A3979中文资料微DMOS驱动器与翻译数据手册Allegro规格书

描述 Description

The A3979 is a complete microstepping motor driver with built-in translator, designed as a pin-compatible replacement for the successful A3977, with enhanced microstepping (1/16 step) precision. It is designed to operate bipolar stepper motors in full-, half-, quarter-, and sixteenth-step modes, with an output drive capacity of up to 35 V and ±2.5 A. The A3979 includes a fixed off-time current regulator that has the ability to operate in Slow, Fast, or Mixed decay modes. This current-decay control scheme results in reduced audible motor noise, increased step accuracy, and reduced power dissipation.

The translator is the key to the easy implementation of the A3979. It allows the simple input of one pulse on the STEP pin to drive the motor one microstep, which can be either a full step, half, quarter, or sixteenth, depending on the setting of the MS1 and MS2 logic inputs. There are no phase-sequence tables, high-frequency control lines, or complex interfaces to program. The A3979 interface is an ideal fit for applications where a complex microprocessor is unavailable or is overburdened.

Internal synchronous-rectification control circuitry is provided to improve power dissipation during PWM operation. Internal circuit protection includes: thermal shutdown with hysteresis, UVLO (undervoltage lockout), and crossover-current protection. Special power-on sequencing is not required.

The A3979 is supplied in a low-profile (maximum height ≤1.20 mm), 28-pin TSSOP with exposed thermal pad. The package is available in a lead (Pb) free version, with 100% matte tin leadframe plating.

特性 Features

• ±2.5 A, 35 V output rating
• Low RDS(On) outputs: 0.28 Ω source, 0.22 Ω sink, typical
• Automatic current decay mode detection/selection
• 3.0 to 5.5 V logic supply voltage range
• Slow, Fast or Mixed current decay modes
• Home output
• Synchronous rectification for low power dissipation
• Internal UVLO and thermal shutdown circuitry
• Crossover-current protection

简介

A3979属于集成电路（IC）的电机驱动器控制器。由Allegro制造生产的A3979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。