# US 7,609,114 B2 · Voltage generating apparatus and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,114 B2 - Document ID: US7609114B2 - Status: Granted - Kind: B2 - Application number: 12/153,865 - Filed: 2008-05-27 - Published: 2009-03-05 - Granted: 2009-10-27 - Earliest claimed: 2007-09-04 - Assignees: uPI Semiconductor Corp. - Inventors: Chung-An Hsieh; Cheng-Tao Li - Web page: https://patentgrep.com/patent/US7609114B2 ## CPC - H03F 1/0216: {Continuous control} - H03F: AMPLIFIERS ## Abstract The invention provides a voltage generating apparatus for powering at least one amplifier. The voltage generating apparatus comprises a voltage source, a switched capacitor voltage converter and a voltage detector. The voltage source supplies a first voltage to a positive voltage input terminal of the at least one amplifier. The first voltage is a positive DC voltage. The switched capacitor voltage converter is coupled to the voltage source for outputting an output voltage to a negative voltage input terminal of the at least one amplifier according to the first voltage and a predetermined voltage. The output voltage is a negative DC voltage. The voltage detector is coupled to the switched capacitor voltage converter for determining a switching frequency corresponding to the predetermined voltage according to the output voltage. The switched capacitor voltage converter increases the output voltage when the switching frequency is decreased and decreases the output voltage when the switching frequency is increased. ## Claims ### Claim 1 A voltage generating apparatus for driving at least one amplifier comprising: a voltage source for providing a first voltage, wherein the first voltage is a positive DC voltage outputted to a positive voltage input terminal of the at least one amplifier; a switched capacitor voltage converter coupled to the voltage source for outputting an output voltage to a negative voltage input terminal of the at least one amplifier according to the first voltage and a predetermined voltage, wherein the output voltage is a negative DC voltage; and a voltage detector coupled to the switched capacitor voltage converter for determining a switching frequency corresponding to the predetermined voltage according to the output voltage, wherein the switched capacitor voltage converter increases the output voltage when the switching frequency is decreased and decreases the output voltage when the switching frequency is increased. ### Claim 2 (depends on 1) The voltage generating apparatus as claimed in claim 1, wherein the first voltage and the output voltage are supplied to the at least one amplifier for audio signal amplification. ### Claim 3 (depends on 1) The voltage generating apparatus as claimed in claim 1, wherein the predetermined voltage is inversely proportional to the switching frequency. ### Claim 4 (depends on 3) The voltage generating apparatus as claimed in claim 3, wherein the output voltage is determined by the following formula: Vout=−Vin+Vc, wherein Vout is the output voltage, Vin is the first voltage and Vc is the predetermined voltage. ### Claim 5 (depends on 1) The voltage generating apparatus as claimed in claim 1, wherein the voltage generating apparatus further comprises a current source controller coupled to the switched capacitor voltage converter for supplying an extra voltage to directly adjust the output voltage. ### Claim 6 (depends on 5) The voltage generating apparatus as claimed in claim 5, wherein the output voltage is set as a function of the first voltage, the predetermined voltage and the extra voltage, according to the following formula: Vout=−Vin+Vc+(+/−Vei), wherein Vout is the output voltage, Vin is the first voltage, Vc is the predetermined voltage, and Vei is the extra voltage. ### Claim 7 (depends on 1) The voltage generating apparatus as claimed in claim 1, wherein the at least one amplifier is an operational amplifier. ### Claim 8 A voltage generating method for driving at least one amplifier comprising: providing a first voltage to a positive voltage input terminal of the at least one amplifier, wherein the first voltage is a positive DC voltage; generating an output voltage according to the first voltage and a predetermined voltage, wherein the output voltage is a negative DC voltage; supplying the output voltage to a negative voltage input terminal of the at least one amplifier; and determining a switching frequency corresponding to the predetermined voltage according to the output voltage, wherein the output voltage is increased when the switching frequency is decreased and is decreased when the switching frequency is increased. ### Claim 9 (depends on 8) The voltage generating method as claimed in claim 8, wherein the first voltage and the output voltage are supplied to the at least one amplifier for audio signal amplification. ### Claim 10 (depends on 8) The voltage generating method as claimed in claim 8, wherein the predetermined voltage is inversely proportional to the switching frequency. ### Claim 11 (depends on 10) The voltage generating method as claimed in claim 10, wherein the output voltage is determined by the following formula: Vout=−Vin+Vc, wherein Vout is the output voltage, Vin is the first voltage and Vc is the predetermined voltage. ### Claim 12 (depends on 8) The voltage generating method as claimed in claim 8, further comprising: supplying an extra voltage to directly adjust the output voltage. ### Claim 13 (depends on 12) The voltage generating method as claimed in claim 12, wherein the output voltage is set as a function of the first voltage, the predetermined voltage and the extra voltage, according to the following formula: Vout=−Vin+Vc+(+/−Vei), wherein Vout is the output voltage, Vin is the first voltage, Vc is the predetermined voltage, and Vei is the extra voltage. ### Claim 14 (depends on 8) The voltage generating method as claimed in claim 8, wherein the at least one amplifier is an operational amplifier.