BANDGAP REFERENCE CIRCUITS
First Claim
1. A bandgap reference circuit, comprising:
- a current mirror comprising a control terminal, a first output terminal and a second output terminal;
an operational amplifier comprising an output terminal coupled to the control terminal of the current mirror, and first and second input terminals;
a first resistor coupled between the first output terminal of the current mirror and the first input terminal of the operational amplifier;
a second resistor coupled between the first output terminal of the current mirror and the second input terminal of the operational amplifier;
a third resistor comprising a first terminal coupled to the first input terminal of the operational amplifier, and a second terminal;
a first transistor coupled between the second terminal of the third resistor and a ground voltage;
a second transistor coupled between the ground voltage and the second input terminal of the operational amplifier; and
a fourth resistor coupled between the ground voltage and the second output terminal of the current mirror.
1 Assignment
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Accused Products
Abstract
Bandgap reference circuits capable operating in low voltage environments. In the bandgap reference circuit, a current generation circuit generates an output current obtained by combining a first current, a second current and a third current. The first current is converted from a first voltage and a first forward voltage of a first constant voltage generation element. The second current and the third current are both converted from a voltage difference between the first forward voltage and a second forward voltage of the second constant voltage generation element. A current-to-voltage generator converts the output current to an output voltage.
16 Citations
22 Claims
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1. A bandgap reference circuit, comprising:
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a current mirror comprising a control terminal, a first output terminal and a second output terminal;
an operational amplifier comprising an output terminal coupled to the control terminal of the current mirror, and first and second input terminals;
a first resistor coupled between the first output terminal of the current mirror and the first input terminal of the operational amplifier;
a second resistor coupled between the first output terminal of the current mirror and the second input terminal of the operational amplifier;
a third resistor comprising a first terminal coupled to the first input terminal of the operational amplifier, and a second terminal;
a first transistor coupled between the second terminal of the third resistor and a ground voltage;
a second transistor coupled between the ground voltage and the second input terminal of the operational amplifier; and
a fourth resistor coupled between the ground voltage and the second output terminal of the current mirror. - View Dependent Claims (2, 3, 4, 5)
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6. A bandgap reference circuit, comprising:
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a current mirror comprising a control terminal, a first output terminal and a second output terminal;
an operational amplifier comprising an output terminal coupled to control terminal of the current mirror, and first and second input terminals;
a first resistor coupled between the first output terminal of the current mirror and the first input terminal of the operational amplifier;
a second resistor coupled between the first output terminal of the current mirror and the second input terminal of the operational amplifier;
a third resistor comprising a first terminal coupled to the first input terminal of the operational amplifier, and a second terminal;
a first transistor coupled between the second terminal of the third resistor and a ground voltage;
a second transistor coupled between the ground voltage and the second input terminal of the operational amplifier; and
a fourth resistor coupled between the first output terminal and the second output terminal of the current mirror. - View Dependent Claims (7, 8, 9, 10)
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11. A bandgap reference circuit, comprising:
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a first MOS transistor coupled between a power voltage and a first node;
a second MOS transistor coupled between the power voltage and an output terminal;
an operational amplifier comprising an output terminal coupled to the first and the second MOS transistors;
a first resistor coupled between the first node and the operational amplifier;
a second resistor coupled between the first node and the operational amplifier;
a third resistor coupled to the first resistor and the operational amplifier;
a first transistor coupled between the third resistor and a ground voltage;
a second transistor coupled between the ground voltage and the second resistor;
a fourth resistor coupled to the first node; and
a fifth resistor coupled between the output terminal and the ground voltage. - View Dependent Claims (12, 13)
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14. A bandgap reference circuit, comprising:
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a current mirror, in response to a control signal, producing a first current mirror output and a second current mirror output through a first output terminal and a second output terminal respectively, wherein the first current mirror output comprises first and second currents with positive temperature coefficient and a third current with negative temperature coefficient;
a first resistor coupled between the first output terminal and a first node, receiving the first current;
a second resistor coupled between the first output terminal and a second node, receiving the second current;
an operational amplifier coupled to the first node and the second node, generating the control signal to control the current mirror according to voltages on the first and second nodes;
a third resistor comprising a first terminal coupled to the first input terminal of the operational amplifier, and a second terminal;
a first transistor coupled between the second terminal of the third resistor and a ground voltage;
a second transistor coupled between the ground voltage and the second node; and
a fourth resistor coupled to the first output terminal, receiving the third current. - View Dependent Claims (15, 16, 17)
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18. A bandgap reference circuit, comprising:
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a current generation circuit, generating an output current obtained by combining a first current, a second current and a third current, wherein the first current is converted from a first voltage and a first forward voltage of a first constant voltage generation element, and the second current and the third current are both converted from a voltage difference between the first forward voltage and a second forward voltage of the second constant voltage generation element; and
a current-to-voltage generator, converting the output current to an output voltage. - View Dependent Claims (19, 20, 21)
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22. A bandgap reference circuit, comprising:
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a current generation circuit, generating an output current obtained by combining a first current, a second current and a third current, wherein the first current is converted from a first voltage and a first forward voltage of a first constant voltage generation element, the first voltage and the first forward voltage form a node voltage, the second current is converted from a voltage difference between the node voltage and the second forward voltage, and the third current is converted from a voltage difference between the first forward voltage and a second forward voltage of the second constant voltage generation element; and
a current-to-voltage generator, converting the output current to an output voltage.
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Specification