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US 4,396,883 AGranted
Bandgap reference voltage generator
AssigneeInternational Business Machines Corporation
InventorsJohn F. Holloway, Salvatore R. Riggio, Jr.
Life of this patent
Estimating the term…
Abstract
A bandgap reference voltage generator consists of a plurality of transistors with the same geometry. This circuit provides a stable temperature-compensated low reference voltage on the order of two volts.
Claims14
A temperature compensated reference voltage generator circuit comprising:
- a current supply circuit;
- a first transistor having its collector coupled to a first side of said current supply circuit;
- a first resistor coupled between the emitter of said first transistor and a second side of said current supply circuit;
- a plurality of transistors of the same geometry as said first transistor, each having its collector coupled to said first side of said current supply circuit;
- a plurality of resistors each of approximately the same resistance as said first resistor, individually coupled between the emitter of a respective one of said plurality of transistors and the emitter of said first transistor;
- a feedback circuit means coupled to a first side of said current supply circuit, the base of said first transistor and the bases of said plurality of transistors, a second side of said current supply circuit, and the collector of said first transistor;
- said feedback circuit responsive to the difference between the current flowing through said first transistor and the total current flowing through all of said plurality of transistors for supplying a voltage to the bases of said first transistor and said plurality of transistors to reduce this difference in current flow to substantially zero;
- and
- an output terminal means coupled to said feedback circuit means for providing a stable temperature-compensated reference voltage;
- whereby said reference voltage is not substantially effected by thermally induced resistance variations in said first resistor and said plurality of resistors.
7 more elements
A temperature compensated reference voltage generator circuit comprising:
- a current supply circuit;
- a start-up circuit coupled to a first side of said current supply circuit;
- a first transistor having its collector coupled to said first side of said current supply circuit and a second side of said current supply circuit;
- a first resistor coupled between the emitter of said first transistor and said second side of said current supply circuit;
- a plurality of transistors of the same geometry as said first transistor, each having its collector coupled to said start-up circuit and said first side of said current supply circuit;
- a plurality of resistors each of approximately the same resistance as said first resistor, individually coupled between the emitter of a respective one of said plurality of transistors and the emitter of said first transistor;
- a feedback circuit coupled to said start-up circuit, said first side of said current supply circuit, and said collectors of said plurality of transistors;
- said feedback circuit responsive to the difference between the total current flowing through said plurality of transistors and the current flowing through said first transistor for supplying a voltage to the bases of said plurality of transistors and said first transistor to reduce this difference in current to substantially zero;
- a compound darlington output circuit coupled to said first side of said current supply means for providing a stable temperature compensated reference voltage;
- a slow start and output inhibit circuit coupled to said second side of said current supply circuit, said compound darlington output circuit, said first side of said current supply circuit, and the collector of said first transistor which allows said reference voltage to be brought up to value at a specified rate;
- a pair of output resistors coupled to said compound darlington output circuit, said start-up circuit, said second side of said current supply circuit, and the bases of said first transistor and said plurality of transistors;
- and
- a pair of pull-up resistors capable of being coupled to said compound darlington output circuit;
- wherein said reference voltage is not substantially effected by thermally induced resistance variations in said first resistor and said plurality of resistors.
11 more elements
A temperature compensated reference voltage generator circuit comprising:
- a current supply circuit with a first and second side, said first side of said current supply circuit including a first transistor and a plurality of transistors;
- a start-up circuit coupled to said first side of said current supply circuit and said second side of said current supply circuit;
- a bandgap circuit further comprising:
- a second transistor coupled to said start-up circuit;
- a third transistor coupled to the base of said second transistor and the first side of said current supply circuit;
- a first resistor coupled to the emitters of said second and third transistors and said start-up circuit;
- a second resistor of approximately the same resistance as said first resistor coupled to said first resistor and said start-up circuit;
- a feedback circuit coupled to said bandgap circuit, said start-up circuit and said first side of said current supply circuit;
- said feedback circuit responsive to the difference between the total current flowing through said plurality of transistors and the current flowing through said first transistor for supplying a voltage to the bases of said plurality of transistors and said first transistor to reduce this difference in current to substantially zero;
- a compound darlington output circuit coupled to said bandgap circuit and said first side of said current supply circuit for providing a stable temperature compensated reference voltage;
- a slow start and output inhibit circuit coupled to said second side of said current supply circuit, said bandgap circuit, and said compound darlington output circuit which allows said reference voltage to be brought up to value at a specified rate;
- a pair of output resistors coupled to said second side of said current supply circuit, said bandgap circuit, and said compound darlington output circuit;
- wherein said reference voltage is not substantially effected by thermally induced resistance variations in said first resistor and said second resistor.
10 more elements
Dependencies are inferred from the claim text.