A multi-stage laser drive circuit configured to draw current from a variable common potential source, comprising: a current node; a first power amplifier 'PA' light-emitting array in electrical communication between a storage capacitor and the current node through a digitally controllable ON/OFF switch, the storage capacitor being charged by the variable common potential source through a charge control circuit; a first low side linear current sink in electrical communication with the current node, the first low side linear current sink being configured to draw a first current from the storage capacitor through the ON/OFF switch, through the current node; a second low side linear current sink in electrical communication with the current node and in a parallel arrangement with respect to the first low side linear current sink, the second low side linear current sink being configured to draw a second current from the storage capacitor through the ON/OFF switch, through the current node; a second master oscillator 'MO' light-emitting array in electrical communication between the current node and the first low side linear current sink, wherein current through the first light-emitting array is the sum of the first and second currents in parallel, wherein output light from the first PA light-emitting array is used to pump a first PA laser gain medium; wherein output light from the second MO light-emitting array is used to pump a second MO laser gain medium; a trickle current circuit located between the common potential source and an anode of a laser diode at a top of the first PA light-emitting array for driving a low-value trickle current through the first and second light emitting arrays and through a large fixed shunt resistor in parallel with the first low side linear current sink; a sense circuit for sensing a voltage indicative of a magnitude of the trickle current at an input of the first low side linear current sink and generating a signal indicative of the voltage; and a digital controller for generating a switch control signal to control the ON/OFF switch such that the first and second currents are prevented from flowing if the signal indicative of the trickle voltage indicates that the trickle voltage is outside a voltage range to indicate a malfunction, the malfunction being one of an open circuit and a short circuit, indicated by the trickle voltage. a current node; a first power amplifier 'PA' light-emitting array in electrical communication between a storage capacitor and the current node through a digitally controllable ON/OFF switch, the storage capacitor being charged by the variable common potential source through a charge control circuit; a first low side linear current sink in electrical communication with the current node, the first low side linear current sink being configured to draw a first current from the storage capacitor through the ON/OFF switch, through the current node; a second low side linear current sink in electrical communication with the current node and in a parallel arrangement with respect to the first low side linear current sink, the second low side linear current sink being configured to draw a second current from the storage capacitor through the ON/OFF switch, through the current node; a second master oscillator 'MO' light-emitting array in electrical communication between the current node and the first low side linear current sink, wherein current through the first light-emitting array is the sum of the first and second currents in parallel, wherein output light from the first PA light-emitting array is used to pump a first PA laser gain medium; wherein output light from the second MO light-emitting array is used to pump a second MO laser gain medium; a trickle current circuit located between the common potential source and an anode of a laser diode at a top of the first PA light-emitting array for driving a low-value trickle current through the first and second light emitting arrays and through a large fixed shunt resistor in parallel with the first low side linear current sink; a sense circuit for sensing a voltage indicative of a magnitude of the trickle current at an input of the first low side linear current sink and generating a signal indicative of the voltage; and a digital controller for generating a switch control signal to control the ON/OFF switch such that the first and second currents are prevented from flowing if the signal indicative of the trickle voltage indicates that the trickle voltage is outside a voltage range to indicate a malfunction, the malfunction being one of an open circuit and a short circuit, indicated by the trickle voltage.