This regulator can be controlled by a logic signal. The circuit is from an Electronics Now from the 90s. Note that the switching transistor is before the integrated circuit.
Found in a 1967 US magazine this circuit generates positive and negative voltage pulses from a...
With this circuit we can control a load from 500 mA to 1 A, depending on the transistor, using a low...
The circuit shown in the figure is suggested by Texas Instruments in its Linear Circuits...