AN INTELLIGENT BICMOS DMOS QUAD-1-A HIGH-SIDE SWITCH

A fully protected quad high-side DMOS switch has been realized using a jointly developed BiCMOS/DMOS process [1]. A bipolar multiplier cell calculates and limits instantaneous power dissipated by each 0.8-Ω DMOS power switch to 13 W. The integrated circuit shuts down to protect itself if a safe temperature or operating voltage is exceeded. A thermal warning is provided when the junction temperature rises to within 20°C of the shutdown temperature such that an orderly system shutdown sequence can be executed before unilateral switch turn-off occurs. A serial-output data pin reports status information including channel on/off, open and shorted load faults, warning and shutdown temperatures, and an overvoltage condition. The circuit withstands a supply voltage of 60 V and operates from 6 to 32 V. The IC can be permanently connected to the power source while drawing no dc current in the standby mode. The device fits into a 20-pin dual-in-line package having the die-attach paddle and the center four pins of the lead frame being a continuous strip of metal providing a low thermal resistance path from which to extract heat from the output switches. © 1990 IEEE