A8502中文资料宽输入电压范围，高效率数据手册Allegro规格书

描述 Description

The A8502 is a multi-output white LED driver for small-size LCD backlighting. It integrates a current-mode boost converter with internal power switch and two current sinks. The boost converter can drive up to 24 LEDs, 12 LEDs per string, at 120 mA. The LED sinks can be paralleled together to achieve even higher LED currents, up to 240 mA. The A8502 can operate with a single power supply, from 5 to 40 V, which allows the part to withstand load dump conditions encountered in automotive systems.

If required, the A8502 can drive an external P-FET to disconnect the input supply from the system in the event of a fault. The A8502 provides protection against output short and overvoltage, open or shorted diode, open or shorted LED pin, shorted boost switch or inductor, shorted FSET or ISET resistor, and IC overtemperature. A dual level cycle-by-cycle current limit function provides soft start and protects the internal current switch against high current overloads.

The A8502 has a synchronization pin that allows PWM switching frequencies to be synchronized in the range of 580 kHz to 2.3 MHz. The high switching frequency allows the A8502 to operate above the AM radio band.

The A8502 is provided in a 16-pin TSSOP package (suffix LP) with an exposed pad for enhanced thermal dissipation. It is lead (Pb) free, with 100% matte tin lead frame plating.

特性 Features

• Wide input voltage range of 5 to 40 V for start/stop, cold crank and load dump requirements
• Sync function to synchronize boost converter switching frequency up to 2.3 MHz, allowing operation above the AM band
• Single resistor primary OVP minimizes VOUT leakage
• LED current of 120 mA per channel
• 0.7% to 0.8% LED to LED matching accuracy
• 5000:1 PWM dimming at 200 Hz
• Extensive protection against:
• Shorted boost switch or inductor
• Shorted output
• Open boost Schottky
• Overtemperature (OTP)

简介

A8502属于集成电路（IC）的LED驱动器。由制造生产的A8502LED 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。