# US 2019/0173374 A1 · Converter Apparatus and Method with Auxiliary Transistor for Protecting Components at Startup > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0173374 A1 - Document ID: US20190173374A1 - Status: Published application - Kind: A1 - Application number: 16/266,983 - Filed: 2019-02-04 - Published: 2019-06-06 - Earliest claimed: 2017-04-26 - Assignees: Futurewei Technologies, Inc. - Applicants: Futurewei Technologies, Inc. - Inventors: Dianbo Fu; Fei Ye; Lei Shi - Web page: https://patentgrep.com/patent/US20190173374A1 ## CPC - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 7/4837: {Flying capacitor converters} - H02H 11/002: {in case of inverted polarity or connection; with switching for obtaining correct connection} - H02M 1/36: Means for starting or stopping converters - H02M 3/07: using capacitors charged and discharged alternately by semiconductor devices with control electrode {, e.g. charge pumps} - H02M 3/156: with automatic control of output voltage or current, e.g. switching regulators - H02M 3/158: including plural semiconductor devices as final control devices for a single load - H02M 7/44: by static converters - 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) - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) ## Abstract In certain embodiments, an apparatus includes an inductor having first and second terminals. The first terminal is configured to be coupled to a power source. The apparatus includes a pair of serially-coupled transistors coupled to the second terminal of the inductor. A transistor intermediate node is positioned between the pair of serially-coupled transistors. The apparatus includes a pair of serially-coupled diodes coupled to the second terminal of the inductor. A diode intermediate node is positioned between the pair of serially-coupled diodes. The apparatus includes a first capacitor coupled in parallel with the serially-coupled transistors and the serially-coupled diodes. The apparatus includes a sub-circuit having a second capacitor serially-coupled with an auxiliary transistor. The sub-circuit is coupled between the transistor intermediate node and the diode intermediate node and is in parallel with a transistor of the pair of serially coupled transistors and with a diode of the pair of serially-coupled diodes. ## Claims ### Claim 1 An apparatus, comprising: an inductor including a first terminal and a second terminal, the first terminal configured to be coupled to a power source; a pair of serially-coupled transistors coupled to the second terminal of the inductor, a transistor intermediate node being positioned between the pair of serially-coupled transistors; a pair of serially-coupled diodes coupled to the second terminal of the inductor, a diode intermediate node being positioned between the pair of serially-coupled diodes; a first capacitor coupled in parallel with the serially-coupled transistors and the serially-coupled diodes; and a sub-circuit including a second capacitor serially-coupled with an auxiliary transistor, the sub-circuit coupled between the transistor intermediate node and the diode intermediate node and being in parallel with a transistor of the pair of serially coupled transistors and being in parallel with a diode of the pair of serially-coupled diodes. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the auxiliary transistor is configured to be activated at start up, in an event that the power source is improperly coupled, for reducing a voltage stress on at least a portion of the apparatus. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the auxiliary transistor reduces the voltage stress on at least one of the pair of serially-coupled transistors. ### Claim 4 (depends on 2) The apparatus of claim 2, wherein the auxiliary transistor reduces the voltage stress on at least one of the pair of serially-coupled diodes. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the first capacitor is configured for storing a voltage amount that is less than or equal to half of an output voltage of the apparatus. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the first capacitor is configured for reducing a voltage stress on at least a portion of the apparatus. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the auxiliary transistor is of a same type as the pair of serially-coupled transistors. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the auxiliary transistor is of a different type as compared to the pair of serially-coupled transistors. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the sub-circuit further includes a third capacitor coupled in parallel with the auxiliary transistor. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the sub-circuit further includes a resistor coupled in parallel with the auxiliary transistor. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein the auxiliary transistor is an insulated-gate bipolar transistor (IGBT). ### Claim 12 (depends on 1) The apparatus of claim 1, wherein the auxiliary transistor is a metal oxide semiconductor field effect transistor (MOSFET). ### Claim 13 A method, comprising: applying an electric current to a converter circuit, the converter circuit including: an inductor including a first terminal and a second terminal, the first terminal configured to be coupled to a power source; a pair of serially-coupled transistors coupled to the second terminal of the inductor, a transistor intermediate node being positioned between the pair of serially-coupled transistors; a pair of serially-coupled diodes coupled to the second terminal of the inductor, a diode intermediate node being positioned between the pair of serially-coupled diodes; a first capacitor coupled in parallel with the serially-coupled transistors and the serially-coupled diodes; and a sub-circuit including a second capacitor serially-coupled with an auxiliary transistor, the sub-circuit coupled between the transistor intermediate node and the diode intermediate node and being in parallel with a transistor of the pair of serially coupled transistors and being in parallel with a diode of the pair of serially-coupled diodes; and activating, in response to the application of the electric current, the auxiliary transistor to reduce a voltage stress on at least a portion of the converter circuit. ### Claim 14 (depends on 13) The method of claim 13, wherein the auxiliary transistor reduces the voltage stress on the at least portion of the converter circuit in an event that the power source is improperly coupled. ### Claim 15 (depends on 14) The method of claim 14, wherein the auxiliary transistor reduces the voltage stress on at least one of the pair of serially-coupled transistors. ### Claim 16 (depends on 14) The method of claim 14, wherein the auxiliary transistor reduces the voltage stress on at least one of the pair of serially-coupled diodes. ### Claim 17 (depends on 13) The method of claim 13, and further comprising storing, utilizing the first capacitor, a voltage amount that is less than or equal to half of an output voltage of the converter circuit. ### Claim 18 (depends on 13) The method of claim 13, and further comprising reducing, utilizing the first capacitor, the voltage stress on at least a part of the converter circuit. ### Claim 19 (depends on 13) The method of claim 13, wherein the auxiliary transistor is of a same type as the pair of serially-coupled transistors. ### Claim 20 (depends on 13) The method of claim 13, wherein the sub-circuit further includes a third capacitor coupled in parallel with the auxiliary transistor. ### Claim 21 (depends on 13) The method of claim 13, wherein the sub-circuit further includes a resistor coupled in parallel with the auxiliary transistor. ### Claim 22 An apparatus, comprising: an inductor means for storing electrical energy in a magnetic field when an electric current is applied; a transistor means in communication with the inductor means for switching on and off during runtime operation; a diode means in communication with the inductor means for allowing current to pass in a single direction; a protection means in communication with the diode means and the transistor means for offloading, in response to an input voltage being misapplied, at least a portion of voltage stress from the diode means and the transistor means.