Temperature-compensated current monitoring
View Patent ↗Systems, methods and media for current monitoring are provided herein. An exemplary method may include: receiving a temperature of a power MOSFET, the temperature being sensed by a temperature sensor; determining a resistance of the power MOSFET using the received temperature; receiving a voltage across the power MOSFET, the voltage being measured by a differential amplifier; calculating a current provided to an electrical load by the power MOSFET using the determined resistance of the power MOSFET and the received voltage; comparing the calculated current to a predetermined threshold; and switching the power MOSFET to an off state in response to the calculated current exceeding the predetermined threshold.
1. A system for monitoring current comprising:
an electrical load;
a power MOSFET electrically coupled to the electrical load;
a differential amplifier electrically coupled to the power MOSFET;
a temperature sensor thermally coupled to the power MOSFET;
a processor communicatively coupled to the differential amplifier and the temperature sensor; and
a memory communicatively coupled to the processor, the memory storing instructions executable by the processor to perform a method comprising:
receiving a temperature of the power MOSFET, the temperature being sensed by the temperature sensor, the receiving the temperature of the power MOSFET including:
receiving an analog voltage from the temperature sensor, the analog voltage representing the temperature of the power MOSFET, and
converting the analog voltage to a digital number by an analog to digital converter, the digital number representing the temperature of the power MOSFET,
determining a resistance of the power MOSFET using the digital number representing the temperature,
receiving a voltage across the power MOSFET, the voltage being measured by the differential amplifier,
calculating a current provided to the electrical load by the power MOSFET using the determined resistance of the power MOSFET and the received voltage,
comparing the calculated current to a predetermined threshold, and
switching the power MOSFET to an off state in response to the calculated current exceeding the predetermined threshold.
2. The system of claim 1 further comprising:
a display, the display providing a notification to a user.
3. The system of claim 1 further comprising:
a substrate, the power MOSFET and the temperature sensor being disposed on the substrate.
4. The system of claim 1 further comprising:
a heat sink, the heatsink being thermally coupled to the power MOSFET and the temperature sensor.
5. The system of claim 1 wherein the method further comprises:
providing a notification to a user in response to the calculated current exceeding the predetermined threshold, the notification directing the user to service the electrical load.
6. The system of claim 1 wherein the power MOSFET is an n-type MOSFET.
7. The system of claim 6 wherein the power MOSFET is in a high-side configuration.
8. The system of claim 1 wherein the power MOSFET is a p-type MOSFET.
9. The system of claim 1 wherein the differential amplifier is a single-ended non-inverting op-amp operating.
10. The system of claim 1 wherein the differential amplifier is at least one of a current shunt monitor (CSM), difference amplifier (DA), and instrumentation amplifier (IA).
11. The system of claim 1 wherein the temperature sensor is an integrated silicon-based sensor.
12. The system of claim 1 wherein the temperature sensor is at least one of a thermocouple, resistive temperature device (RTD), and thermistor.
13. A method for current monitoring by a processor comprising:
receiving a temperature of a power MOSFET, the temperature being sensed by a temperature sensor, the receiving the temperature of the power MOSFET including:
receiving an analog voltage from the temperature sensor, the analog voltage representing the temperature of the power MOSFET, and
converting the analog voltage to a digital number by an analog to digital converter, the digital number representing the temperature of the power MOSFET;
determining a resistance of the power MOSFET using the digital number representing the temperature;
receiving a voltage across the power MOSFET, the voltage being measured by a differential amplifier;
calculating a current provided to an electrical load by the power MOSFET using the determined resistance of the power MOSFET and the received voltage;
comparing the calculated current to a predetermined threshold; and
switching the power MOSFET to an off state in response to the calculated current exceeding the predetermined threshold.
14. The method of claim 13 wherein determining the resistance of the power MOSFET includes using the digital number representing the temperature to evaluate a second order polynomial.
15. The method of claim 13 wherein calculating the current includes using the determined resistance of the power MOSFET and the received voltage to evaluate Ohm's Law.
16. The method of claim 13 further comprising:
providing a notification to a user in response to the calculated current exceeding the predetermined threshold, the notification directing the user to service the electrical load.
17. A system for monitoring current comprising:
an electrical load;
a power MOSFET electrically coupled to the electrical load;
a differential amplifier electrically coupled to the power MOSFET;
a temperature sensor thermally coupled to the power MOSFET;
a processor communicatively coupled to the differential amplifier and the temperature sensor; and
a memory communicatively coupled to the processor, the memory storing instructions executable by the processor to perform a method comprising:
receiving a temperature of the power MOSFET, the temperature being sensed by the temperature sensor,
determining a resistance of the power MOSFET using the received temperature,
receiving a voltage across the power MOSFET, the voltage being measured by the differential amplifier, the receiving the voltage across the power MOSFET including:
receiving an analog voltage from the differential amplifier, the analog voltage representing the temperature of the power MOSFET, and
converting the analog voltage to a digital number by an analog to digital converter, the digital number representing the voltage across the power MOSFET,
calculating a current provided to the electrical load by the power MOSFET using the determined resistance of the power MOSFET and the digital number representing the voltage,
comparing the calculated current to a predetermined threshold, and
switching the power MOSFET to an off state in response to the calculated current exceeding the predetermined threshold.
18. The system of claim 17 further comprising:
a display, the display providing a notification to a user.
19. The system of claim 17 further comprising:
a substrate, the power MOSFET and the temperature sensor being disposed on the substrate.
20. The system of claim 17 further comprising:
a heat sink, the heat sink being thermally coupled to the power MOSFET and the temperature sensor.
21. The system of claim 17 wherein the method further comprises:
providing a notification to a user in response to the calculated current exceeding the predetermined threshold, the notification directing the user to service the electrical load.
22. The system of claim 17 wherein the power MOSFET is an n-type MOSFET.
23. The system of claim 22 wherein the power MOSFET is in a high-side configuration.
24. The system of claim 17 wherein the power MOSFET is a p-type MOSFET.
25. The system of claim 17 wherein the differential amplifier is a single-ended non-inverting op-amp operating.
26. The system of claim 17 wherein the differential amplifier is at least one of a current shunt monitor (CSM), difference amplifier (DA), and instrumentation amplifier (IA).
27. The system of claim 17 wherein the temperature sensor is at least one of an integrated silicon-based sensor, thermocouple, resistive temperature device (RTD), and thermistor.
28. A method for current monitoring by a processor comprising:
receiving a temperature of a power MOSFET, the temperature being sensed by a temperature sensor;
determining a resistance of the power MOSFET using the received temperature;
receiving a voltage across the power MOSFET, the voltage being measured by a differential amplifier, the receiving the voltage across the power MOSFET including:
receiving an analog voltage from the differential amplifier, the analog voltage representing the temperature of the power MOSFET, and
converting the analog voltage to a digital number by an analog to digital converter, the digital number representing the voltage across the power MOSFET;
calculating a current provided to an electrical load by the power MOSFET using the determined resistance of the power MOSFET and the digital number representing the voltage;
comparing the calculated current to a predetermined threshold; and
switching the power MOSFET to an off state in response to the calculated current exceeding the predetermined threshold.
29. The method of claim 28 wherein determining the resistance of the power MOSFET includes using the received temperature to evaluate a second order polynomial.
30. The method of claim 28 wherein calculating the current includes using the determined resistance of the power MOSFET and the digital number representing the voltage to evaluate Ohm's Law.