Temperature correction circuit for a reference voltage
AssigneeNXP USA, Inc.
InventorJohn Pigott
Life of this patent
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Abstract
A temperature correction circuit for a voltage reference circuit includes two amplifiers, each having an output that controls a respective transistor that produces correction current for adjusting the reference voltage. Both amplifiers include one input coupled in a path to a reference voltage source and another input coupled in a path to a temperature sensing diode circuit. One amplifier's output controls the conductivity of its respective transistor to adjust the reference voltage when the temperature exceeds a high temperature set point. The other amplifier's output controls the conductivity of its respective transistor to adjust the reference voltage when the temperature falls below a low temperature set point.
Claims24
A circuit, comprising:
- a reference voltage source;
- an output coupled to the reference voltage source, the output for providing a reference voltage;
- a temperature sensing diode circuit;
- a first amplifier having a first input coupled in a path to the reference voltage source and a second input coupled in a path to a terminal of the temperature sensing diode circuit;
- a first transistor including a control terminal coupled to an output of the first amplifier and a first current terminal to provide a correction current for adjusting the reference voltage in response to the temperature sensing diode circuit indicating that a first temperature is being exceeded;
- a second amplifier including a first input coupled in a path to the reference voltage source and a second input coupled in a path to the terminal of the temperature sensing diode circuit;
- a second transistor including a control terminal coupled to an output of the second amplifier and a first current terminal for providing a correction current for adjusting the reference voltage in response to the temperature sensing diode circuit indicating that the temperature is below a second temperature.
A circuit, comprising:
- a reference voltage source;
- an output path from the reference voltage source to a power supply rail;
- an output connected to a node of the output path for providing a reference voltage;
- a temperature sensing diode circuit;
- a first amplifier having a first input coupled in a path to the reference voltage source and a second input coupled in a path to a terminal of the temperature sensing diode circuit;
- a first transistor including a control terminal coupled to an output of the first amplifier and a first current terminal to provide a correction current for adjusting the reference voltage in response to the temperature sensing diode circuit indicating that a first temperature is being exceeded;
- a second amplifier including a first input coupled in a path to the reference voltage source and a second input coupled in a path to the terminal of the temperature sensing diode circuit;
- a second transistor including a control terminal coupled to an output of the second amplifier and a first current terminal for providing a correction current for adjusting the reference voltage in response to the temperature sensing diode circuit indicating that the temperature is below a second temperature;
- wherein a second current terminal of the first amplifier is coupled to the first input of the first amplifier;
- wherein a second current terminal of the second transistor is coupled to the second input of the second transistor.
Dependencies are inferred from the claim text.