LOW CURRENT REGULATOR WITH NO QUIESCENT CURRENT
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2001-Oct-19
Battery-powered microprocessor electronics often requires a regulated voltage (e.g., 5 vdc) under operating conditions, while only using a lower standby voltage (e.g., 3.5 vdc) to retain RAM data when not operating. If the microprocessor system is comprised of CMOS devices, the standby current drain need only be on the order of microamps or less for small systems. However, most commercial regulators require some quiescent current to perform the regulation, which creates an additional battery drain under standby conditions, The circuit shown below solves this problem by supplying regulated voltage to the system in the "ON" mode, while drawing no supply current to provide unregulated RAM voltage in the "STANDBY" mode.