The TL496C power-supply control circuit is designed to provide a 9-V regulated supply from a variety of input sources. Operable from a 1- or 2-cell battery input, the TL496C performs as a switching regulator with the addition of a single inductor and filter capacitor. When ac coupled with a step-down transformer, the TL496C operates as a series regulator to maintain the regulated output voltage and, with the addition of a single catch diode, time shares to recharge the input batteries.
The design of the TL496C allows minimal supply current drain during standby operation (125 µA typical). With most battery sources, this allows a constant bias to be maintained on the power supply. This makes power instantly available to the system, thus eliminating power-up sequencing problems.