Patent ID: 7129773
Filing Date: 2006-10-31
Classification: G05F

Abstract:
1. A band-gap type constant voltage generating circuit produced in a semiconductor chip and having a first potential terminal and a second potential terminal, which circuit comprises: a band-gap circuit including first and second transistors having respective bases connected to each other, a first resistor connected between emitters of said first and second transistors, and a second resistor connected between the emitter of said second transistor and said first potential terminal; a constant voltage production circuit provided between said first and second potential terminals to produce and output a constant voltage based on a base-emitter voltage of the second transistor of said band-gap circuit, with the constant voltage being fed as a feedback signal to the base of the second transistor of said band-gap circuit; and a driver circuit provided between said first and second potential terminals and connected to collectors of the first and second transistors to drive said band-gap circuit, wherein said driver circuit is constituted such that an influence of absolute process fluctuation, to which said semiconductor chip is subjected during a production process thereof, is eliminated from said constant voltage.