A band gap reference circuit includes an error-amplifier-based current mirror coupled between a first supply node and a pair of intermediate voltage nodes, and a matched diode pair for providing a proportional-to-absolute temperature (PTAT) current. The matched diode pair includes a first diode connected between a first intermediate voltage node from the pair of intermediate voltage nodes and a second supply node, and a second diode connected in series with a resistor between a second intermediate voltage node from the pair of intermediate voltage nodes and the second supply node. Each diode has a P-N diode junction that is a homojunction.