# US 2019/0245341 A1 · Over voltage/energy protection apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0245341 A1 - Document ID: US20190245341A1 - Status: Published application - Kind: A1 - Application number: 16/151,355 - Filed: 2018-10-04 - Published: 2019-08-08 - Earliest claimed: 2018-02-07 - Assignees: Mediatek Inc. - Applicants: Mediatek Inc. - Inventors: Wei-Yu Ma - Web page: https://patentgrep.com/patent/US20190245341A1 ## CPC - H02H 7/20: for electronic equipment (for converters H02H7/10; for electric measuring instruments G01R1/36; for DC voltage or current semiconductor regulators G05F1/569; for amplifiers H03F1/52; for electronic switching circuits H03K17/08) - H02H 9/04: responsive to excess voltage (lightning arrestors H01C7/12, H01C8/04, H01G9/18, H01T) - H02H 9/041: {using a short-circuiting device} - H02H 9/046: {responsive to excess voltage appearing at terminals of integrated circuits} - H03K 17/0822: {in field-effect transistor switches} - H03K 17/74: by the use, as active elements, of diodes (by the use of more than one type of semiconductor device H03K17/567; by the use of tunnel diodes H03K17/58; by the use of negative resistance diodes H03K17/70) - H03K 2217/0081: Power supply means, e.g. to the switch driver - 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) - 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 An EOS/ESD protection apparatus includes a voltage detection circuit, a controlling circuit having a switch unit, an inverter circuit, and a clamp transistor. The voltage detection circuit is configured to detect whether an over voltage event occurs in a power supply line to generate a switch control signal. The switch unit is turned on/off to generate a voltage control signal according to the switch control signal. The inverter circuit has an output and an input coupled to the voltage control signal transmitted from the controlling circuit. The clamp transistor has a control terminal coupled to the output of the inverter and is configured to be turned on when the over voltage event occurs in the power supply line. ## Claims ### Claim 1 An over voltage/energy protection apparatus, comprising: a voltage detection circuit, configured to detect whether an over voltage event occurs in a power supply line to generate a switch control signal; a controlling circuit having a switch unit coupled to the voltage detection circuit, the switch unit being turned on/off to generate a voltage control signal according to the switch control signal; an inverter circuit having an output and an input coupled to the voltage control signal transmitted from the controlling circuit; and a clamp transistor having a control terminal coupled to the output of the inverter, configured to be turned on when the over voltage event occurs in the power supply line. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the voltage detection circuit is arranged to generate the switch control signal with a voltage lower than a particular voltage threshold when detecting that no over voltage events occur in the power supply line, and is arranged to generate the switch control signal with another voltage higher than the particular voltage threshold when detecting that the over voltage event occurs in the power supply line. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the particular voltage threshold is a threshold voltage of a transistor. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the voltage detection circuit comprises: at least one first diode having an anode coupled to the power supply line; and a first transistor having a control terminal coupled to the power supply line, a first terminal coupled to a cathode of the at least one first diode, and a second terminal coupled to a ground level; wherein the switch control signal is generated at the first terminal of the first transistor. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the voltage detection circuit further comprises: a resistor circuit, disposed between the second terminal of the first transistor and the ground level, the second terminal of the first transistor being connected to the ground level via the resistor circuit. ### Claim 6 (depends on 4) The apparatus of claim 4, wherein the at least one diode comprises a plurality of diodes connected in series. ### Claim 7 (depends on 4) The apparatus of claim 4, wherein the voltage detection circuit further comprises: a PMOS transistor having a control terminal coupled to the ground level, a first terminal coupled to the power supply line, and a second terminal coupled to the anode of the at least one diode, the PMOS transistor being coupled between the power supply line and the at least one diode. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the voltage detection circuit comprises: a plurality of first diodes connected in series, the plurality of first diodes having an anode coupled to the power supply line and a cathode coupled to a first transistor; and the first transistor having a control terminal coupled to the power supply line, a first terminal coupled to the cathode of the plurality of first diodes, and a second terminal coupled to a ground level; wherein the switch control signal is generated at a cathode of one diode among the plurality of first diodes. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the voltage detection circuit comprises: at least one first diode having an anode coupled to the power supply line; and at least one second diode having an anode coupled to a cathode of the at least one first diode, and a cathode coupled to a ground level; wherein the switch control signal is generated at the anode of the at least one second diode. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the at least one first diode comprises a plurality of first diodes connected in series. ### Claim 11 (depends on 9) The apparatus of claim 9, wherein the voltage detection circuit further comprises: a PMOS transistor having a control terminal coupled to the ground level, a first terminal coupled to the power supply line, and a second terminal coupled to the anode of the at least one first diode, the PMOS transistor being coupled between the power supply line and the at least one first diode. ### Claim 12 (depends on 9) The apparatus of claim 9, wherein the at least one second diode comprises a plurality of second diodes connected in series, and the switch control signal is generated at an intermediate node between the at least one first diode and the plurality of second diodes. ### Claim 13 (depends on 1) The apparatus of claim 1, wherein the voltage detection circuit comprises: a PMOS transistor having a control terminal coupled to a ground level, a first terminal coupled to the power supply line, and a second terminal coupled to at least one second diode; and the at least one second diode having an anode coupled to the second terminal of the PMOS transistor and a cathode coupled to the ground level; wherein the switch control signal is generated at an anode of one diode among the at least one second diode. ### Claim 14 (depends on 1) The apparatus of claim 1, wherein the controlling circuit comprises: a conductive unit having a first terminal coupled to the power supply line and a second terminal; wherein the switch unit is a second transistor having a control terminal coupled to the switch control signal, a first terminal coupled to the second terminal of the conductive circuit unit, and a second terminal coupled to a ground level; the switch control signal is arranged to turn on/off the second transistor to generate the voltage control signal at the first terminal of the second transistor. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein the conductive unit is a resistor coupled between the power supply line and the second transistor. ### Claim 16 (depends on 14) The apparatus of claim 14, wherein the conductive unit comprises a PMOS transistor having a gate coupled to the ground level, a source coupled to the power supply line, and a drain coupled to the first terminal of the second transistor. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the conductive unit comprises a PMOS transistor having a gate coupled to the switch control signal, a source coupled to the power supply line, and a drain coupled to the first terminal of the second transistor. ### Claim 18 (depends on 16) The apparatus of claim 16, wherein the conductive unit further comprises a resistor coupled between the drain of the PMOS transistor and the first terminal of the second transistor.