A4957中文资料Full Bridge MOSFET Driver数据手册Allegro规格书

描述 Description

The A4957 is a full-bridge controller for use with external N-channel power MOSFETs and is specifically designed for applications with high-power inductive loads such as brush DC motors.

A unique charge pump regulator provides full ( >10 V ) gate drive for battery voltages down to 7 V and allows the A4957 to operate with a reduced gate drive, down to 4.5 V.

A bootstrap capacitor is used to provide the above battery supply voltage required for N-channel MOSFETs. A unique bootstrap charge management system ensures that the bootstrap capacitor is always sufficiently charged to supply the high-side gate drive circuit.

Each of the power MOSFETs is controlled independently but all are protected from shoot-through by dead time that is userconfigured by an external resistor.

Integrated diagnostics provide indication of undervoltage and overtemperature faults.

The A4957 is supplied in a 24-contact 4 mm × 4 mm × 0.75 mm QFN with an exposed pad for enhanced thermal dissipation. It is lead (Pb) free, with 100% matte tin leadframe plating (suffix –T).

特性 Features

• High current gate drive for N-channel MOSFET full bridge
• Independent control of each MOSFET
• Charge pump for low supply voltage operation
• Cross-conduction protection with adjustable dead time
• 4.5 to 50 V supply voltage range
• Diagnostics output
• Low current sleep mode

简介

A4957属于集成电路（IC）的电机驱动器控制器。由制造生产的A4957电机驱动器，控制器产品属于电机驱动器和控制器电源管理集成电路 (PMIC) 系列，可用于控制或操作从某电源施加到电机或相关机电执行器的电源。所实现的具体功能和特性集根据预期负载和预期应用的特性有很大差异，范围从用于有刷电机的简单开环速度控制到基于步进电机的高级闭环运动控制。