The design of an automotive low drop out regulator IC utilizing a depletion mode high voltage DMOS pass element

In this paper the design of a new low dropout voltage regulator utilizing a high voltage depletion mode NMOS device as a pass element is described. A novel method of compensation is utilized which allows the circuit to be stable over a wide range of output capacitance and ESR. A watchdog timer is included with this circuit. The regulator is capable of sourcing 500 ma in regulation but is limited by forward drop and power dissipation.