Band gap reference circuit

摘要

A band gap reference includes circuitry providing a reference voltage (VDIODE) at 1.0 volt or below to provide a stable reference for 1.3 volt or lower circuits, which would otherwise not function accurately with a typical band gap reference of 1.2 volts. The band gap reference includes an op-amp equally driving the gate of various current source transistors. A first current source drives a BJT transistor connected in a diode fashion, while a second current source drives a further diode connected BJT transistor through a resistor. An output VDIODE is provided from a further resistor connected to two additional current sources. The first of these current sources is driven by the op-amp output to increase output with temperature, while the second of these current sources is driven by a replicating op-amp connected to a resistor providing current decreasing with temperature, both current sources functioning to provide a stable low voltage VDIODE on the resistor with variations in temperature and supply voltage.