# US 2021/0344337 A1 · Method for protecting a transistor from overload and electronic circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0344337 A1 - Document ID: US20210344337A1 - Status: Published application - Kind: A1 - Application number: 17/223,243 - Filed: 2021-04-06 - Published: 2021-11-04 - Earliest claimed: 2020-04-30 - Assignees: Infineon Technologies AG - Applicants: Infineon Technologies AG - Inventors: Markus Bader - Web page: https://patentgrep.com/patent/US20210344337A1 ## CPC - H03K 17/08142: {in field-effect transistor switches} - H03K 17/0822: {in field-effect transistor switches} - G01R 1/203: {Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts (resistors in general H01C; microwave or radiowave terminations H01P1/26; coupling devices H01R)} - G01R 19/16538: {in AC or DC supplies (G01R19/16519 and G01R19/16528 take precedence)} - H03K 2217/0027: Measuring means of, e.g. currents through or voltages across the switch - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A method is described. The method comprises determining a first measurement signal (CS1) which depends on a first load current (I1) through a first transistor (Q1) which is connected in series to a load (Z); determining a second measurement signal (CS2) which depends on a second load current (I2) through a second transistor (Q2) which is connected in series to the load (Z); and comparing the first measurement signal (CS1) and the second measurement signal (CS2), in order to detect the presence of an error. ## Claims ### Claim 1 A method comprising determining a first measurement signal which depends on a first load current through a first transistor which is connected in series to a load; determining a second measurement signal which depends on a second load current through a second transistor which is connected in series to the load; and comparing the first measurement signal and the second measurement signal, in order to detect the presence of an error. ### Claim 2 (depends on 1) The method according to claim 1, wherein the presence of an error is detected if one of the first and the second measurement signal deviates from the other of the first and the second measurement signal by more than a predetermined value. ### Claim 3 (depends on 1) The method according to claim 1, wherein determining the first measurement signal comprises detecting a load path voltage of the first transistor. ### Claim 4 (depends on 3) The method according to claim 3, wherein generating the first current measurement signal includes detecting the load path voltage and amplifying the load path voltage using an amplifier. ### Claim 5 (depends on 1) The method according to claim 1, wherein determining the second measurement signal comprises measuring a load path voltage of the second transistor. ### Claim 6 (depends on 1) The method according to claim 1, wherein determining the second measurement signal comprises generating a measurement current which depends on the second load current. ### Claim 7 (depends on 6) The method according to claim 6, wherein the second transistor has a load current output and a measurement current output and wherein the measurement current is provided by a current detection circuit which is coupled to the load current output and the measurement current output. ### Claim 8 (depends on 6) The method according to claim 6, wherein determining the second measurement signal includes conducting the measurement current through a measuring resistor, wherein the second measurement signal comprises a voltage across the measuring resistor. ### Claim 9 (depends on 1) The method according to claim 1, wherein the first transistor comprises a low-side of an H-bridge, and wherein the second transistor comprises a high-side transistor of the H-bridge. ### Claim 10 (depends on 1) The method according to claim 1, the method further comprising: switching off at least one of the first transistor and the second transistor when an error is detected. ### Claim 11 (depends on 1) The method according to claim 1, the method further comprising: controlling the second transistor in accordance with a fuse characteristic curve which depends on the second load current. ### Claim 12 (depends on 1) The method according to claim 1, the method further comprising: comparing the first measurement signal with a fixed predetermined threshold value; and switching off the first transistor if the first measurement signal reaches or exceeds the fixedly predetermined threshold value. ### Claim 13 An electronic circuit comprising: a first electronic switch configured to be connected in series to a load; a second electronic switch configured to be connected in series to the load; an error detection circuit configured to determine a first measurement signal which depends on a first load current through the first transistor, to determine a second measurement signal which depends on a second load current through the second transistor, and to compare the first measurement signal and the second measurement signal, in order to detect the presence of an error. ### Claim 14 (depends on 13) The electronic circuit according to claim 13, wherein the error detection circuit is configured to detect an error if one of the first measurement signal or the second measurement signal deviates from the other of the first measurement signal and the second measurement signal by more than a predetermined value. ### Claim 15 (depends on 13) The electronic circuit according to claim 13, wherein the error detection circuit (3) is configured to detect a load path voltage of the first electronic switch for determining the first measurement signal. ### Claim 16 (depends on 15) The electronic circuit according to claim 15, wherein the second transistor includes a load current output and a measurement current output and wherein the error detection circuit includes a controller which is coupled to the load current output and the measurement current output and which is configured to generate a measurement current which depends on the second load current. ### Claim 17 (depends on 16) The electronic circuit according to claim 16, wherein the error detection circuit further includes a measuring resistor which is connected in series to the controller, wherein the second measurement signal comprises a voltage across the measuring resistor. ### Claim 18 (depends on 13) The electronic circuit according to claim 13, wherein the error detection circuit includes an amplifier which is coupled to the load path of the first transistor and which provides the first current measurement signal ### Claim 19 (depends on 13) The electronic circuit according to claim 13, wherein the first switch comprises a low-side switch of an H-bridge and wherein the second switch comprises a high-side switch of the H-bridge. ### Claim 20 (depends on 13) The electronic circuit according to claim 13, the electronic circuit further comprising: a control circuit which is configured to switch off at least one of the first electronic switch and the second electronic switch if the presence of an error is detected by the error detection circuit. ### Claim 21 (depends on 13) The electronic circuit according to claim 13, wherein the second electronic switch and the error detection circuit are part of a common integrated circuit, and wherein the first electronic switch is arranged outside the integrated circuit.