# US 10,768,229 B2 · Glitch detection of a DC voltage > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,768,229 B2 - Document ID: US10768229B2 - Status: Granted - Kind: B2 - Application number: 16/059,793 - Filed: 2018-08-09 - Published: 2019-03-21 - Granted: 2020-09-08 - Earliest claimed: 2017-09-21 - Assignees: STMicroelectronics (Rousset) SAS - Applicants: STMicroelectronics (Rousset) SAS - Inventors: Nicolas Borrel; Jimmy Fort - Web page: https://patentgrep.com/patent/US10768229B2 ## CPC - G01R 31/31721: {Power aspects, e.g. power supplies for test circuits, power saving during test (for scan test G01R31/318575)} - G01R 19/165: Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values - G01R 19/16552: {in I.C. power supplies} - G01R 31/40: Testing power supplies (testing photovoltaic devices H02S50/10) - G06F 1/28: Supervision thereof, e.g. detecting power-supply failure by out of limits supervision - H02M 1/0009: {Devices or circuits for detecting current in a converter} - 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) - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) ## Abstract A circuit for detecting a glitch in power supply includes a detection circuit to detect the glitch in a DC supply voltage of the power supply when a magnitude in the glitch in a DC supply voltage of the power supply exceeds a detection threshold, wherein the detection threshold is a function of the DC supply voltage, and wherein the detection circuit comprises a low pass filter, a control circuit coupled to the low pass filter, and a current mirror circuit coupled to the control circuit having an output for providing a logic signal indicative of a detected glitch. ## Claims ### Claim 1 A circuit for detecting a glitch in power supply, the circuit comprising: a detection circuit configured to detect the glitch in a DC supply voltage of the power supply when a magnitude in the glitch in a DC supply voltage of the power supply exceeds a detection threshold, wherein the detection threshold is a function of the DC supply voltage, wherein the detection circuit comprises a control circuit configured for providing a current proportional to a filtered voltage obtained by low-pass filtering of the DC supply voltage; and a current mirror circuit coupled to and distinct from the control circuit, the current mirror circuit having an output configured for providing a logic signal indicative of a detected glitch. ### Claim 2 (depends on 1) The circuit of claim 1, wherein the detection threshold varies proportionally to the filtered voltage obtained by low-pass filtering of the DC supply voltage. ### Claim 3 (depends on 2) The circuit of claim 2, wherein a first current varying linearly proportionally to the filtered voltage obtained by filtering conditions the detection threshold. ### Claim 4 (depends on 3) The circuit of claim 3, further comprising a low-pass filter configured to supply the filtered voltage coupled between a first terminal and a second terminal of the power supply providing the DC supply voltage. ### Claim 5 A circuit for detecting a glitch in power supply, the circuit comprising: a first low-pass filter configured to supply a filtered voltage coupled between a first terminal and a second terminal of the power supply providing a DC supply voltage; a detection circuit coupled to the first low-pass filter and configured to detect the glitch in the DC supply voltage when an amplitude in the glitch in a DC supply voltage of the power supply exceeds a detection threshold proportionally varying with the filtered voltage, wherein the detection circuit comprises: a first branch comprising a first transistor and a first current source; and a second branch comprising a first resistor, a second transistor mirror-assembled with the first transistor, and a second current source supplying a first current varying proportionally to the filtered voltage. ### Claim 6 (depends on 5) The circuit of claim 5, further comprising: a third transistor, the second current source comprising a fourth transistor mirror-assembled with the third transistor; and a control circuit configured to supply the third transistor with a second current varying proportionally to the filtered voltage. ### Claim 7 (depends on 6) The circuit of claim 6, wherein the first current source comprises a fifth transistor mirror-assembled with the third transistor. ### Claim 8 (depends on 6) The circuit of claim 6, wherein the control circuit comprises a second resistor and is further configured to impose the filtered voltage across the second resistor, the second current varying proportionally to a third current running through the second resistor. ### Claim 9 (depends on 8) The circuit of claim 8, wherein the control circuit comprises: a sixth transistor series-connected with the