Patent ID: 6100754
Filing Date: 2000-08-08
Classification: G05F

Abstract:
A reference voltage generator circuit for use with an extremely low first power supply potential for producing a lower reference output voltage which is compensated for variations in temperature and the power supply potential, said reference voltage generator circuit comprising:first and second parallel current branches connected between the extremely low first power supply potential and a second power supply potential, said first branch including a first P-channel MOSFET transistor, a second P-channel MOSFET transistor, a first N-channel MOSFET transistor and a first resistor connected in series, said second branch including a third P-channel MOSFET transistor, a fourth P-channel MOSFET transistor, and a second N-channel MOSFET transistor connected in series, said first resistor having a first voltage developed thereacross with a positive temperature coefficient;a third parallel current branch connected also between the first extremely low power supply potential and the second power supply potential, said third branch including a fifth P-channel MOSFET transistor, a sixth P-channel MOSFET transistor, a second resistor and a third N-channel MOSFET transistor connected in series, said third N-channel MOSFET transistor having a second voltage with a negative temperature coefficient;a fourth branch formed of a seventh P-channel MOSFET transistor and an eighth P-channel MOSFET transistor being connected in series, said fourth branch being connected in parallel across the conduction path of said fifth and sixth P-channel MOSFET transistors;gate-bias circuit means for generating a first gate-bias voltage connected to the gates of said first, third, fifth and seventh P-channel transistors and a second gate-bias voltage connected to the gates of said second, fourth, sixth and eighth P-channel transistors so as to maintain constant the current flowing through said first and second P-channel transistors as variations in the power supply potential occurs; andsaid second resistor and said third N-channel transistor establishing the lower reference output voltage which is temperature and power supply compensated.