A8500中文资料灵活WLED / RGB背光驱动器，用于中型LCD数据手册Allegro规格书

描述 Description

This device is in production, however, it has been deemed Pre-End of Life. The product is approaching end of life. Within a minimum of 6 months, the device will enter its final, Last Time Buy, order phase. Date of status change: December 5, 2018

Recommended Substitutions: Contact Allegro Sales.

The A8500 is a multi-output WLED driver for medium display backlighting. The A8500 integrates a boost converter and eight current-sinks to provide a flexible WLED/RGB backlight driver. The boost converter can provide output voltage up to 47 V. The flexible channel selection control and high voltage capability allow a wide range of LED backlight applications. The A8500 can support any application requiring 4 to 96 WLEDs. The boost converter is a constant frequency current-mode converter.

Each LED channel can sink 25 mA, and channels can be paralleled for higher currents. Flexible dimming allows output channels to either run at an adjustable DC value or with externally controlled PWM duty cycles.

The A8500 is available in a 26 pin, 4 mm × 4 mm QFN/MLP package that is only 0.75 mm nominal in height.

Applications include:

Thin notebook displaysLCD TVRGB backlightGPS systemsPortable DVD players

特性 Features

• Active current sharing between LED strings for ±1.5% typical current matching and ±1.2% typical accuracy
• Drive up to 12 series × 8 parallel = 96 LEDs (Vf = 3.2 V, If = 20 mA)
• Flexible dimming, using alternative methods:

• LED duty cycle control (PWM pin)
• DC current using serial programming (EN pin)
• DC current using external PWM signal (APWM pin)
• An external resistor
• Boost converter with integrated 50 V, 2 A DMOS
• LED sinks rated for 25 mA
• 200 kHz to 2 MHz switching frequency
• Open LED disconnect
• Boost current limit, thermal shutdown, and soft start
• No audible ceramic capacitor noise during PWM dimming
• Adjustable overvoltage protection (OVP)
• No pull-up resistors required for LED modules that use ESD capacitors

简介

A8500属于集成电路（IC）的LED驱动器。由制造生产的A8500LED 驱动器器件属于 LED 驱动器电源管理集成电路 (PMIC) 系列，可通过标称固定电压的电源为负载（通常为发光二极管）提供电流，并且电流可控。它与用于电压调节的类似产品的主要区别在于，这类器件提供较低的反馈电压（以提高系统能效），而且通常可对器件工作点进行外部控制，可在照明应用中用于实现调光功能。