US-12619269-B2 - Integrated circuit temperature sensor with a reference voltage source pin

Abstract

A system, apparatus, and method for an integrated circuit (IC) temperature sensor having a reference voltage source pin is disclosed. The apparatus includes an integrated circuit temperature sensor including a sensing circuit; a reference voltage source to output a reference voltage; an operational amplifier coupled to the sensing circuit and the reference voltage source; an output voltage pin coupled to an output of the operational amplifier, the output voltage reflecting a difference between a voltage of the sensing circuit and the reference voltage; and a reference voltage source pin coupled to the reference voltage source.

Inventors

• Ashfaq Alan Juna
• Ezana Haile

Assignees

• MICROCHIP TOUCH SOLUTIONS LIMITED

Dates

Publication Date

20260505

Application Date

20240311

Claims (20)

1. 1 . An apparatus, comprising: an integrated circuit temperature sensor package including: a sensing circuit; a reference voltage source to output a reference voltage; an operational amplifier coupled to the sensing circuit and the reference voltage source; an output voltage pin coupled to an output of the operational amplifier, the output voltage reflecting a difference between a voltage of the sensing circuit and the reference voltage; and a reference voltage source pin coupled to the reference voltage source; wherein the output voltage pin and the reference voltage source pin are configured to be accessible by a device external to the integrated circuit temperature sensor package.
2. 2 . The apparatus of claim 1 , wherein the sensing circuit includes: a constant current source; and a diode.
3. 3 . The apparatus of claim 1 , the integrated circuit temperature sensor including a first resistor and a second resistor, wherein a gain of the operational amplifier is controlled by a resistance of the first resistor and a resistance of the second resistor.
4. 4 . The apparatus of claim 1 , the integrated circuit temperature sensor including a power supply input pin.
5. 5 . The apparatus of claim 1 , the integrated circuit temperature sensor including a power ground pin.
6. 6 . The apparatus of claim 1 , wherein an output voltage at the output voltage pin is proportional to a temperature of an environment around the integrated circuit temperature sensor.
7. 7 . A method comprising: measuring a reference voltage at a reference voltage pin of an integrated circuit temperature sensor package, the reference voltage pin accessible external to the integrated circuit temperature sensor package; measuring an output voltage at an output voltage pin of the integrated circuit temperature sensor package, the output voltage pin accessible external to the integrated circuit temperature sensor package; determining a difference between the output voltage and the reference voltage; and determining a temperature based on the difference between the output voltage and the reference voltage.
8. 8 . The method of claim 7 , comprising displaying the difference between the output voltage and the reference voltage.
9. 9 . The method of claim 7 , comprising outputting the temperature.
10. 10 . The method of claim 7 , comprising outputting the reference voltage to a control circuit.
11. 11 . The method of claim 7 , comprising outputting the difference between the output voltage and the reference voltage to a panel meter.
12. 12 . The method of claim 7 , comprising outputting the reference voltage to an analog to digital converter.
13. 13 . The method of claim 7 , comprising generating the reference voltage at the integrated circuit temperature sensor.
14. 14 . The method of claim 7 , wherein the output voltage is proportional to a temperature of an environment around the integrated circuit temperature sensor.
15. 15 . A system, comprising: an integrated circuit temperature sensor package including: a sensing circuit; a reference voltage source to output a reference voltage; an operational amplifier to output a voltage at an output voltage pin, the output voltage reflecting a difference between a voltage of the sensing circuit and the reference voltage; a reference voltage source pin coupled to the reference voltage source, wherein the output voltage pin and the reference voltage source pin are configured to be accessible by a device external to the integrated circuit temperature sensor package; and a control circuit to: measure the reference voltage at the reference voltage source pin of an integrated circuit temperature sensor; measure the output voltage at the output voltage pin of the integrated circuit temperature sensor; determine a difference between the output voltage and the reference voltage; and determine a temperature based on the difference between the output voltage and the reference voltage.
16. 16 . The system of claim 15 , the control circuit to output the difference between the output voltage and the reference voltage.
17. 17 . The system of claim 15 , the control circuit to output the temperature.
18. 18 . The system of claim 15 , the control circuit to output the reference voltage to an analog to digital converter.
19. 19 . The system of claim 15 , the integrated circuit temperature sensor to display the difference between the output voltage and the reference voltage.
20. 20 . The system of claim 15 , wherein the output voltage is proportional to a temperature of an environment around the integrated circuit temperature sensor.

