Fast start-up low-voltage bandgap voltage reference circuit
First Claim
1. A bandgap voltage reference circuit, said circuit comprising:
- a first current generator for generating a first reference current with positive temperature coefficient, said first current generator having a self-bias circuit, and a node which outputs a node voltage with negative temperature coefficient;
a second current generator having a voltage-controlled current source receiving said node voltage for generating a second reference current with negative temperature coefficient according to the node voltage; and
an output resistor accepting both the first reference current and the second reference current for outputting a bandgap voltage according to the first reference current and the second reference current;
wherein the self-bias circuit further comprises;
a first transistor having a first gate and a first drain;
a second transistor having a second drain and a second gate, the second gate being coupled to the first gate;
a first amplifier having a first input end, a second input end and an output end, said output end being coupled to both gates of the first and the second transistors, the first input end and the second input end being coupled to the drains of the first and the second transistors respectively;
a third transistor having a third emitter thereof coupled to the first input end of the first amplifier;
a first resistor coupled to the second input end of the first amplifier; and
a fourth transistor having a fourth emitter thereof coupled to the first resistor, wherein the node is coupled to the fourth emitter of the fourth transistor.
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Abstract
A fast start-up low-voltage bandgap voltage reference circuit is disclosed. The bandgap voltage reference circuit includes: a first current generator, which is implemented by a self-bias unit and a current mirror for generating a first reference current with positive temperature coefficient; a second current generator, which is connected to a point with negative temperature coefficient in the first current generator to generate a second reference current with negative temperature coefficient; and a resistor for converting the first reference current and the second reference current into a low-voltage bandgap voltage independent of temperature. Because the bandgap voltage reference circuit of the invention uses the resistor to convert the first reference current and the second reference current into voltage, the circuit can provide low-voltage bandgap voltage.
81 Citations
14 Claims
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1. A bandgap voltage reference circuit, said circuit comprising:
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a first current generator for generating a first reference current with positive temperature coefficient, said first current generator having a self-bias circuit, and a node which outputs a node voltage with negative temperature coefficient;
a second current generator having a voltage-controlled current source receiving said node voltage for generating a second reference current with negative temperature coefficient according to the node voltage; and
an output resistor accepting both the first reference current and the second reference current for outputting a bandgap voltage according to the first reference current and the second reference current;
wherein the self-bias circuit further comprises;
a first transistor having a first gate and a first drain;
a second transistor having a second drain and a second gate, the second gate being coupled to the first gate;
a first amplifier having a first input end, a second input end and an output end, said output end being coupled to both gates of the first and the second transistors, the first input end and the second input end being coupled to the drains of the first and the second transistors respectively;
a third transistor having a third emitter thereof coupled to the first input end of the first amplifier;
a first resistor coupled to the second input end of the first amplifier; and
a fourth transistor having a fourth emitter thereof coupled to the first resistor, wherein the node is coupled to the fourth emitter of the fourth transistor. - View Dependent Claims (2, 3, 4, 5)
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6. A circuit for generating a bandgap voltage, said circuit comprising:
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a bandgap reference circuit for generating a first reference current with positive temperature coefficient, wherein the bandgap reference circuit includes a node for outputting a node voltage with negative temperature coefficient;
a voltage-controlled current source coupled to the node for producing a second reference current with negative temperature coefficient according the node voltage;
a current mirror coupled to the voltage-controlled current source for outputting the second reference current;
an output resistor, said output resistor accepting both the first reference current and the second reference current for outputting the bandgap voltage according to the first and second reference currents;
a first transistor having a first gate thereof coupled to the band gap reference circuit;
a second transistor having a second drain thereof coupled to the first gate of the first transistor; and
a starting circuit coupled to the first and the second transistors for controlling the second transistor according to a current received from the first transistor. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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13. A circuit for generating a bandgap voltage, said circuit comprising:
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a first current generator for generating a first reference current with positive temperature coefficient, wherein the first current generator includes a node for outputting a node voltage with negative temperature coefficient;
a voltage-controlled current source coupled to the node for producing a second reference current with negative temperature coefficient according the node voltage;
an output resistor, said output resistor accepting both the first reference current and the second reference current for outputting the bandgap voltage according to the first and second reference currents;
a first transistor having a first gate thereof coupled to the first current generator;
a second transistor having a second drain thereof coupled to the first gate of the first transistor; and
a starting circuit coupled to the first and the second transistors for controlling the second transistor according to a current received from the first transistor. - View Dependent Claims (14)
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Specification