mA current sinks, offering a complete integrated solution at HB LED current levels. LED channels can be tied together for up to 600 mA sink capability. It can work from a single power supply of 6.8 to 21 V and withstand up to 40 V. The boost converter is a constant frequency, current-mode converter.

Features and Benefits

? Four LED sinks rated for 150 mA each (600 mA total)

? Boost converter with integrated 40 V DMOS switch and OVP–load-dump protection

? 600 kHz to 2.2 MHz switching frequency—ability to operate above the AM band

? Internal bias supply for single-supply operation (VIN= 6.8 to 21 V)

? 3.5 μA shutdown current—limits battery drain

? Active current sharing between LED strings for 0.8 current matching and 0.7 accuracy

? PWM dimming with LED PWM duty cycle control

? 4000:1 dimming range

? Extensive fault mode protection schemes:

? Shorted LED protection against misconnected loads—with true output disconnect

? Open LED disconnect protects against LED failures

? External thermistor sensing to limit LED temperature

? Output overvoltage protection (OVP): 19.5 V default can be adjusted as high as 38 V

? Open Schottky and open OVP resistor protection against external component failure

? Input under- and overvoltage protection (UVLO and OVLO) against VIN variation

? Boost current limit, output short circuit limit, overtemperature protection (OTP), and soft start

Applications include:

? GPS navigation systems

? Automotive infotainment

? Back-up camera displays

? Cluster backlighting

? Portable DVD players

? Industrial LCD displays