Allegromicro A4986全桥步进马达驱动方案
Allegromicro公司的A4986是双DMOS全桥步进马达驱动器,具有并行输入通信和过流保护,每个全桥输出额定电压高达35V,电流±2 A. A4986兼容3.3V和5V逻辑电平,睡眠电流小于10uA.本文介绍了A4986主要特性和优势, 功能方框图, 典型应用框图以及PCB应用布局图.
The A4986 is a dual DMOS full-bridge stepper motor driver with parallel input communication and overcurrent protection. Each full-bridge output is rated up to 35 V and ±2 A.
The A4986 includes fixed off-time pulse width modulation (PWM) current regulators, along with 2- bit nonlinear DACs (digital-to-analog converters) that allow stepper motors to be controlled in full, half, and quarter steps. The PWM current regulator uses the Allegro® patented mixed decay mode for reduced audible motor noise, increased step accuracy, and reduced power dissipation.
Internal synchronous rectification control circuitry is provided to improve power dissipation during PWM operation. The outputs are protected from shorted load and short-toground events, which protect the driver and associated circuitry from thermal damage or flare-ups. Other protection features include thermal shutdown with hysteresis, undervoltage lockout (UVLO) and crossover current protection. Special power-up sequencing is not required.
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