BJT-Boosted Zener Reference Volt. Regulator With Digital ON/OFF Control

The circuit is a BJT-boosted Zener voltage regulator which can be turned ON or OFF by a digital signal. Two interfaces are utilized in the circuit. The first simply uses a diode to interface to a signal with logic high state voltage greater than the Zener diode voltage. The second interface uses a BJT inverter. This is useful when the driving circuit is powered from a lower voltage and can be damaged by the Zener voltage. The switches and the associated voltage sources represents a digital signal.