# US 8,788,866 B2 · Method and system for reducing thermal load by monitoring and controlling current flow in a portable computing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,788,866 B2 - Document ID: US8788866B2 - Status: Granted - Kind: B2 - Application number: 13/197,238 - Filed: 2011-08-03 - Published: 2012-10-25 - Granted: 2014-07-22 - Earliest claimed: 2011-04-25 - Assignees: QUALCOMM Incorporated - Applicants: Jon James Anderson; Gary D. Good - Inventors: Jon James Anderson; Gary D. Good - Web page: https://patentgrep.com/patent/US8788866B2 ## CPC - G06F 1/206: {comprising thermal management} - G06F 1/28: Supervision thereof, e.g. detecting power-supply failure by out of limits supervision - G06F 1/324: by lowering clock frequency - G06F 1/3287: by switching off individual functional units in the computer system - G06F 1/3296: by lowering the supply or operating voltage - G06F 11/3058: {Monitoring arrangements for monitoring environmental properties or parameters of the computing system or of the computing system component, e.g. monitoring of power, currents, temperature, humidity, position, vibrations (thermal management in cooling arrangements of a computing system G06F1/206)} - Y02D 10/00: Energy efficient computing, e.g. low power processors, power management or thermal management - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A method and system for reducing thermal load by monitoring and controlling current flow in a portable computing device (“PCD”) are disclosed. The method includes monitoring a temperature of the PCD and determining if the temperature has reached a temperature threshold condition. This temperature threshold condition may be comprised within any one or more of a plurality of thermal policy states, in which each thermal policy state may dictate various thermal mitigation techniques. The thermal policy states may be associated with values that may indicate thermal loading of a PCD. If the temperature has reached the first threshold condition, then electrical current exiting a power supply device may be monitored. If it is determined that the electrical current has exceeded a current threshold condition, such as a maximum current, a hardware device corresponding to the electrical current may be selected for application of a thermal mitigation technique. ## Claims ### Claim 1 A method for reducing thermal load by monitoring and controlling current flow in a portable computing device, the method comprising: monitoring a temperature of the portable computing device; determining if the temperature has reached a temperature threshold condition; if the temperature has reached the temperature threshold condition, then monitoring electrical current exiting a plurality of power supply devices, each power supply device controlling power to one or more associated hardware devices; if the electrical current exiting one of the plurality of power supply devices has exceeded a current threshold condition, then selecting the hardware device corresponding to the electrical current for participating in a thermal mitigation technique. ### Claim 2 (depends on 1) The method of claim 1, further comprising applying a thermal mitigation technique in which current flow to the hardware device has been reduced. ### Claim 3 (depends on 1) The method of claim 1, further comprising applying a thermal mitigation technique in which the current flow to the hardware device is limited according to a time period. ### Claim 4 (depends on 1) The method of claim 1, further comprising applying a DVFS thermal mitigation technique that includes limiting a maximum frequency allowed for the hardware device. ### Claim 5 (depends on 4) The method of claim 4, wherein the DVFS thermal mitigation technique comprises one of limiting a maximum frequency for a plurality of cores in a multicore system and selecting a predetermined number of cores for scaling with a predetermine number of cores which will operate in an unconstrained manner. ### Claim 6 (depends on 1) The method of claim 1, further comprising applying a filtering technique to the monitored electrical current exiting a power supply device. ### Claim 7 (depends on 1) The method of claim 1, further comprising monitoring temperature of the portable computing device with at least one of an internal thermal sensor and an external thermal sensor. ### Claim 8 (depends on 7) The method of claim 7, further comprising determining if a change in temperature has been detected by at least one thermal sensor. ### Claim 9 (depends on 8) The method of claim 8, further comprising if the change in temperature has been detected by a thermal sensor, then increasing a frequency in which temperature readings are detected or in which electrical current exiting a power supply device is monitored. ### Claim 10 (depends on 1) The method of claim 1, wherein the temperature threshold condition comprises a plurality of thermal states and wherein each thermal state comprises a range of temperatures. ### Claim 11 A computer system for reducing thermal load by monitoring and controlling current flow in a portable computing device, the system comprising: a processor operable for: monitoring a temperature of the portable computing device; determining if the temperature has reached a temperature threshold condition; if the temperature has reached the temperature threshold condition, then monitoring electrical current exiting a plurality of power supply devices, each power supply device controlling power to one or more associated hardware devices; and selecting the hardware device corresponding to the electrical current for participating in a thermal mitigation technique if the electrical current has exceeded a current threshold condition. ### Claim 12 (depends on 11) The system of claim 11, wherein the processor is further operable for: applying a thermal mitigation technique in which current flow to the hardware device has been reduced. ### Claim 13 (depends on 11) The system of claim 11, wherein the processor is further operable for: applying a thermal mitigation technique in which the current flow to the hardware device is limited according to a time period. ### Claim 14 (depends on 11) The system of claim 11, wherein the processor operable for: applying a DVFS thermal mitigation technique that includes limiting a maximum frequency allowed for the hardware device. ### Claim 15 (depends on 14) The system of claim 14, wherein the DVFS thermal mitigation technique comprises one of limiting a maximum frequency for a plurality of cores in a multicore system and selecting a predetermined number of cores for scaling with a predetermine number of cores which will operate in an unconstrained manner. ### Claim 16 (depends on 11) The system of claim 11, wherein the processor operable for: applying a filtering technique to the monitored electrical current exiting a power supply device. ### Claim 17 (depends on 11) The system of claim 11, wherein