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US 12,591,263 B2Granted
Voltage and current reference circuits providing voltage and currents with near zero temperature coefficients
AssigneeSilicon Laboratories Inc.
InventorAbdulkerim Coban
Life of this patent
Estimating the term…
Abstract
A voltage reference circuit can operate in a large supply voltage range, including a low supply voltage, and can operate with high PSRR. The voltage reference circuit supplies a voltage reference with a near zero temperature coefficient (TC) across a wide-temperature range. The voltage reference circuit develops a first current with a positive temperature coefficient from a first transistor and a second current with a negative temperature coefficient from a second transistor. The control terminals of the two transistors are supplied by respective outputs of two error amplifiers. The two currents are combined to develop a voltage reference across a resistor. The voltage reference has a near zero temperature coefficient.
Claims20
A voltage reference circuit comprising:
- a first amplifier;
- a second amplifier;
- a first transistor of a first conductivity type having first and second current terminals coupled between a first supply voltage node and an output node, and having a control terminal coupled to an output of the first amplifier;
- a second transistor of the first conductivity type having first and second current terminals coupled between the first supply voltage node and the output node, and having a gate terminal coupled to an output of the second amplifier;
- a first resistor coupled between the output node and a second supply voltage node;
- a first transistor of a second conductivity type having first and second current terminals coupled between the second supply voltage node and a first intermediate node, and having a control terminal coupled to a second intermediate node;
- a second transistor of the second conductivity type having first and second current terminals coupled between the second supply voltage node and a third intermediate node and having a control terminal coupled to the third intermediate node;
- at least a second resistor coupled between the first intermediate node and the second intermediate node;
- wherein the first amplifier has a first input coupled to the first intermediate node and has a second input coupled to the third intermediate node;
- wherein a first current supplied by the first transistor to the first resistor has a positive temperature coefficient;
- wherein a second current supplied by the second transistor to the first resistor has a negative temperature coefficient;
- and
- wherein the first current and the second current combine to generate an output voltage across the first resistor.
10 more elements
A method for providing a voltage reference from a voltage reference circuit comprising:
- supplying respective control terminals of a first transistor and a second transistor with a first voltage present on an output of a first amplifier;
- supplying a first current from the first transistor to a first resistor;
- supplying a second current from the second transistor that is proportional to a voltage on a first input terminal of the first amplifier divided by a resistance value of the first resistor, the second current having a negative temperature coefficient;
- supplying a control terminal of a third transistor with a second voltage present on an output of a second amplifier and supplying a third current having a positive temperature coefficient from the third transistor;
- supplying the second current and the third current to a second resistor to generate the voltage reference with a near zero temperature coefficient;
- and
- supplying a control terminal of a fourth transistor with a voltage present on a first input of the second amplifier.
4 more elements
A reference circuit comprising:
- a first transistor having first and second current terminals coupled between a first supply voltage node and an output node supplying a voltage reference, the first transistor having a control terminal coupled to an output of a first amplifier;
- a second transistor having first and second current terminals coupled between the first supply voltage node and the output node, and having a control terminal coupled to an output of a second amplifier;
- a first resistor coupled between the output node and a second supply voltage node;
- a third transistor having first and second current terminals coupled between the second supply voltage node and a first intermediate node, and having a control terminal coupled to a second intermediate node;
- a fourth transistor having first and second current terminals coupled between the second supply voltage node and a third intermediate node and having a control terminal coupled to the third intermediate node;
- a second resistor coupled between the first intermediate node and the second intermediate node;
- wherein the first amplifier has a first input coupled to the first intermediate node and has a second input coupled to the third intermediate node;
- wherein a first current supplied by the first transistor to the first resistor has a positive temperature coefficient;
- wherein a second current supplied by the second transistor to the first resistor has a negative temperature coefficient;
- and
- wherein the first current and the second current combine to generate the voltage reference across the first resistor, the voltage reference having a near zero temperature coefficient.
8 more elements
Dependencies are inferred from the claim text.