# US 10,312,906 B2 · Switch apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,312,906 B2 - Document ID: US10312906B2 - Status: Granted - Kind: B2 - Application number: 15/701,447 - Filed: 2017-09-12 - Published: 2018-03-22 - Granted: 2019-06-04 - Earliest claimed: 2016-09-16 - Assignees: Asahi Kasei Microdevices Corporation - Applicants: Asahi Kasei Microdevices Corporation - Inventors: Kenichi Sato; Atsuo Ito - Web page: https://patentgrep.com/patent/US10312906B2 ## CPC - H03K 17/693: Switching arrangements with several input- or output-terminals, e.g. multiplexers, distributors (logic circuits H03K19/00; code converters H03M5/00, H03M7/00) - H03K 17/0412: by measures taken in the control circuit - H03K 17/102: {in field-effect transistor switches} - H03K 17/162: {without feedback from the output circuit to the control circuit} - H03K 17/166: {Soft switching} - H03K 17/6874: {in a symmetrical configuration} - H03K 2017/307: {circuits simulating a diode, e.g. threshold zero} - H03K 2017/6878: {using multi-gate field-effect transistors} - H03K 2217/0018: Special modifications or use of the back gate voltage of a FET - H03K 2217/0054: Gating switches, e.g. pass gates - 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) ## Abstract A switch apparatus is provided, including: a main switch connected between first and second terminals, and electrically connecting or disconnecting the first and second terminals according to gate voltage applied to a gate terminal; a voltage output unit having a voltage divider including a first voltage-division resistance on the first terminal side and a second voltage-division resistance on the second terminal side, and outputting voltage corresponding to voltage of the first terminal and voltage of the second terminal if the main switch is caused to enter a connected state; a buffer outputting voltage following output voltage of the voltage output unit in a connected state of the main switch; and a switch control circuit supplying first voltage corresponding to output voltage of the buffer to the gate terminal, and supplying a second voltage corresponding to output voltage of the buffer to a bulk terminal of the main switch. ## Claims ### Claim 1 A switch apparatus comprising: a main switch that is connected between a first terminal and a second terminal and electrically connects or disconnects the first terminal and the second terminal according to gate voltage applied to a gate terminal; a voltage output unit that has a voltage divider including a first voltage-division resistance on the first terminal side and a second voltage-division resistance whose one end is connected to the second terminal side, and outputs voltage corresponding to voltage of the first terminal and voltage of the second terminal in response to the main switch entering a connected state; a buffer that outputs voltage following output voltage of the voltage output unit in a connected state of the main switch; and a switch control circuit that supplies first voltage corresponding to output voltage of the buffer to the gate terminal of the main switch, and supplies a second voltage corresponding to output voltage of the buffer to a bulk terminal of the main switch; wherein the voltage output unit: outputs an average voltage of voltage of the first terminal and voltage of the second terminal in response to the main switch entering a connected state, and outputs voltage corresponding to either the voltage of the first terminal or the voltage of the second terminal and to first reference potential in response to the main switch entering a disconnected state; wherein the voltage output unit has: a first output resistance having one end that is connected between the first voltage-division resistance and the second voltage-division resistance and another end that outputs output voltage of the voltage output unit, a second output resistance having one end that is connected to the other end of the first output resistance and another end to which the first reference potential is supplied, and a third sub-switch that is provided between the second output resistance and the first reference potential, and enters a disconnected state in response to the main switch entering a connected state, and enters a connected state in response to the main switch entering a disconnected state. ### Claim 2 (depends on 1) The switch apparatus according to claim 1, wherein the voltage output unit supplies first reference potential to an intermediate terminal between the first voltage-division resistance and the second voltage-division resistance in response to the main switch entering a disconnected state. ### Claim 3 (depends on 2) The switch apparatus according to claim 2, wherein the voltage output unit further has: a first sub-switch that is provided between the first terminal and the first voltage-division resistance or between the intermediate terminal and the first voltage-division resistance, and enters a connected state in response to the main switch entering a connected state, and enters a disconnected state in response to the main switch entering a disconnected state; and a second sub-switch that is provided between the second terminal and the second voltage-division resistance or between the intermediate terminal and the second voltage-division resistance, and enters a connected state in response to the main switch entering a connected state, and enters a disconnected state in response to the main switch entering a disconnected state. ### Claim 4 (depends on 1) The switch apparatus according to claim 1, wherein the voltage output unit has at least one of a first sub-switch that electrically connects or disconnects a first terminal side and an intermediate point between the first voltage-division resistance and the second voltage-division resistance and a second sub-switch that electrically connects or disconnects a second terminal side and the intermediate point, and the at least one of the first sub-switch and the second sub-switch enters a connected state in response to the main switch entering a connected state, and enters a disconnected state in response to the main switch entering a disconnected state. ### Claim 5 (depends on 1) The switch apparatus according to claim 1, wherein the voltage output unit has: a first sub-switch that electrically connects or disconnects a first terminal side and an intermediate point between the first voltage-division resistance and the second voltage-division resistance; and a second sub-switch that electrically connects or disconnects a second terminal side and the intermediate point, in response to the main switch entering a connected state, the first sub-switch and the second sub-switch enter a connected state, and in response to the main switch entering a disconnected state: in response to an electrical signal being input through the first terminal, the first sub-switch enters a connected state and the second sub-switch enters a disconnected state; and in response to an electrical signal being input through the second terminal, the first sub-switch enters a disconnected state, and the second sub-switch enters a connected state. ### Claim 6 (depends on 2) The switch apparatus according to claim 2, wherein the first reference potential is potential that causes a diode formed between a source terminal and bulk terminal of the main switch to enter an OFF-state. ### Claim 7 (depends on 1) The switch apparatus according to claim 1, wherein the switch control circuit: supplies, to the gate terminal, the first voltage obtained by adding non-zero offset voltage to the second voltage supplied to the bulk terminal if the main switch is caused to enter a connected state; and supplies, to the gate terminal, the first voltage which is the same as the second voltage supplied to the bulk terminal if the main switch is caused to enter a disconnected state. ### Claim 8 (depends on 7) The switch apparatus according to claim 7, wherein the main switch is an n-type semiconductor switch, and the offset voltage is a positive voltage. ### Claim 9 (depends on 8) The switch apparatus according to claim 8, wherein the main switch is provided in a p-well on a substrate surface. ### Claim 10 (depends on 7) The switch apparatus according to claim 7, wherein the main switch is a p-type semiconductor switch, and the offset voltage is a negative voltage. ### Claim 11 (depends on 10) The switch apparatus according to claim 10, wherein the main switch is provided in an n-well on a substrate surface. ### Claim 12 (depends on 1) The switch apparatus according to claim 1, wherein the first reference potential is potential that causes a diode formed between a source terminal and bulk terminal of the main switch to enter an OFF-state. ### Claim 13 (depends on 1) The switch apparatus according to claim 1, wherein the second voltage-division resistance is provided between the second terminal and the first voltage-division resistance.