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US 10,295,416 B2Granted
Temperature sensing circuit with temperature coefficient estimation and compensation using time variable substrate heating
AssigneeSTMicroelectronics International N.V.
InventorsPratap Narayan Singh, Nitin Bansal
Life of this patent
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Abstract
A localized substrate heater is configured to apply variable substrate heating to an integrated bipolar transistor. The base-to-emitter voltage (Vbe) of that bipolar transistor at varying substrate temperature settings is sensed, with the sensed Vbe processed to determine temperature coefficients of the bipolar transistor. The bipolar transistor may, for example, be a circuit component of an integrated temperature sensing circuit.
Claims29
An integrated circuit, comprising:
- a semiconductor substrate;
- and
- a temperature sensitive circuit integrated on and in said substrate, said temperature sensitive circuit including:
- a first current source configured to generate a first current;
- a first bipolar transistor configured as a diode-connected device and biased by said first current to exhibit a first base-to-emitter (Vbe) voltage;
- wherein said first bipolar transistor is located in a portion of said semiconductor substrate;
- a substrate heating circuit configured to heat said portion of semiconductor substrate in response to a temperature control signal;
- an analog-to-digital converter (ADC) circuit having an input coupled to the first bipolar transistor and configured to convert the first Vbe voltage to a first digital signal;
- and
- a digital control circuit configured to generate said temperature control signal and cause the substrate heating circuit to heat said portion to two different temperatures, receive the first digital signal from said ADC circuit in response to heating at each of said two different temperatures, and process said first digital signals for the first Vbe voltage at each of said two different temperatures to calculate temperature coefficients of operation of said first bipolar transistor by numerically solving at least two linear equations respectively set equal to the first digital signals, where each linear equation has the temperature coefficients of operation as unknowns.
7 more elements
A method, comprising:
- heating a portion of a semiconductor substrate to at least two different temperatures, wherein said portion includes a first bipolar transistor configured as a diode-connected device and biased by a first current to exhibit a first base-to-emitter (Vbe) voltage;
- sensing the first Vbe voltage at each of the at least two different temperatures;
- converting the sensed first Vbe voltages to corresponding first digital signals;
- processing said first digital signals for the first Vbe voltages at each of said two different temperatures to calculate temperature coefficients of operation of said first bipolar transistor by numerically solving at least two linear equations respectively set equal to the first digital signals, where each linear equation has the temperature coefficients of operation as unknowns.
1 more element
An integrated circuit, comprising:
- a semiconductor substrate;
- and
- a temperature sensitive circuit integrated on and in said substrate, said temperature sensitive circuit including:
- a first current source configured to generate a first current;
- a first bipolar transistor configured as a diode-connected device and biased by said first current to exhibit a first base-to-emitter (Vbe) voltage;
- wherein said first bipolar transistor is located in a portion of said semiconductor substrate;
- a substrate heating circuit configured to heat said portion of semiconductor substrate in response to a temperature control signal;
- an analog-to-digital converter (ADC) circuit having an input coupled to the first bipolar transistor and configured to convert the first Vbe voltage to a first digital signal;
- a switching circuit including a first switch that when actuated supplies said ADC circuit with a reference voltage derived from an off-chip accurate voltage supply;
- and
- a digital control circuit configured to operate in a calibration mode to:
- actuate the first switch, generate said temperature control signal to cause the substrate heating circuit to heat said portion to two different temperatures, and receive the first digital signal from said ADC circuit in response to heating at each of said two different temperatures.
9 more elements
A method, comprising:
- heating a portion of a semiconductor substrate to at least two different temperatures, wherein said portion includes a first bipolar transistor configured as a diode-connected device and biased by a first current to exhibit a first base-to-emitter (Vbe) voltage;
- sensing the first Vbe voltage at each of the at least two different temperatures;
- converting the sensed Vbe voltages to corresponding first digital signals, wherein converting comprises analog to digital converting with respect to a reference voltage, wherein said reference voltage is derived from an off-chip accurate voltage supply;
- and
- processing said first digital signals for the first Vbe voltages at said at least two different temperatures to calculate temperature coefficients of operation of said first bipolar transistor.
2 more elements
Dependencies are inferred from the claim text.