Semiconductor device and data generation method

Patent metadata

Field	Value
Publication number	US-9360381-B2
Application number	US-201213439289-A
Country	US
Kind code	B2
Filing date	Apr 4, 2012
Priority date	Apr 13, 2011
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

A semiconductor device with improved temperature detection accuracy includes a coefficient calculation circuitry which calculates a plurality of N-th order coefficients, where N is an integer equal to or greater than one, of a correction function as an N-th order approximation of a characteristic function which relates temperature data measured by the temperature sensor and the actual temperature. The coefficient calculation circuitry uses N+1 pieces of the temperature data including a theoretical value at absolute zero in the characteristic function and N measured values of the temperature data measured by the temperature sensor unit at N points of temperature. A corrected temperatures are output using the correction function with the calculated coefficients and measured temperature values.

First claim

What is claimed is:

1. A semiconductor device comprising:
a temperature sensor circuit which detects a temperature of the semiconductor device and outputs temperature data based on the detected device temperature;
a coefficient calculation circuit which calculates a plurality of N-th order coefficients, where N is an integer equal to or greater than one, of a correction function as an N-th order approximation of a characteristic function which relates temperature data output by the temperature sensor circuit and the device temperature, based on N+1 pieces of the temperature data including a theoretical value of the temperature data at absolute zero in the characteristic function and N measured values of the temperature data output by the temperature sensor circuit at N temperature points;
a correction circuit which calculates and outputs a corrected device temperature using the correction function and the calculated N-th order coefficients on the basis of the temperature data outputted from the temperature sensor circuit; and
a central processing unit, coupled to the correction circuit, that controls an engine of a vehicle based on the corrected device temperature output by the correction circuit,
wherein the temperature sensor circuit generates the temperature data on the basis of a first voltage function having a limit at absolute zero which is zero, and a second voltage function having a limit at absolute zero which is non-zero, and
wherein the temperature data indicates a value corresponding to a ratio of the first voltage to the second voltage.

2. The semiconductor device according to claim 1 ,
wherein the temperature sensor circuit includes a plurality of bipolar transistors having mutually different emitter areas,
wherein the first voltage function corresponds to a difference between base-emitter voltages of two of the bipolar transistors, and the second voltage function corresponds to a forward voltage of a PN junction of the bipolar transistors.

3. The semiconductor device according to claim 1 ,
wherein the correction operation circuit comprises an exclusive logic circuit.

4. The semiconductor device according to claim 3 ,
wherein the coefficient calculation circuit comprises an exclusive logic circuit.

5. The semiconductor device according to claim 1 ,
wherein the correction operation circuit switches the N-th order coefficients depending on a temperature range of the temperature data.

6. The semiconductor device according to claim 5 ,
wherein the correction operation circuit switches the N-th order coefficients in a higher temperature range and a lower temperature range with reference to a predetermined temperature in the temperature range of required measurement temperature.

7. The semiconductor device according to claim 1 ,
wherein the temperature sensor circuit comprises:
a temperature-voltage conversion circuit to output first voltages of the first voltage function and second voltages of the second voltage function; and
an analog-to-digital conversion circuit to sample the first voltages and the second voltages via two sampling capacitors, and to generate the temperature data.

8. The semiconductor device according to claim 7 ,
wherein one end of each of the two sampling capacitors is set to a reference potential of the temperature-voltage conversion circuit, and
wherein the other end of the two sampling capacitors are respectively supplied with one of the first voltages or one of the second voltages when sampling and set to the reference potential of the temperature-voltage conversion circuit when refreshing.

9. The semiconductor device according to claim 7 ,
wherein the temperature sensor circuit further comprises:
a first signal line through which the first voltages are supplied;
a second signal line through which the second voltages are supplied;
a first shielding wire operable to shield the first signal line; and
a second shielding wire operable to shield the second signal line, and
wherein the first shielding wire and the second shielding wire are set to the reference potential of the temperature-voltage conversion circuit.

10. The semiconductor device according to claim 7 ,
wherein the temperature sensor circuit further comprises:
a first selection circuit operable to switch from the first voltages and the second voltages to respective external input voltages in response to a selection signal, and to output to the analog-to-digital conversion circuit.

11. The semiconductor device according to claim 10 ,
wherein the temperature sensor circuit further comprises:
a second selection circuit operable to switch an output destination of the temperature data generated by the analog-to-digital conversion circuit, and
wherein the second selection circuit outputs the temperature data to either of an input signal line or an output signal line of the correction operation circuit, in response to the selection signal inputted.

12. A method to correct temperature data of a semiconductor device comprising:
detecting a temperature of the semiconductor device, by a temperature sensor circuit;
generating the temperature data based on the detected temperature of the semiconductor device, by the temperature sensor circuit;
calculating a plurality of N-th order coefficients of a correction function as an N-th order approximation, where N is an integer equal to or greater than one, of a characteristic function which relates the temperature data generated by the temperature sensor circuit and the temperature of the semiconductor device, based on N+1 pieces of the temperature data including a theoretical value of the temperature data at absolute zero in the characteristic function and N measured values of the temperature data output by the temperature sensor circuit at N temperature points; and
calculating a corrected temperature of the semiconductor device using the correction function and the calculated N-th order coefficients on the basis of the measured temperature data outputted from the temperature sensor circuit; and
outputting the corrected temperature to a central processing unit that controls an engine of a vehicle based on the corrected temperature of the semiconductor device,
wherein the temperature sensor circuit generates the temperature data on the basis of a first voltage function having a limit at absolute zero which is zero, and a second voltage function having a limit at absolute zero which is non-zero,
wherein the temperature data indicates a value corresponding to a ratio of the first voltage to the second voltage.

13. The method to correct temperature data according to claim 12 ,
wherein the first voltage function corresponds to a forward voltage of a PN junction of the temperature sensor circuit, and
wherein the second voltage function corresponds to a difference between respective base-emitter voltages of two bipolar transistors having mutually different emitter areas of the temperature sensor circuit.

Assignees

• Arisaka Naoya
• Ito Takayasu
• Horiguchi Masashi
• Renesas Electronics Corp

Inventors

• Arisaka Naoya
• Ito Takayasu
• Horiguchi Masashi

Classifications

• G01K15/005 Primary

  Calibration · CPC title

• G01K7/01

  using semiconducting elements having PN junctions (G01K7/02, G01K7/16, G01K7/30 take precedence) · CPC title

• G05F3/30

  Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities (G05F3/26 takes precedence) · CPC title