# US 11,114,941 B2 · Reduced voltage ratings for power transistors in a buck converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,114,941 B2 - Document ID: US11114941B2 - Status: Granted - Kind: B2 - Application number: 16/732,201 - Filed: 2019-12-31 - Published: 2021-07-01 - Granted: 2021-09-07 - Earliest claimed: 2019-12-31 - Assignees: Texas Instruments Incorporated - Applicants: Texas Instruments Incorporated - Inventors: Riazdeen Buhari - Web page: https://patentgrep.com/patent/US11114941B2 ## CPC - H02M 3/158: including plural semiconductor devices as final control devices for a single load - B60R 16/033: characterised by the use of electrical cells or batteries (for propulsion puposes B60K1/04; supplying batteries to, or removing batteries from, vehicles B60S5/06; testing of charge state G01R31/36) - H02M 1/0048: {Circuits or arrangements for reducing losses (using snubbers H02M1/34)} - H02M 1/08: Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters - H02M 1/0045: {Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode} - Y02B 70/10: Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes - 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) - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A device includes a buck converter coupled to an input node and an output node, and a linear voltage regulator coupled to the input node and to the output node. ## Claims ### Claim 1 A device, comprising: a buck converter configured to generate an output voltage based on an input voltage; a port controller coupled to the buck converter and configured to couple to a pass transistor, the port controller configured to: receive a first signal indicating that the input voltage is above a first threshold voltage; generate a control signal for turning off the pass transistor in response to receiving the first signal; receive a second signal indicating that a gate voltage of the pass transistor is below a second threshold voltage; and turn off the buck converter in response to receiving the second signal; and a linear voltage regulator configured to regulate the output voltage while the buck converter is turned off. ### Claim 2 (depends on 1) The device of claim 1, further comprising a comparator configured to generate the first signal that the input voltage is above a first threshold voltage. ### Claim 3 (depends on 1) The device of claim 1, further comprising: a first pass transistor coupled to the buck converter and the port controller; and a second pass transistor coupled to the buck converter and to the port controller, wherein the first and second pass transistors are configured to selectively couple first and second loads, respectively, to the buck converter. ### Claim 4 (depends on 3) The device of claim 3, wherein the port controller is further configured to: receive a third signal indicating that a gate voltage of each of the first and second pass transistors is below the second threshold voltage; and turn off the buck converter in response to receiving the third signal. ### Claim 5 (depends on 1) The device of claim 1, wherein the port controller is further configured to: receive a third signal indicating that the input voltage is below the first threshold voltage; and turn on the pass transistor and the buck converter in response to receiving the third signal. ### Claim 6 A method for operating a buck converter, comprising: receiving a first signal indicating that an input voltage to the buck converter is above a first threshold voltage; in response to receiving the first signal, generating a control signal for turning off a pass transistor coupled to an output of the buck converter; receiving a second signal indicating that a gate voltage of the pass transistor is below a second threshold voltage; in response to receiving the second signal, turning off the buck converter; and regulating a voltage of the output of the buck converter after turning off the buck converter. ### Claim 7 (depends on 6) The method of claim 6, further comprising generating, by a comparator, the first signal that the input voltage is above a first threshold voltage. ### Claim 8 (depends on 6) The method of claim 6, further comprising: selectively coupling a first load to the buck converter by a first pass transistor; and selectively coupling a second load to the buck converter by a second pass transistor. ### Claim 9 (depends on 8) The method of claim 8, further comprising: receiving a third signal indicating that a gate voltage of each of the first and second pass transistors is below the second threshold voltage; and in response to receiving the third signal, turning off the buck converter. ### Claim 10 (depends on 6) The method of claim 6, further comprising: receiving a third signal indicating that the input voltage is below the first threshold voltage; and in response to receiving the third signal, turning on the pass transistor and the buck converter. ### Claim 11 A device, comprising: a buck converter adapted to be coupled to an automotive battery to receive an input voltage, the buck converter configured to generate an output voltage based on the input voltage; a first comparator having an input coupled to the automotive battery and configured to assert a first output signal in response to the input voltage being above a first threshold voltage; a port controller coupled to the buck converter and configured to couple to a pass transistor, the port controller comprising: a second comparator having an input coupled to a control terminal of the pass transistor and configured to assert a second output signal in response to a voltage of the control terminal being below a second threshold voltage; and a NAND gate having inputs configured to receive the first and second output signals, wherein the buck converter is configured to turn off in response to an output of the NAND gate being de-asserted; and a linear voltage regulator configured to regulate the output voltage while the buck converter is turned off. ### Claim 12 (depends on 11) The device of claim 11, wherein the port controller is configured to: receive the first output signal indicating that the input voltage is above a first threshold voltage; generate a control signal for turning off the pass transistor in response to receiving the first output signal; receive the second output signal indicating that a gate voltage of the pass transistor is below a second threshold voltage; and turn off the buck converter in response to receiving the second output signal. ### Claim 13 (depends on 11) The device of claim 11, wherein a voltage rating of a high-side transistor of the buck converter is less than an automotive load dump voltage in response to the automotive battery being disconnected.