third transistor between the first terminal and the second terminal; and a seventh transistor in series with the second resistor between the first terminal and the second terminal, a control terminal of the seventh transistor being coupled to a control terminal of the sixth transistor. ### Claim 10 (depends on 9) The circuit of claim 9, wherein the control circuit comprises an operational amplifier having a first input connected to an output of the first low-pass filter, having a second input connected to the junction point of the seventh transistor and of the second resistor, and having an output connected to the control terminals of the sixth and seventh transistors. ### Claim 11 (depends on 10) The circuit of claim 10, wherein the first input of the amplifier is the inverting input and the second input of the amplifier is the non-inverting input. ### Claim 12 (depends on 5) The circuit of claim 5, further comprising a second low-pass filter connected to a control terminal of each of the first and second transistors. ### Claim 13 (depends on 5) The circuit of claim 5, further comprising a second low-pass filter coupling the first terminal to the first resistor. ### Claim 14 (depends on 13) The circuit of claim 13, wherein the second low-pass filter comprises an additional capacitor in parallel with the first resistor and a second resistor in series with the additional capacitor and the first resistor. ### Claim 15 (depends on 13) The circuit of claim 13, wherein the second low-pass filter determines a minimum frequency of the glitch that is detectable by the circuit. ### Claim 16 (depends on 13) The circuit of claim 13, wherein the second transistor is configured to change from a first conductive state to a second conductive state for a negative glitch when a frequency of the glitch is greater than a cut-off frequency of the second low-pass filter and the amplitude of the glitch is greater than the detection threshold. ### Claim 17 (depends on 5) The circuit of claim 5, wherein the second transistor is configured to change from a first conductive state to a second conductive state for a positive glitch when a frequency of the glitch is greater than a cut-off frequency of the first low-pass filter and the amplitude of the glitch is greater than the detection threshold. ### Claim 18 (depends on 5) The circuit of claim 5, further comprising an additional resistor coupled between a gate of the first transistor and a gate of the second transistor. ### Claim 19 (depends on 5) The circuit of claim 5, further comprising an additional capacitor between a gate and a source of the first transistor. ### Claim 20 (depends on 5) The circuit of claim 5, wherein the first transistor and the second transistor are MOS transistors or bipolar transistors. ### Claim 21 (depends on 5) The circuit of claim 5, wherein the circuit is configured to detect the glitch across an entire power supply range comprising 1.62V to 5.5V. ### Claim 22 A method of detecting a glitch in power supply, the method comprising: detecting the glitch in a DC supply voltage across an entire power supply range using a detection circuit by setting a detection threshold that depends on the DC supply voltage; and identifying a glitch when a magnitude in the glitch in the DC supply voltage of the power supply exceeds the detection threshold; and at a first low-pass filter, filtering the DC supply voltage to generate a filtered voltage, wherein the detection threshold proportionally varies with the filtered voltage; having a detection circuit coupled to the first low-pass filter, the detection circuit comprising a control circuit and a current mirror circuit coupled to and distinct from the control circuit including: a first branch comprising a first transistor and a first current source; and a second branch comprising a first resistor, a second transistor mirror-assembled with the first transistor, and a second current source supplying a first current varying proportionally to the filtered voltage. ### Claim 23 (depends on 22) The method of claim 22, further comprising: having a second low-pass filter coupled to the first resistor; and in response to a negative glitch, changing a state of the second transistor from a first conductive state to a second conductive state when a frequency of the glitch is greater than a cut-off frequency of the second low-pass filter and the amplitude of the glitch is greater than the detection threshold. ### Claim 24 (depends on 22) The method of claim 22, in response to a positive glitch, changing a state of the second transistor from a first conductive state to a second conductive state when a frequency of the glitch is greater than a cut-off frequency of the first low-pass filter and the amplitude of the glitch is greater than the detection threshold.