# US 2021/0333334 A1 · Power supply peak current measurement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0333334 A1 - Document ID: US20210333334A1 - Status: Published application - Kind: A1 - Application number: 17/205,042 - Filed: 2021-03-18 - Published: 2021-10-28 - Earliest claimed: 2020-04-22 - Assignees: NXP USA, Inc. - Applicants: NXP USA, Inc. - Inventors: Michael Andreas Staudenmaier; Vincent Aubineau; Michael Rohleder - Web page: https://patentgrep.com/patent/US20210333334A1 ## CPC - G01R 19/04: Measuring peak values {or amplitude or envelope} of AC or of pulses - G01R 31/58: Testing of lines, cables or conductors (testing of electric windings G01R31/72) - G01R 19/16571: {comparing AC or DC current with one threshold, e.g. load current, over-current, surge current or fault current (G01R19/16514, G01R19/16519, G01R19/16528, G01R19/16533, G01R19/1659 take precedence; measuring currents by using elements sensitive to the magnetic field generated G01R15/14; measuring earth resistance G01R27/18; testing for leakage or short circuits in electrical apparatus G01R31/52)} - G01R 19/2506: {Arrangements for conditioning or analysing measured signals, e.g. for indicating peak values (G01R19/003 takes precedence); Details concerning sampling, digitizing or waveform capturing (displaying waveforms G01R13/00; analog sampling G01R19/0053)} - G01R 31/31719: {Security aspects, e.g. preventing unauthorised access during test} - G06F 1/28: Supervision thereof, e.g. detecting power-supply failure by out of limits supervision - H04L 63/0428: {wherein the data content is protected, e.g. by encrypting or encapsulating the payload} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A peak current detector is integrated into a power supply, such as a power management integrated circuit, to detect glitch attacks imposed on the power rails inside the power supply. Integrated circuitry being supplied by the power supply periodically checks the state of the power supply via a secure communication channel to obtain the detected peak current values, which allow the integrated circuitry to detect those attacks and react accordingly to any possible threats. ## Claims ### Claim 1 A power supply comprising: circuitry configured to output a voltage signal on a power output line; a peak detector configured to monitor current associated with the voltage signal for an occurrence of a glitch; and circuitry configured to output a signal from the power supply representing the occurrence of the glitch. ### Claim 2 (depends on 1) The power supply of claim 1, wherein the circuitry configured to output the signal comprises a communication interface configured to encrypt the signal. ### Claim 3 (depends on 1) The power supply of claim 1, wherein the peak detector comprises a peak current detector circuit that includes a current shunt coupled to the power output line. ### Claim 4 (depends on 3) The power supply of claim 3, wherein the peak detector comprises a comparator configured to compare an output of the peak current detector circuit to a predetermined threshold value. ### Claim 5 (depends on 4) The power supply of claim 4, wherein the signal represents an occurrence of the output of the peak current detector circuit exceeding the threshold value. ### Claim 6 (depends on 4) The power supply of claim 4, wherein the peak detector comprises an analog-to-digital converter configured to produce a digital signal representative of the output of the peak current detector circuit, wherein the comparator is configured to compare an output of the analog-to-digital converter to the predetermined threshold value. ### Claim 7 (depends on 4) The power supply of claim 4, wherein the peak detector comprises: a digital-to-analog converter configured to convert the predetermined threshold value to an analog value; and an analog comparator configured to compare the analog value to the output of the peak current detector circuit. ### Claim 8 (depends on 1) The power supply of claim 1, wherein the power supply is implemented as a power management integrated circuit. ### Claim 9 A method for detecting a glitch occurring on a power output line supplying a voltage signal from a power management integrated circuit (“PMIC”), the method comprising: monitoring of current associated with the voltage signal by a peak detector implemented within the PMIC; encrypting an output of the peak detector; and transmitting the encrypted output from the PMIC. ### Claim 10 (depends on 9) The method of claim 9, further comprising: receiving by an integrated circuit the encrypted output from the PMIC; and entering into a tampered state of operation by the integrated circuit when the encrypted output transmitted from the PMIC indicates that the current associated with the voltage signal has a level that exceeds a predetermined threshold value, wherein the predetermined threshold value represents a maximum current expected to be drawn by the integrated circuit from the PMIC. ### Claim 11 (depends on 10) The method of claim 10, further comprising: transmitting the predetermined threshold value from the integrated circuit to the PMIC; and comparing the output from the peak detector to the predetermined threshold value, wherein the encrypted output transmitted from the PMIC to the integrated circuit represents a comparison of the output from the peak detector to the predetermined threshold value. ### Claim 12 (depends on 10) The method of claim 10, further comprising: sending, by the integrated circuit, a request to the PMIC for the output from the peak detector, wherein the transmitting of the encrypted output from the PMIC is performed in response to the request. ### Claim 13 (depends on 12) The method of claim 12, further comprising encrypting the request by the integrated circuit before sending to the PMIC. ### Claim 14 A power management integrated circuit (“PMIC”) comprising: a voltage regulator circuit configured to output a voltage signal onto a power output line; a peak detector configured to measure a current level on the power output line; and a communication interface configured to encrypt an output signal from the peak detector and to transmit the encrypted output signal from the PMIC. ### Claim 15 (depends on 14) The PMIC as recited in claim 14, wherein the communication interface is configured to receive a communication signal representing a threshold value from a source external to the PMIC. ### Claim 16 (depends on 15) The PMIC as recited in claim 15, wherein the communication signal is encrypted, and wherein the communication interface is configured to decrypt the communication signal to produce the threshold value. ### Claim 17 (depends on 15) The PMIC as recited in claim 15, wherein the peak detector comprises: a digital-to-analog converter configured to convert the threshold value to an analog value; and an analog comparator configured to compare the analog value to the output signal from the peak detector. ### Claim 18 (depends on 15) The PMIC as recited in claim 15, wherein the peak detector comprises: an analog-to-digital convertor configured to convert the output signal from the peak detector to a digital value; and a digital comparator configured to compare the digital value to the threshold value. ### Claim 19 (depends on 15) The PMIC as recited in claim 15, wherein the PMIC is configured to shut off output of the voltage signal onto the power output line in response to the current level exceeding the threshold value. ### Claim 20 (depends on 14) The PMIC as recited in claim 14, wherein the peak detector is configured to detect a glitch attack occurring on the power output line.