# US 2014/0191740 A1 · Voltage Converting LED Circuit with Switched Capacitor Network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0191740 A1 - Document ID: US20140191740A1 - Status: Published application - Kind: A1 - Application number: 12/611,870 - Filed: 2009-11-03 - Published: 2014-07-10 - Earliest claimed: 2009-11-03 - Assignees: Advanced Analogic Technologies, Inc. - Inventors: Bruno Ferrario; Yun Tung Sien - Web page: https://patentgrep.com/patent/US20140191740A1 ## CPC - H02M 3/156: with automatic control of output voltage or current, e.g. switching regulators - H02M 1/36: Means for starting or stopping converters - H05B 45/20: Controlling the colour of the light - H05B 45/375: using buck topology - H05B 45/38: using boost topology - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract A Voltage Converting LED Circuit with Switched Capacitor Network contains a 2-way MOSFET switch that connects a capacitor network to the output of an error amplifier, thereby enabling the error amplifier to resume operation quickly after the off-time segment of a PWM cycle. The switch is controlled synchronously with current sinks controlling brightness and color levels. In a preferred embodiment, multiple serially connected strings of LED's can be controlled simultaneously via one switch. ## Claims ### Claim 1 A circuit that comprises: a DC-to-DC voltage converter that comprises an inductor, wherein the DC-to-DC voltage converter is said to be in an active state while it supplies a variable output voltage to the monitored sub-circuits, and is said to be in an inactive state otherwise; an operational amplifier that comprises an input coupled to a voltage reference, one or more inputs configured to be representative of voltages within the monitored sub-circuits, and an output; a current mode PWM loop sub-circuit configured to control the DC-to-DC voltage converter based on the output of the operational amplifier and one or more measurements taken from within the DC-to-DC voltage converter; a compensation RC network that comprises a resistor and a capacitor; a transmission gate that is configured to allow a connection between the compensation RC network and the output of the operational amplifier when the DC-to-DC voltage converter is in the active state, and to prevent a connection between the compensation RC network and the output of the operational amplifier when the DC-to-DC voltage converter is in the inactive state. ### Claim 2 (depends on 1) A circuit as in claim 1 wherein the DC-to-DC voltage converter is generally configured as a boost converter. ### Claim 3 (depends on 2) A circuit as in claim 2 wherein the DC-to-DC voltage converter further comprises two MOSFET switches that are controlled by the current mode PWM loop sub-circuit. ### Claim 4 (depends on 2) A circuit as in claim 2 wherein the DC-to-DC voltage converter further comprises a diode and a MOSFET switch, the MOSFET switch being controlled by the current mode PWM loop sub-circuit. ### Claim 5 (depends on 1) A circuit as in claim 1 wherein the DC-to-DC voltage converter is generally configured as a Buck converter. ### Claim 6 (depends on 5) A circuit as in claim 5 wherein the DC-to-DC voltage converter further comprises a diode and a MOSFET switch. ### Claim 7 (depends on 1) A circuit as in claim 1 wherein the current mode PWM loop sub-circuit comprises: a comparator; an oscillator; and a driver logic module configured to control elements of the DC-to-DC voltage converter based on connections to the comparator and the oscillator. ### Claim 8 (depends on 7) A circuit as in claim 7 wherein the DC-to-DC voltage converter is generally configured as a boost converter. ### Claim 9 (depends on 7) A circuit as in claim 7 wherein the DC-to-DC voltage converter is generally configured as a Buck converter. ### Claim 10 (depends on 7, 8) A circuit as in claim 7, 8, or 9 wherein the DC-to-DC voltage converter is put into a configuration whereby the current through the inductor is increasing upon a signal from the oscillator, and is put into a configuration whereby the current through the inductor is decreasing when the current passing through the inductor exceeds a level determined by the output of the operational amplifier. ### Claim 11 A method of regulating the output voltage of a DC-to-DC voltage converter that comprises an inductor, the method comprising: monitoring one or more voltages within one or more monitored sub-circuits, each monitored sub-circuit connected to the output of the DC-to-DC converter; using an operational amplifier to amplify the difference between a reference voltage and one or more voltages that are representative of the monitored voltages; regulating the output voltage of the DC-to-DC converter in response to the output of the operational amplifier; connecting the output of the operational amplifier to a network that comprises a resistor and a capacitor when the DC-to-DC converter is supplying a variable output voltage to the monitored sub-circuits, and preventing said connection otherwise. ### Claim 12 (depends on 11) A method as in claim 11 wherein the DC-to-DC converter is generally configured as a boost converter. ### Claim 13 (depends on 11) A method as in claim 11 wherein the DC-to-DC voltage converter is generally configured as a Buck converter. ### Claim 14 (depends on 11, 12) A method as in claim 11, 12, or 13 that further comprises putting the DC-to-DC voltage converter into a configuration whereby the current through the inductor is increasing upon a signal from an oscillator, and putting the DC-to-DC voltage converter into a configuration whereby the current through the inductor is decreasing when the current passing through the inductor exceeds a level determined by the output of the operational amplifier.