# US 8,542,063 B2 · Adaptive amplification circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,063 B2 - Document ID: US8542063B2 - Status: Granted - Kind: B2 - Application number: 13/196,873 - Filed: 2011-08-02 - Published: 2012-06-14 - Granted: 2013-09-24 - Earliest claimed: 2010-12-10 - Assignees: Novatek Microelectronics Corp. - Applicants: Xie-Ren Hsu; Chia-Hung Lin; Wei-Hsiang Hung - Inventors: Xie-Ren Hsu; Chia-Hung Lin; Wei-Hsiang Hung - Web page: https://patentgrep.com/patent/US8542063B2 ## CPC - H03F 3/45076: {characterised by the way of implementation of the active amplifying circuit in the differential amplifier} - H03F 1/0261: {with control of the polarisation voltage or current, e.g. gliding Class A} - H03F 3/45632: {in differential amplifiers with FET transistors as the active amplifying circuit (H03F3/4578 takes precedence)} - H03F 2203/45244: the differential amplifier contains one or more explicit bias circuits, e.g. to bias the tail current sources, to bias the load transistors - H03F 2203/45248: the dif amp being designed for improving the slew rate - H03F: AMPLIFIERS ## Abstract An adaptive amplification circuit is disclosed, which includes an operational amplifier including a variable bias current source for providing a variable bias current for the operational amplifier, a simulation unit for simulating operational characteristics of the operational amplifier and transforming a simulation input voltage to a simulation output voltage, and a bias control unit for generating a bias control signal to the variable bias current source according to the simulation output voltage so as to adjust the variable bias current. ## Claims ### Claim 1 An adaptive amplification circuit, comprising: an operational amplifier, comprising a variable bias current source for providing a variable bias current for the operational amplifier; a simulation unit for simulating operational characteristics of the operational amplifier, and transforming a simulation input voltage to a simulation output voltage reflecting the simulated operational characteristics of the operational amplifier; and a bias control unit for generating a bias control signal to the variable bias current source according to the simulation output voltage so as to adjust the variable bias current. ### Claim 2 (depends on 1) The adaptive amplification circuit of claim 1, wherein the operational characteristics of the operational amplifier comprises at least one of a charging characteristic and a discharging characteristic. ### Claim 3 (depends on 1) The adaptive amplification circuit of claim 1, wherein the simulation unit comprises at least one of an equivalent circuit and a physical circuit of the operational amplifier. ### Claim 4 (depends on 1) The adaptive amplification circuit of claim 1, wherein the simulation unit comprises: a first voltage-to-current circuit for transforming the simulation input voltage to a first current; and a simulation capacitor coupled between the first voltage-to-current circuit and a reference voltage terminal for generating the simulation output voltage. ### Claim 5 (depends on 4) The adaptive amplification circuit of claim 4, wherein a capacitance value of the simulation capacitor is substantially equal to an equivalent capacitance value of an internal capacitor of the operational amplifier. ### Claim 6 (depends on 1) The adaptive amplification circuit of claim 1, wherein the bias control unit generates the bias control signal according to a reference voltage, wherein the reference voltage is determined according to at least one voltage node of a loading device driven by the operational amplifier. ### Claim 7 (depends on 1) The adaptive amplification circuit of claim 1, wherein the bias control unit comprises: a reference voltage generation unit for generating a reference voltage; a comparator for comparing the simulation output voltage with the reference voltage to generate a comparison signal; and a bias generation unit for generating the bias control signal to the variable bias current source according to the comparison signal so as to adjust the variable bias current. ### Claim 8 (depends on 7) The adaptive amplification circuit of claim 7, wherein the reference voltage generation unit generates the reference voltage at various voltage levels according to a data comparison signal. ### Claim 9 (depends on 7) The adaptive amplification circuit of claim 7, wherein the reference voltage generation unit comprises: a voltage generator for generating a plurality of predefined reference voltages; and a multiplexer for selecting the reference voltage from the plurality of predefined reference voltages according to a data comparison signal. ### Claim 10 (depends on 9) The adaptive amplification circuit of claim 9, wherein the plurality of predefined reference voltages are respectively gamma voltages of a liquid crystal display. ### Claim 11 (depends on 7) The adaptive amplification circuit of claim 7, wherein when the simulation output voltage is lower than the reference voltage, the bias generation unit generates the bias control signal to increase the variable bias current according to the comparison signal. ### Claim 12 (depends on 7) The adaptive amplification circuit of claim 7, wherein when the simulation output voltage is higher than the reference voltage, the bias generation unit generates the bias control signal to decrease the variable bias current according to the comparison signal. ### Claim 13 (depends on 7) The adaptive amplification circuit of claim 7, wherein the bias generation unit comprises: a second voltage-to-current circuit for transforming the comparison signal to a second current; a current operating unit for generating an operating current according to the second current; and a bias control circuit for generating the bias control signal according to the operating current. ### Claim 14 (depends on 7) The adaptive amplification circuit of claim 7, wherein the bias generation unit comprises: a second voltage-to-current circuit for transforming the comparison signal to a second current; and a current operating unit for generating an operating current and the bias control signal according to the second current. ### Claim 15 An adaptive amplification circuit, comprising: an operational amplifier, comprising a variable bias current source for providing a variable bias current for the operational amplifier; a simulation unit for simulating at least one of a charging characteristic and a discharging characteristic, and transforming a simulation input voltage to a simulation output voltage; and a bias control unit, comprising: a reference voltage generation unit for generating a reference voltage; a comparator for comparing the simulation output voltage with the reference voltage to generate a comparison signal; and a bias generation unit for generating a bias control signal to the variable bias current source according to the comparison signal so as to adjust the variable bias current. ### Claim 16 (depends on 15) The adaptive amplification circuit of claim 15, wherein the simulation unit comprises: a first voltage-to-current circuit for transforming the simulation input voltage to a first current; and a simulation capacitor coupled between the first voltage-to-current circuit and a reference voltage terminal for generating the simulation output voltage. ### Claim 17 (depends on 15) The adaptive amplification circuit of claim 15, wherein the bias generation unit comprises: a second voltage-to-current circuit for transforming the comparison signal to a second current; and a current operating unit for generating an operating current according to the second current, wherein the bias control signal is generated in accordance with the operating current. ### Claim 18 An adaptive amplification circuit, comprising: an operational amplifier, comprising a variable bias current source for providing a variable bias current for the operational amplifier; a simulation unit for simulating operational characteristics of the operational amplifier, and transforming a simulation input voltage to a simulation output voltage, wherein the operational characteristics of the operational amplifier comprises at least one of a charging characteristic and a discharging characteristic; and a bias control unit for generating a bias control signal to the variable bias current source according to the simulation output voltage so as to adjust the variable bias current. ### Claim 19 An adaptive amplification circuit, comprising: an operational amplifier, comprising a variable bias current source for providing a variable bias current for the operational amplifier; a simulation unit for simulating operational characteristics of the operational amplifier, and transforming a simulation input voltage to a simulation output voltage, wherein the simulation unit comprises at least one of an equivalent circuit and a physical circuit of the operational amplifier; and a bias control unit for generating a bias control signal to the variable bias current source according to the simulation output voltage so as to adjust the variable bias current.