This page contains information on a product that is not recommended for new designs.
Suggested Replacement(s): MC33198
The MC33091A is a High–Side TMOS Driver designed for use in harsh automotive switching applications requiring the capability of handling high voltages attributed to load and field dump transients, as well as reverse and double battery conditions. Few external components are required to drive a wide variety of N–Channel TMOS devices. The MC33091A, driving an appropriate TMOS device, offers economical system solutions for high–side switching large currents. The MC33091A has CMOS compatible input control, charge pump to drive the TMOS power transistor, basic fault detection circuit, V DS monitoring circuit used to detect a shorted TMOS load, and overcurrent protection timer with associated current squaring circuitry. Short circuit protection is made possible by having a unique V DS voltage to current converter drive an externally programmable integrator circuit. This circuit affords fast detection of a shorted load while allowing difficult loads, such as lamps having high in–rush currents, additional time to turn on.
The Fault output is comprised of an open collector NPN transistor requiring a single pull–up resistor for operation. A fault is reported whenever the MOSFET on–current exceeds an externally programmed set level. The MC33091A is available in the plastic 8–Pin DIP package as well as the plastic 8–Pin surface mount package.