# US 10,771,052 B2 · Gate driver with VGTH and VCESAT measurement capability for the state of health monitor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,771,052 B2 - Document ID: US10771052B2 - Status: Granted - Kind: B2 - Application number: 16/371,331 - Filed: 2019-04-01 - Published: 2019-07-25 - Granted: 2020-09-08 - Earliest claimed: 2016-10-07 - Assignees: Texas Instruments Incorporated - Applicants: Texas Instruments Incorporated - Inventors: Xiong Li; Anant Kamath - Web page: https://patentgrep.com/patent/US10771052B2 ## CPC - H03K 17/567: Circuits characterised by the use of more than one type of semiconductor device, e.g. BIMOS, composite devices such as IGBT - G01R 31/2608: {for testing bipolar transistors} - G01R 31/2621: {for testing field effect transistors, i.e. FET's} - G01R 31/2817: {Environmental-, stress-, or burn-in tests (of IC's G01R31/2855; of individual semiconductors G01R31/2642; of other circuits G01R31/2849)} - G01R 31/2837: {Characterising or performance testing, e.g. of frequency response (transient response G01R27/28)} - G01R 31/2849: {Environmental or reliability testing, e.g. burn-in or validation tests (of individual semiconductors G01R31/2642; of printed circuits boards G01R31/2817; of IC's G01R31/2855)} - H03K 17/18: Modifications for indicating state of switch - G01R 31/42: AC power supplies - 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 An isolated insulated gate bipolar transistor (IGBT) gate driver is provided which integrates circuits, in-module, to support the measurements of threshold voltage, and collector-emitter saturation voltage of IGBTs. The measured gate threshold and collector-emitter saturation voltage can be used as precursors for state of health predictions for IGBTs. During the measurements, IGBTs are biased under specific conditions chosen to quickly elicit collector-emitter saturation and gate threshold information. Integrated analog-to-digital converter (ADC) circuits are used to convert measured analog signals to a digital format. The digitalized signals are transferred to a micro controller unit (MCU) for further processing through serial peripheral interface (SPI) circuits. ## Claims ### Claim 1 An apparatus comprising: a current source having a current output terminal; a pass transistor having a first terminal coupled to the current output terminal, a gate terminal, and a second terminal; a multiplexer having a first input coupled to the first terminal of the pass transistor, a second input coupled to the second terminal of the pass transistor, and a selected output; and an analog-to-digital converter (ADC) having an analog input coupled to the selected output, and a digital output. ### Claim 2 (depends on 1) The apparatus of claim 1, further comprising: a power transistor having a first terminal, a gate terminal coupled to the second input of the multiplexer, and a second terminal; and a diode having an anode coupled to the first terminal of the pass transistor, and a cathode coupled to the first terminal of the power transistor. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the power transistor includes an insulated-gate bipolar transistor having a collector terminal arranged as the first terminal, and an emitter terminal arranged as the second terminal. ### Claim 4 (depends on 3) The apparatus of claim 3, further comprising: a control circuit configured to: activate a pull-up circuit for charging the gate terminal of the power transistor; and receive a digitized collector-emitter voltage of the power transistor from the ADC after the power transistor is in saturation. ### Claim 5 (depends on 2) The apparatus of claim 2, wherein the diode includes a desaturation diode configured to block a desaturation voltage of the first terminal of the power transistor from the first terminal of the pass transistor. ### Claim 6 (depends on 2) The apparatus of claim 2, wherein the multiplexer includes a selection input coupled to the second terminal of the power transistor, the multiplexer configured to select either one of the first input or the second input as the selected output based on the selection input. ### Claim 7 (depends on 2) The apparatus of claim 2, further comprising: a control circuit coupled to the gate terminal of the pass transistor and the digital output of the ADC, the control circuit configured to: activate the pass transistor for charging the gate terminal of the power transistor; and receive a digitized gate voltage of the power transistor from the ADC after the power transistor is in saturation. ### Claim 8 A power supply system comprising: a power transistor having a first terminal, a gate terminal, and a second terminal; a current source having a current output terminal; a pass transistor having a first terminal coupled to the current output terminal, a gate terminal, and a second terminal coupled to the gate terminal of the power transistor; a multiplexer having a first input coupled to the first terminal of the pass transistor, a second input coupled to the second terminal of the pass transistor, and a selected output; and an analog-to-digital converter (ADC) having an analog input coupled to the selected output, and a digital output. ### Claim 9 (depends on 8) The power supply system of claim 8, further comprising: a diode having an anode coupled to the first terminal of the pass transistor, and a cathode coupled to the first terminal of the power transistor. ### Claim 10 (depends on 9) The power supply system of claim 9, wherein the diode includes a desaturation diode configured to block a desaturation voltage of the first terminal of the power transistor from the first terminal of the pass transistor. ### Claim 11 (depends on 8) The power supply system of claim 8, wherein the power transistor includes an insulated-gate bipolar transistor having a collector terminal arranged as the first terminal, and an emitter terminal arranged as the second terminal. ### Claim 12 (depends on 11) The power supply system of claim 11, further comprising: a control circuit configured to: activate a pull-up circuit for charging the gate terminal of the power transistor; and receive a digitized collector-emitter voltage of the power transistor from the ADC after the power transistor is in saturation. ### Claim 13 (depends on 8) The power supply system of claim 8, wherein the multiplexer includes a selection input coupled to the second terminal of the power transistor, the multiplexer configured to select either one of the first input or the second input as the selected output based on the selection input. ### Claim 14 (depends on 8) The power supply system of claim 8, further comprising: a control circuit coupled to the gate terminal of the pass transistor and the digital output of the ADC, the control circuit configured to: activate the pass transistor for charging the gate terminal of the power transistor; and receive a digital gate voltage of the power transistor after the power transistor is in saturation.