PWM MOTOR DRIVING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To realize a PWM motor driving circuit which is driven at a high speed, small, low loss and highly reliable.

SOLUTION: The drain of a p channel MOSFET transistor Tru+whose source is connected to a power supply +VDDis connected to the drain of an n channel MOSFET transistor Tru-whose source is connected to a GND, thereby forming an output of a motor coil. Also, a bias resistor R4 is connected between the source of the p channel MOS transistor Tru+and the gate thereof, a transistor Q2 for short-circuiting the source and the gate when the p channel MOS transistor Tru+is turned off is provided in parallel to the resistor R4. The gate is connected to a collector, and the emitter of an input npn transistor Q1 whose base is connected to the power supply +VDDis connected to a port P1 of a microcomputer 2. In contrast, the gate of the n channel MOS transistor Tru-is connected to a port P2 of the microcomputer 2, and driving signals are inputted to both the ports P1, P2. Using this circuit realizes the simple PWM motor driving circuit which can performs high-speed operation, be miniaturized, is low loss and highly reliable.

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