A Thermal Shutdown Circuit for Motor Driver IC

A thermal shutdown protection circuit for motor driver IC was designed,which consisted of setup circuit,bandgap voltage reference,temperature detection and comparator output circuits.The temperature detection circuit took advantage of the negative temperature coefficient characteristics of PNP transistor's emitter-base voltage.Temperature hysteresis comparator was used to prevent thermal oscillation.HSPICE simulation showed that the thermal shutdown circuit had high sensitivity to temperature and the temperature threshold was stable under different supply voltages.