the processor is further operable for: monitoring temperature of the portable computing device with at least one of an internal thermal sensor and an external thermal sensor. ### Claim 18 (depends on 17) The system of claim 17, wherein the processor is further operable for: determining if a change in temperature has been detected by at least one thermal sensor. ### Claim 19 (depends on 11) The system of claim 11, wherein the processor is further operable for: increasing a frequency in which temperature readings are detected or in which electrical current exiting a power supply device is monitored if the change in temperature has been detected by a thermal sensor. ### Claim 20 (depends on 11) The system of claim 11, wherein the temperature threshold condition comprises a plurality of thermal states and wherein each thermal state comprises a range of temperatures. ### Claim 21 A computer system for reducing thermal load by monitoring and controlling current flow in a portable computing device comprising: means for monitoring a temperature of the portable computing device; means for determining if the temperature has reached a temperature threshold condition; means for monitoring electrical current exiting a plurality of power supply devices if the temperature has reached the temperature threshold condition, each power supply device controlling power to one or more associated hardware devices; and means for selecting the hardware device corresponding to the electrical current for participating in a thermal mitigation technique if the electrical current has exceeded the current threshold condition. ### Claim 22 (depends on 21) The system of claim 21, further comprising: means for applying a thermal mitigation technique in which current flow to the hardware device has been reduced. ### Claim 23 (depends on 21) The system of claim 21, further comprising: means for applying a thermal mitigation technique in which the current flow to the hardware device is limited according to a time period. ### Claim 24 (depends on 21) The system of claim 21, further comprising means for applying a DVFS thermal mitigation technique that includes limiting a maximum frequency allowed for the hardware device. ### Claim 25 (depends on 24) The system of claim 24, wherein the DVFS thermal mitigation technique comprises one of limiting a maximum frequency for a plurality of cores in a multicore system and selecting a predetermined number of cores for scaling with a predetermine number of cores which will operate in an unconstrained manner. ### Claim 26 (depends on 21) The method of claim 21, further comprising: means for applying a filtering technique to the monitored electrical current exiting a power supply device. ### Claim 27 (depends on 21) The system of claim 21, further comprising: means for monitoring temperature of the portable computing device with at least one of an internal thermal sensor and an external thermal sensor. ### Claim 28 (depends on 21) The system of claim 21, further comprising: means for determining if a change in temperature has been detected by at least one thermal sensor. ### Claim 29 (depends on 28) The system of claim 28, further comprising: means for increasing a frequency in which temperature readings are detected or in which electrical current exiting a power supply device is monitored if the change in temperature has been detected by a thermal sensor. ### Claim 30 (depends on 21) The system of claim 21, wherein the temperature threshold condition comprises a plurality of thermal states and wherein each thermal state comprises a range of temperatures. ### Claim 31 A computer program product comprising a non-transitory computer usable medium having a computer readable program code embodied therein, said computer readable program code adapted to be executed to implement a method for reducing thermal load by monitoring and controlling current flow in a portable computing device comprising, said method comprising: monitoring a temperature of the portable computing device; determining if the temperature has reached a temperature threshold condition; if the temperature has reached the temperature threshold condition, then monitoring electrical current exiting a plurality of power supply devices, each power supply device controlling power to one or more associated hardware devices; and if the electrical current has exceeded the current threshold condition, then selecting the hardware device corresponding to the electrical current for participating in a thermal mitigation technique. ### Claim 32 (depends on 31) The computer program product of claim 31, wherein the program code implementing the method further comprises: applying a thermal mitigation technique in which current flow to the hardware device has been reduced. ### Claim 33 (depends on 31) The computer program product of claim 31, wherein the program code implementing the method further comprises: applying a thermal mitigation technique in which the current flow to the hardware device is limited according to a time period. ### Claim 34 (depends on 31) The computer program product of claim 31, wherein the program code implementing the method further comprises: applying a DVFS thermal mitigation technique that includes limiting a maximum frequency allowed for the hardware device. ### Claim 35 (depends on 34) The computer program product of claim 34, wherein the DVFS thermal mitigation technique comprises one of limiting a maximum frequency for a plurality of cores in a multicore system and selecting a predetermined number of cores for scaling with a predetermine number of cores which will operate in an unconstrained manner. ### Claim 36 (depends on 31) The computer program product of claim 31, wherein the program code implementing the method further comprises: applying a filtering technique to the monitored electrical current exiting a power supply device. ### Claim 37 (depends on 31) The computer program product of claim 31, wherein the program code implementing the method further comprises: monitoring temperature of the portable computing device with at least one of an internal thermal sensor and an external thermal sensor. ### Claim 38 (depends on 37) The computer program product of claim 37, wherein the program code implementing the method further comprises: determining if a change in temperature has been detected by at least one thermal sensor. ### Claim 39 (depends on 31) The computer program product of claim 31, wherein the program code implementing the method further comprises: increasing a frequency in which temperature readings are detected or in which electrical current exiting a power supply device is monitored if the change in temperature has been detected by a thermal sensor. ### Claim 40 (depends on 31) The computer program product of claim 31, wherein the temperature threshold condition comprises a plurality of thermal states and wherein each thermal state comprises a range of temperatures.