Control of voltage regulator thermal condition
View Patent ↗A system and method for automatically adjusting microprocessor activity following thermal stress of a voltage regulator is disclosed. A thermal monitoring circuit determines whether the voltage regulator has exceeded a predetermined temperature. The thermal monitoring circuit may employ a temperature-sensing component such as a thermistor to determine the temperature or may derive the temperature indirectly, based on the average input (or output) current. When the over-temperature condition occurs, a signal activates the PROCHOT#, or similar, pin on a microprocessor, throttling the microprocessor clock. Where the microprocessor includes no internal power-reducing feature, the signal throttles an external clock coupled to the microprocessor. In either case, execution of the microprocessor is slowed down. At all times, the voltage regulator maintains the ability to supply continuous current to the microprocessor.
1. A system comprising:
a voltage regulator for supplying a voltage to a microprocessor, the voltage regulator comprising a location; and
a circuit coupled to the location, the circuit comprising:
a thermistor and a first resistor coupled to the location, the thermistor and the first resistor establishing a voltage;
a pair of resistors coupled between a source voltage and a ground, the pair of resistors supplying a reference voltage; and
a comparator for receiving the voltage and the reference voltage; wherein the circuit:
issues a throttle signal to a clock, the clock controlling the rate at which instructions are executed by the microprocessor, wherein the throttle signal is issued from the comparator when the voltage exceeds the reference voltage.
2. The system of claim 1 , wherein the clock is internal to the microprocessor and the throttle signal activates a prochot# or similar pin of the microprocessor.
3. The system of claim 1 , wherein the clock is external to the microprocessor and the throttle signal slows down the external clock.
4. The system of claim 1 , the voltage regulator further comprising an input current, wherein the location is coupled to the input current.
5. The system of claim 1 , the voltage regulator further comprising an output current, wherein the location is coupled to the output current.
6. A system comprising:
a voltage regulator for supplying a voltage to a microprocessor, the voltage regulator comprising a location; and
a circuit coupled to the location, the circuit comprising an op amp comprising a first input and a second Input, the first input being coupled to a first resistor and a second resistor, the first resistor being coupled to a voltage source and the second resistor being coupled to ground, the pair of resistors providing a reference voltage to the op amp, the second input being coupled to a thermistor, wherein the op amp produces a throttle signal when a resistance of the thermistor drops below the resistance of the second resistor;
wherein the throttle signal is issued to a clock, the clock controlling the rate at which instructions are executed by the microprocessor.
7. The system of claim 6 , wherein the thermistor tracks current flowing through a field-effect transistor within the circuit.
8. The system of claim 6 , wherein the thermistor tracks current flowing through an inductor within the circuit.
9. The system of claim 7 , wherein the clock is internal to the microprocessor and the throttle signal is coupled to a prochot# or similar pin of the microprocessor.
10. The system of claim 7 , wherein the clock is external to the microprocessor.
11. The system of claim 8 , wherein the clock is internal to the microprocessor and the throttle signal is coupled to a prochot# or similar pin of the microprocessor.
12. The system of claim 8 , wherein the clock is external to the microprocessor.
13. The system of claim 6 , the voltage regulator further comprising an input current, wherein the location is coupled to the input current.
14. The system of claim 6 , the voltage regulator further comprising an output current, wherein the location is coupled to the output current.
15. The system of claim 13 , wherein the circuit further comprises a transistor in which current passing through the transistor produces a voltage that is proportional to the average output current, wherein the circuit sends a signal to the microprocessor when the voltage across the transistor exceeds a predetermined voltage.
16. The system of claim 12 , wherein the circuit activates the power-reducing feature of the microprocessor coupled to the voltage regulator by throttling a clock external to the microprocessor.
17. The system of claim 16 , wherein the circuit further comprises an inductor whose voltage is proportional to the average output current, wherein the circuit sends a signal to the clock when the voltage across the inductor exceeds a predetermined voltage.
18. The system of claim 16 , wherein the circuit further comprises a transistor in which current passing through the transistor produces a voltage that is proportional to the average output current, wherein the circuit sends a signal to the dock when the voltage across the transistor exceeds a predetermined voltage.