The 3955 is designed for driving one winding of a bipolar stepper motor in a microstepping mode. The outputs are rated for continuous output currents to ±1.5 A and operating voltages to 50 V. Internal pulse-width modulated (PWM) current control combined with an internal three-bit non-linear digital-to-analog converter allows the motor current to be controlled in full-, half-, quarter-, or eighth-step (microstepping) modes. Nonlinear increments minimize the number of control lines necessary for microstepping. Microstepping provides for increased step resolution, and reduces torque variations and resonance problems at low speed.
Internal circuitry determines whether the PWM current-control circuitry operates in a slow (recirculating) current-decay mode, fast (regenerative) current-decay mode, or in a mixed current decay with the remainder of the fixed off time spent in slow current decay. The combination of user-selectable current-sensing resistor and reference voltage, digitally selected output current ratio; and slow, fast, or mixed current-delay modes provides users with a broad, variable range of motor control.
Internal circuit protection includes thermal shutdown with hysteresis, transient-suppression diodes, and crossover current protection. Special power-up sequencing is not required.
The A3955S— is supplied in a choice of two power packages; a 16-pin dual-in-line plastic package with copper heat-sink tabs (suffix 'B'), and a 16-lead plastic SOIC with copper heat-sink tabs (suffix 'LB'). For both package styles, the power tab is at ground potential and needs no electrical isolation. Both packages are available in a lead-free version (leadframe plating 100% matte tin), indicated by suffix -T.
声明:本文内容及配图由入驻作者撰写或者入驻合作网站授权转载。文章观点仅代表作者本人,不代表电子发烧友网立场。文章及其配图仅供工程师学习之用,如有内容侵权或者其他违规问题,请联系本站处理。 举报投诉
全部0条评论
快来发表一下你的评论吧 !