The LMD18400 is a fully protected quad high side driver It contains four common-drain DMOS N-channel power switches each capable of switching a continuous 1 Amp load (l3 Amps transient) to a common positive power supply The switches are fully protected from excessive voltage current and temperature An instantaneous power sensing circuit calculates the product of the voltage across and the current through each DMOS switch and limits the power to a safe level The device can be disabled to produce a ``sleep'' condition reducing the supply current to less than 10 mA Separate ON OFF control of each switch is provided through standard LSTLL CMOS logic compatible inputs A MICROWIRETM compatible serial data interface is built in to provide extensive diagnostic information This information includes switch status readback output load fault conditions and thermal and overvoltage shutdown status There are also two direct-output error flags to provide an immediate indication of a general system fault and an indication of excessive operating temperature The LMD18400 is packaged in a special power dissipating leadframe that reduces the junction to case thermal resistance to approximately 20 C W