Description

PRIORITY This application claims priority to U.S. Provisional Patent Application No. 63/615,101, filed Dec. 27, 2023, the contents of which are hereby incorporated in their entirety. TECHNICAL FIELD The present disclosure relates to temperature sensors, in particular, to an integrated circuit temperature sensor having a reference voltage source pin. BACKGROUND An integrated circuit (IC) temperature sensor may be built as a stand-alone semiconductor device or package in order to more easily deploy temperature sensors in a larger system, such as a circuit board, server, mobile phone, tablet, or other suitable electronic device or system. IC temperature sensors generate a reference voltage on the IC that corresponds to 0° Celsius. By measuring the output voltage of the IC temperature sensor and accounting for the reference voltage, the ambient temperature can be calculated. However, generation of the reference voltage is prone to errors caused by component tolerances and manufacturing defects. While manufacturing tolerances may be improved, doing so may result in increased manufacturing cost. Thus, there is a need for a temperature sensor to achieve higher accuracy without increasing manufacturing cost. SUMMARY OF THE INVENTION Aspects provide systems and methods for integrated circuit (IC) temperature sensor having a reference voltage source pin. An apparatus includes an integrated circuit temperature sensor including a sensing circuit; a reference voltage source to output a reference voltage; an operational amplifier coupled to the sensing circuit and the reference voltage source; an output voltage pin coupled to an output of the operational amplifier, the output voltage reflecting a difference between a voltage of the sensing circuit and the reference voltage; and a reference voltage source pin coupled to the reference voltage source. A method includes measuring a reference voltage at a reference voltage pin of an integrated circuit temperature sensor; measuring an output voltage at an output voltage pin of the integrated circuit temperature sensor; determining a difference between the output voltage and the reference voltage; and determining a temperature based on the difference between the output voltage and the reference voltage. A system includes an integrated circuit temperature sensor including a sensing circuit; a reference voltage source to output a reference voltage; an operational amplifier to output a voltage at an output voltage pin, the output voltage reflecting a difference between a voltage of the sensing circuit and the reference voltage; a reference voltage source pin coupled to the reference voltage source; and a control circuit to: measure a reference voltage at a reference voltage pin of an integrated circuit temperature sensor; measure an output voltage at an output voltage pin of the integrated circuit temperature sensor; determine a difference between the output voltage and the reference voltage; and determine a temperature based on the difference between the output voltage and the reference voltage. BRIEF DESCRIPTION OF THE DRAWINGS The figures illustrate examples of systems and methods. FIG. 1 illustrates an IC temperature sensor, according to examples of the present disclosure; FIG. 2 illustrates a method performed to determine a temperature using an IC temperature sensor, according to examples of the present disclosure; and FIG. 3 illustrates a system including an IC temperature sensor and a control circuit, according to examples of the present disclosure. The reference number for any illustrated element that appears in multiple different figures has the same meaning across the multiple figures, and the mention or discussion herein of any illustrated element in the context of any particular figure also applies to each other figure, if any, in which that same illustrated element is shown. DESCRIPTION According to an aspect of the invention, an integrated circuit (IC) temperature sensor having a reference voltage source pin is provided. The IC temperature sensor includes pins to allow for measurement of the reference voltage (Vref) and voltage output (Vout). By measuring both voltages, a voltage differential may be calculated and result in a more accurate temperature reading without requiring calibration of the IC temperature sensor. The term pin, as used herein, is not meant to be limited to any particular type of physical structure, and may include, without limitation, gull-wing or J-lead terminals, solder balls, or lands. FIG. 1 illustrates an IC temperature sensor, according to examples of the present disclosure. IC temperature sensor 100 may include Vout pin 110, Vref pin 120, sensing circuit 130, reference voltage source 140, operational amplifier 150, Vdd pin 160, Vss pin 170, first resistor R1, and second resistor R2. Sensing circuit 130 may generate a voltage or current proportional to a temperature within a defined operational range. Sensing circuit 130 may yield an output