A fully-protected DMOS/bipolar quad 1 A high-side switch

A quad high-side switch that, using a combined CMOS, DMOS, and bipolar isolated process, incorporates independent output-power-limiting cells for each output, a voltage tripler, and a status/error information port is described. The circuit is protected from overvoltage, overcurrent (including short circuits), and overtemperature. It operates on a 6-to-32-V supply range, requires zero standby current, and is protected to a maximum supply of 60 V. Applications include automotive and industrial resistive and reactive switching. The circuit is designed to be operated from a permanently connected 12-V battery, necessitating very low supply current when in the standby mode. The enabling circuit prebiases the internal voltage reference supply when the enable pin voltage exceeds a 0.8-V n-channel threshold. When the enable pin voltage rises above a 1.6-V critical threshold level, a reference provides a constant output voltage and a turn-on signal to the circuit. The gates of the output DMOS devices are held down when the enable pin is below the n-channel threshold, using a zero-standby-current CMOS clamp to prevent false turn-on during power supply cycling or high dV/dt.<>