A DC to DC converter is disclosed wherein the output voltage is regulated by the control of current pulses in an inverter stage. The converter output voltage and a defined reference voltage are compared to generate error signals and current flow in the inverter stage is monitored to generate proportional current signals. The error signals are directly compared to the current signals by a comparing circuit which comprises a voltage ampliflier and a current source. The error signals are coupled to the voltage amplifier which maintains a corresponding voltage on one side of a resistor. The current signals are coupled to the current source which is connected to the other side of the resistor and maintains the current flow through the resistor at a level equal to the current signals. Current pulses in the inverter stage are initiated by pulses from a pulse generator circuit and terminated when the current signals exceed a current threshold level which is defined as the voltage maintained on the resistor divided by the resistance value of the resistor.