Bandgap voltage reference employing sub - surface current using a standard cmos process

摘要

A bandgap voltage reference employing only subsurface currents wich may be fabricated using a standard CMOS process. The reference includes first and second vertical bipolar transistors having common collectors formed in an integrated circuit substrate. A first resistor connects the emitter of the first transistor to ground potential. A second resistor connects the emitter of the second transistor to a reference node while a third resistor connects the reference node to ground. A differential amplifier has a positive input connected to the reference node, a negative input connected to the first transistor emitter and an output connected to the bases of the first and second transistors and also providing the reference voltage output. In a preferred form the output of the differential amplifier is buffered by a third transistor and coupled by a resistive divider to the first and second transistor bases so that the reference voltage may be selected at any scalar of the basic bandgap voltage.