# US 8,541,992 B2 · Voltage converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,992 B2 - Document ID: US8541992B2 - Status: Granted - Kind: B2 - Application number: 13/061,127 - Filed: 2009-08-18 - Published: 2011-06-30 - Granted: 2013-09-24 - Earliest claimed: 2008-08-29 - Assignees: NXP B.V. - Applicants: Hendrik Johannes Bergveld; Franciscus Adrianus Cornelis Maria Schoofs - Inventors: Hendrik Johannes Bergveld; Franciscus Adrianus Cornelis Maria Schoofs - Web page: https://patentgrep.com/patent/US8541992B2 ## CPC - H02M 3/07: using capacitors charged and discharged alternately by semiconductor devices with control electrode {, e.g. charge pumps} - 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) ## Abstract A DC voltage converter, comprising: a multi-ratio capacitive converter; a linear voltage regulator in series with the multi-ratio capacitive converter; and a controller; the controller arranged to control the ratio of the multi-ratio capacitive converter dependent upon the voltage difference across the linear voltage regulator. ## Claims ### Claim 1 A DC voltage converter, comprising: a multi-ratio capacitive converter; a linear voltage regulator in series with the multi-ratio capacitive converter; and a controller; the controller arranged to control the ratio between the input voltage of the multi-ratio capacitive converter and the output voltage of the multi-ratio capacitive converter dependent upon the voltage difference between the output voltage of the linear voltage regulator and the input voltage of the linear voltage regulator. ### Claim 2 (depends on 1) A DC voltage converter according to claim 1, wherein the controller controls the ratio of the multi-ratio capacitive converter such as to maintain the voltage difference across the linear voltage regulator within a predetermined voltage window. ### Claim 3 (depends on 1) A DC voltage converter according to claim 1, wherein the predetermined voltage window is between a minimum voltage which is the drop-out voltage or close to and above the drop-out voltage of the linear voltage regulator, and a maximum voltage. ### Claim 4 (depends on 3) A DC voltage converter according to claim 3, wherein the maximum voltage is dependent on the ratio of the multi-ratio capacitive converter. ### Claim 5 (depends on 1) A DC voltage converter according to claim 1, wherein the controller controls the ratio of the multi-ratio capacitive converter such as to minimise the voltage difference across the linear voltage regulator. ### Claim 6 (depends on 1) A DC voltage converter according to claim 1, wherein the controller controls the ratio of the multi-ratio capacitive converter such as to control the voltage difference across the linear voltage regulator to be close to and above the drop-out voltage of the linear voltage regulator. ### Claim 7 (depends on 1) A DC voltage converter according to any of claim 1, wherein the controller comprises an analogue to digital converter and a digital processor. ### Claim 8 (depends on 1) A DC voltage converter according to claim 1, wherein the controller comprises an internal state machine. ### Claim 9 (depends on 1) A DC voltage converter according to claim 1, wherein the multi-ratio capacitive converter has four different ratios. ### Claim 10 (depends on 1) A DC voltage converter according to claim 1, further comprising means for accommodating ripple on the output of the multi-ratio capacitive converter. ### Claim 11 A method of converting DC voltage, the method comprising: inputting an input voltage to a multi-ratio capacitive converter; the multi-ratio capacitive converter converting the input voltage to an intermediate voltage; feeding the intermediate voltage to a linear voltage regulator and also to a controller; the linear voltage regulator regulating the intermediate voltage to an output voltage; feeding the output voltage to the controller and also providing the output voltage as the overall output voltage; and the controller controlling the ratio of between the input voltage of the multi-ratio capacitive converter and the intermediate voltage of the multi-ratio capacitive converter dependent upon the difference between the output voltage of the linear voltage regulator and the intermediate voltage of the multi-ratio capacitive converter. ### Claim 12 (depends on 11) A method according to claim 11, wherein the controller controls the ratio of the multi-ratio capacitive converter such as to maintain the difference between the output voltage and the intermediate voltage within a predetermined voltage window. ### Claim 13 (depends on 12) A method according to claim 12, wherein the predetermined voltage window is between a minimum voltage which is the drop-out voltage or close to and above the drop-out voltage of the linear voltage regulator, and a maximum voltage. ### Claim 14 (depends on 11) A method according to claim 11, wherein the controller controls the ratio of the multi-ratio capacitive converter such as to minimise the difference between the output voltage and the intermediate voltage. ### Claim 15 (depends on 11) A method according to claim 11, wherein the controller controls the ratio of the multi-ratio capacitive converter such as to control the difference between the output voltage and the intermediate voltage to be close to and above the drop-out voltage of the linear voltage regulator.