Description

The A8501 is a multioutput WLED/RGB driver for backlighting medium-size displays. The A8501 integrates a boost converter and four 100 mA current sinks. LED channels can be tied together for up to 400 mA sink capability. It can work from a single power supply of 8 to 21 V and withstand up to 40 V. The boost converter is a constant frequency, current-mode converter

Features and Benefits

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

? Internal bias supply for single-supply operation (VIN = 8 to 21 V)

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

? 3.5 μA shutdown current—limits battery drain

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

? Drive up to 9 series LEDs in 4 parallel strings, 36 LEDs maximum (Vf = 3.5 V, If = 100 mA)

? LED sinks rated for 100 mA each (400 mA total)

? 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

A8501屬于集成電路（IC） > LED 驅動器。Allegro MicroSystems制造生產(chǎn)的A8501LED 驅動器器件屬于 LED 驅動器電源管理集成電路 (PMIC) 系列，可通過標稱固定電壓的電源為負載（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），而且通常可對器件工作點進行外部控制，可在照明應用中用于實現(xiàn)調光功能。