# US 2010/0164592 A1 · Level shift circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0164592 A1 - Document ID: US20100164592A1 - Status: Published application - Kind: A1 - Application number: 12/640,973 - Filed: 2009-12-17 - Published: 2010-07-01 - Earliest claimed: 2008-12-31 - Inventors: Hak-Soo Kim; Nam-Jin Song - Web page: https://patentgrep.com/patent/US20100164592A1 ## CPC - H03K 3/356113: {using additional transistors in the input circuit} - H03K 3/015: Modifications of generator to maintain energy constant - H03K 3/0375: {provided with means for increasing reliability; for protection; for ensuring a predetermined initial state when the supply voltage has been applied; for storing the actual state when the supply voltage fails (digital storage cells each combining volatile and non-volatile storage properties G11C14/00)} - H03K 3/356182: {with additional means for controlling the main nodes} - 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 level shift circuit. A level shift circuit may include a first voltage supply control unit connected to a first voltage terminal to control a supply of a first voltage via a first and/or second path according to statuses of first and/or second input signals inputted differentially, a second voltage supply control unit connected to a second voltage terminal to control a supply of a second voltage via a first and/or second path, a switching unit controlling a connection between first and second voltage supply control units on a first and/or second path, and/or a buffer unit outputting an output signal corresponding to a first voltage and/or a second voltage in response to a first potential outputted between a first voltage supply control unit and a switching unit and/or a second potential output between a second voltage supply control unit and a switching unit. ## Claims ### Claim 1 An apparatus comprising: a first voltage supply control unit connected to a first voltage terminal configured to control a supply of a first voltage through at least one of a first path and a second path according to statuses of a first input signal and a second input signal; a second voltage supply control unit connected to a second voltage terminal configured to control a supply of a second voltage through said at least one of said first path and said second path; a switching unit configured to control a connection between said first voltage supply control unit and said second voltage supply control unit on said at least one of said first path and said second path; and a buffer unit configured to output an output signal corresponding to at least one of said first voltage and said second voltage in response to at least one of a first potential output between said first voltage supply control unit and said switching unit and a second potential output between said second voltage supply control unit and said switching unit. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein said first voltage supply control unit comprises: a first transistor connected between said first switching unit and said first voltage terminal on said first path, said first transistor including a gate to receive said first input signal; and a second transistor connected between said first switching unit and said first voltage terminal on said second path, said second transistor including a gate to receive said second input signal. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein said second voltage supply control unit is configured to control said supply of said second voltage according to at least one of a presence and an absence of said supply of said first voltage through said first voltage supply control unit. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein said second voltage supply control unit comprises: a first transistor connected between said second voltage terminal and said switching unit on said first path, said first transistor including a gate connected to an output terminal of said first voltage supply control unit on said second path; and a second transistor connected between said second voltage terminal and said switching unit on said second path, said second transistor including a gate connected to an output terminal of said first voltage supply control unit on said first path. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein said second voltage supply control unit is configured to control said supply of said second voltage according to said statuses of said first input signal and said second input signal. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein said second voltage supply control unit comprises: a first transistor connected between said second voltage terminal and said switching unit on said first path, said first transistor including a gate to receive said first input signal; and a second transistor connected between said second voltage terminal and said switching unit on said second path, said first transistor including a gate to receive said second input signal. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein said switching unit is configured to control a connection between said first voltage supply unit and said second voltage supply unit according to at least one of a presence and an absence of said supply of said second voltage through said second voltage supply control unit. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein said switching unit comprises: a first transistor connected between said first supply control unit and said second voltage supply control unit on said first path, said first transistor controlled to be turned on according to at least one of a presence and an absence of said supply of said second voltage on said first path through said second voltage supply control unit; and a second transistor connected between said first voltage supply control unit and said second voltage supply control unit on said second path, said second transistor controlled to be turned on according to at least one of presence and an absence of said supply of said second voltage on said second path through said second voltage supply control unit. