Patent ID: 6489835
Filing Date: 2002-12-03
Classification: G05F

Abstract:
A system for providing a bandgap reference voltage, the system comprising:first and second PMOS transistors, connected at their gates to a drain of the second PMOS transistor and to a negative input terminal of an operational amplifier having a selected supply voltage, with a drain of the first PMOS transistor connected to a positive input terminal of the amplifier; first and second bipolar transistors, with bases and collectors connected to ground, with the first and second bipolar emitters connected to the first PMOS transistor drain and through a first resistor to the second PMOS transistor drain, respectively; a second resistor connected between the drain of the second PMOS transistor and ground; a third PMOS transistor having a drain connected through a third resistor to ground; and a fourth PMOS transistor, serving as a current source, having a gate connected to the gates of the first, second and third PMOS transistors, and having a source connected to sources of the first, second and third PMOS transistors and to an output terminal of the amplifier.