Abstract: A trimmable bandgap voltage reference circuit includes variable current sources to drive variable currents through parallel combination circuits. The parallel combination circuits include variable resistors and diodes of differing sizes. Voltages developed across the parallel combination circuits are input to a differential amplifier that is used as a feedback amplifier to bias the variable current sources. The variable current sources and variable resistors can all be digitally controlled. A processor can query the operating point of the bandgap voltage reference circuit, and can also set the current and resistance values through a control circuit.