A3938中文资料三相功率MOSFET控制器数据手册Allegro规格书

描述 Description

The A3938 is a three-phase, brushless DC motor controller. It has a high-current gate drive capability that allows driving of a wide range of power MOSFETs and can support motor supply voltages to 50 V. The A3938 integrates a bootstrapped high-side driver to minimize the external component count required to drive N-channel MOSFET drivers.

Internal fixed off-time, PWM current-control circuitry can be used to regulate the maximum load current to a desired value. The peak load current limit is set by the user’s selection of an input reference voltage and external sensing resistor. A userselected external RC timing network sets the fixed off-time pulse duration. For added flexibility, the PWM input can provide speed/torque control where the internal current control circuit sets a limit on the maximum current.

The A3938 includes a synchronous rectification feature. This shorts out the current path through the power MOSFET reverse body diodes during PWM off-cycle current decay. This can minimize power dissipation in the MOSFETs, eliminate the need for external power clamp diodes, and potentially allow a more economical choice for the MOSFET drivers.

The A3938 provides commutation logic for Hall sensor ICs configured for 120-degree spacing. The Hall input pins are pulled up to an internally-generated 5 V reference. Power MOSFET protection features include: bootstrap capacitor charging current monitor, regulator undervoltage monitor, motor lead short-to-ground, and thermal shutdown. Allegro recommended hall latches: APS13290-1.

特性 Features

• Drives a wide range of N-channel MOSFETs
• Low-side synchronous rectification
• Power MOSFET protection
• Adjustable dead time for cross-conduction protection
• Selectable coast or dynamic brake on power-down or RESET input
• Fast/slow current decay modes
• Internal PWM current control
• Motor lead short-to-ground protection
• Internal 5 V regulator
• Fault diagnostic output
• Thermal shutdown
• Undervoltage protection

简介

A3938属于集成电路（IC）的电机驱动器控制器。由制造生产的A3938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。