cortex-m3,当前控制领域最有名气的微控制器，相当于arm7的升级版-cortex-m3, the current control of the most famous micro-controller, the equivalent of an upgraded version of arm7

A3977 带转换器的微步 DMOS 驱动器 特点 ±2.5 A、35 V 输出额定值 低 rDS(开)输出（一般为 0.45 Ω源极，0.36Ω灌电流） 自动检测/选择电流-A3977 DMOS drive characteristics with micro-step converter ± 2.5 A, 35 V output rating of low, rDS (open) output (typically 0.45 Ω source very, 0.36Ω current sink