# US 7,746,126 B2 · Load driving circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,746,126 B2 - Document ID: US7746126B2 - Status: Granted - Kind: B2 - Application number: 11/886,999 - Filed: 2006-03-07 - Published: 2009-08-27 - Granted: 2010-06-29 - Earliest claimed: 2005-03-29 - Assignees: Hiji High-Tech Co., Ltd. - Inventors: Takeda Koji - Web page: https://patentgrep.com/patent/US7746126B2 ## CPC - H03F 1/42: Modifications of amplifiers to extend the bandwidth - G09G 3/3688: {suitable for active matrices only} - H03F 3/3022: {CMOS common source output SEPP amplifiers (H03F3/3008 takes precedence)} - H03F 3/45183: {Long tailed pairs (H03F3/4521, H03F3/45237 take precedence)} - H03K 17/166: {Soft switching} - H03K 19/01721: {by means of a pull-up or down element} - G09G 2310/027: Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters - G09G 2320/0204: Compensation of DC component across the pixels in flat panels - H03F 2203/30015: An input signal dependent control signal controls the bias of an output stage in the SEPP - H03F 2203/45674: the LC comprising one current mirror - H03F: AMPLIFIERS - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - 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 To provide a load drive circuit that has a satisfactory phase characteristic and can be realized as a low-price LSI chip. A series circuit of nonlinear resistive elements (P2 and N3) and switch elements (N2 and P3) is inserted between control input terminals (GP1 and GN1) of output elements (P1 and N1) of a final amplifier (AMP0) and an output terminal (OUT) of the load drive circuit. The nonlinear resistive element has a nonlinear characteristic in which a resistance value decreases as an applied voltage value increases and the resistance value increases as the applied voltage value decreases. The switch elements are switching-controlled to selectively come into an ON state only in a high-electric potential period or a low-electric potential period of an input signal according to whether the output element is arranged on a high-electric potential side or a low-electric potential side in the final amplifier. ## Claims ### Claim 1 A load drive circuit comprising: an output terminal to which a load should be connected; an input terminal to which an input signal should be given; a final amplifier including an output element for driving the load; a preamplifier for driving the output element included in the final amplifier according to the input signal; and a phase compensator for improving a phase characteristic between input and output signal waveforms, an output signal of a non-inverting form appearing in the output terminal according to the input signal given to the input terminal, characterized in that the phase compensator is constituted by inserting series circuits of nonlinear resistive elements and switch elements between a control input terminal of the output element of the final amplifier and the output terminal of the load drive circuit, the nonlinear resistive element has a nonlinear characteristic in which a resistance value decreases as an applied voltage value increases and the resistance value increases as the applied voltage value decreases, and the switch elements are switching-controlled to selectively come into an ON state only in a high-electric potential period or a low-electric potential period of the input signal according to whether the output element is arranged on a high-electric potential side or a low-electric potential side in the final amplifier. ### Claim 2 (depends on 1) The load drive circuit according to claim 1, wherein the nonlinear resistive element is a transistor element that has a control input terminal and a pair of main terminals and is circuit-connected such that electric potential of this control input terminal follows electric potential of the output terminal of the load drive circuit. ### Claim 3 (depends on 1) The load drive circuit according to claim 1, wherein the final amplifier is constituted by a complimentarily-connected pair of output elements and the series circuits is inserted between a control input terminal of a high-electric potential side output element and the output terminal and between a control input terminal of a low-electric potential side output element and the output terminal, respectively. ### Claim 4 (depends on 1) The load drive circuit according to claim 1, wherein the final amplifier is constituted to connect a high-electric potential side output element and a load element or a low-electric potential side output element and a load element in series between a pair of power supply terminals and extract an output signal from a connection point thereof and the series circuits is inserted between a control input terminal of the high-electric potential side output element and the output terminal or between a control input terminal of the low-electric potential side output element and the output terminal. ### Claim 5 (depends on 4) The load drive circuit according to claim 4, wherein the load element is a constant current source constituted by one or two or more transistor elements. ### Claim 6 (depends on 1) The load drive circuit according to claim 1, wherein the preamplifier is an inverting amplifier that amplifies an electric potential difference between the input terminal and the output terminal and gives the electric potential difference to the output element of the final amplifier. ### Claim 7 (depends on 6) The load drive circuit according to claim 6, wherein the inverting amplifier is a differential amplifier of a current mirror type in which a constant current source is inserted in a common current path. ### Claim 8 (depends on 1) The load drive circuit according claim 1, wherein the preamplifier is a non-inverting buffer circuit that amplifies the input signal and a pull resistive element is inserted between a control input terminal and a power supply terminal of an output element. ### Claim 9 (depends on 8) The load drive circuit according to claim 8, wherein the non-inverting buffer circuit is a buffer circuit of a three-state type that can take a high-electric potential output state, a low-electric potential output state, and a high-impedance state. ### Claim 10 (depends on 8) The load drive circuit according to claim 8, wherein the pull resistive element is a poly resistor. ### Claim 11 (depends on 8) The load drive circuit according to claim 8, wherein the pull resistive element is a transistor element that has a control input terminal and a pair of main terminals and functions as a resistive element by mating the control input terminal conductive to one of the pair of main terminals. ### Claim 12 (depends on 8) The load drive circuit according to claim 8, wherein the pull resistive element is a constant current source constituted by one or two or more transistor elements. ### Claim 13 (depends on 1) The load drive circuit according to claim 1, wherein further comprising a control input terminal and a circuit for enabling/disabling an operation of the preamplifier and/or the phase compensator according to a control input signal given to the control input terminal.