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein said switching unit comprises: a third transistor connected between a gate of said second transistor and said first voltage terminal, said third transistor including a gate connected to an output terminal on said second path of said second voltage supply control unit; and a fourth transistor connected between a gate of said first transistor and said first voltage terminal, said fourth transistor including a gate connected to an output terminal on said first path of said second voltage supply control unit. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein said switching unit is configured to control a connection between said first voltage supply control unit and said second voltage supply control unit according to statuses of said first input signal and said second input signal. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein said switching unit comprises: a first transistor connected between said first voltage supply control unit and said second voltage supply control unit on said first path, said first transistor including a gate to receive said first input signal; and a second transistor connected between said first voltage supply control unit and said second voltage supply control unit on said second path, said second transistor including a gate to receive said second input signal. ### Claim 12 (depends on 1) The apparatus of claim 1, wherein said switching unit is configured to control a connection between said first voltage supply control unit and said second voltage supply unit according to at least one of a presence and an absence of said supply of said first voltage through said first voltage supply control unit. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein said switching unit comprises: a first transistor connected between said first voltage supply control unit and said second voltage supply control unit on said first path, said first transistor including a gate connected to an output terminal on said first path of said first voltage supply control unit; and a second transistor connected between said first voltage supply control unit and second voltage supply control unit on said second path, said second transistor including a gate connected to an output terminal on said second path of said first voltage supply control unit. ### Claim 14 (depends on 1) The apparatus of claim 1, wherein said buffer unit comprises: a first transistor configured to selectively supply said first voltage as said output signal comprising a gate to receive said first potential output between said first voltage supply unit and said switching unit; and a second transistor configured to selectively supply said second voltage as an output signal comprising a gate to receive said second potential output between said second voltage supply unit and said switching unit. ### Claim 15 (depends on 1) The apparatus of claim 1, wherein said first voltage corresponds to a ground voltage and said second voltage corresponds to a power source voltage. ### Claim 16 A method comprising: forming a first voltage supply control unit connected to a first voltage terminal configured to control a supply of a first voltage through at least one of a first path and a second path according to statuses of a first input signal and a second input signal; forming a second voltage supply control unit connected to a second voltage terminal configured to control a supply of a second voltage through said at least one of said first path and said second path; forming a switching unit configured to control a connection between said first voltage supply control unit and said second voltage supply control unit on said at least one of said first path and said second path; and forming a buffer unit configured to output an output signal corresponding to at least one of said first voltage and said second voltage in response to at least one of a first potential output between said first voltage supply control unit and said switching unit and a second potential output between said second voltage supply control unit and said switching unit. ### Claim 17 (depends on 16) The method of claim 16, wherein said second voltage supply control unit is configured to at least one of control said supply of said second voltage according to at least one of a presence and an absence of said supply of said first voltage through said first voltage supply control unit; and control said supply of said second voltage according to said statuses of said first input signal and said second input signal. ### Claim 18 (depends on 16) The method of claim 16, wherein said switching unit is configured to at least one of: control a connection between said first voltage supply unit and said second voltage supply unit according to at least one of a presence and an absence of said supply of said second voltage through said second voltage supply control unit; control a connection between said first voltage supply control unit and said second voltage supply control unit according to statuses of said first input signal and said second input signal; and control a connection between said first voltage supply control unit and said second voltage supply unit according to at least one of a presence and an absence of said supply of said first voltage through said first voltage supply control unit. ### Claim 19 (depends on 16) The method of claim 16, wherein said buffer unit comprises: a first transistor configured to selectively supply said first voltage as said output signal comprising a gate to receive said first potential output between said first voltage supply unit and said switching unit; and a second transistor configured to selectively supply said second voltage as an output signal comprising a gate to receive said second potential output between said second voltage supply unit and said switching unit. ### Claim 20 (depends on 16) The method of claim 16, wherein said first voltage corresponds to a ground voltage and said second voltage corresponds to a power source voltage.