# US 2018/0323705 A1 · Charge pump circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323705 A1 - Document ID: US20180323705A1 - Status: Published application - Kind: A1 - Application number: 16/023,114 - Filed: 2018-06-29 - Published: 2018-11-08 - Earliest claimed: 2010-12-27 - Assignees: Cirrus Logic International Semiconductor Ltd. - Applicants: Cirrus Logic International Semiconductor Ltd. - Inventors: John P. Lesso; Peter J. Frith; John L. Pennock - Web page: https://patentgrep.com/patent/US20180323705A1 ## CPC - H02M 3/07: using capacitors charged and discharged alternately by semiconductor devices with control electrode {, e.g. charge pumps} - H02M 1/00: Details of apparatus for conversion - H02M 3/072: {adapted to generate an output voltage whose value is lower than the input voltage} - H03F 3/181: Low-frequency amplifiers, e.g. audio preamplifiers - H02M 1/0083: {Converters characterised by their input or output configuration} - H02M 1/009: {having two or more independently controlled outputs (for DC-DC converter with intermediate AC H02M3/33561)} - H02M 3/071: {adapted to generate a negative voltage output from a positive voltage source} - 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) - H03F: AMPLIFIERS ## Abstract A bipolar output charge pump circuit having a network of switching paths for selectively connecting an input node and a reference node for connection to an input voltage, a first pair of output nodes and a second pair of output nodes, and two pairs of flying capacitor nodes, and a controller for controlling the switching of the network of switching paths. The controller is operable to control the network of switching paths when in use with two flying capacitors connected to the two pairs of flying capacitor nodes, to provide a first bipolar output voltage at the first pair of output nodes and a second bipolar output voltage at the second pair of bipolar output nodes. ## Claims ### Claim 1 (canceled) ### Claim 2 A charge pump circuit, comprising: an input node for connection to an input voltage; a first pair of output nodes and a second pair of output nodes; flying capacitor nodes for connecting to at least two flying capacitors; a switch network for interconnecting said nodes; and a controller operable to control the switch network in a sequence of switch states to provide a first bipolar output voltage at the first pair of output nodes and a second bipolar output voltage at the second pair of output nodes; wherein the controller is operable to selectively control the sequence of switch states such that the first bipolar output voltage is selectively variable and the second bipolar output voltage is fixed. ### Claim 3 (depends on 2) A charge pump circuit as claimed in claim 2, wherein the controller is operable to selectively control the sequence of switch states such that the first bipolar output voltage is selectively variable between at least two of +/−3VV, +/−2VV, +/−VV, +/−VV/2, +/−VV/3, +/−VV/4, +/−VV/5 or +/−VV/6, where VV is the input voltage. ### Claim 4 (depends on 3) A charge pump circuit as claimed in claim 3, wherein the second bipolar output voltage is +/−VV where VV is the input voltage. ### Claim 5 (depends on 3) A charge pump circuit as claimed in claim 3, wherein the second bipolar output voltage is +/−VV where VV/2 is the input voltage. ### Claim 6 (depends on 2) A charge pump circuit as claimed in claim 2, wherein the controller is operable to selectively control the sequence of switch states in at least first and second modes, wherein in the first mode the first bipolar output voltage has a magnitude greater than the input voltage and in the second mode the first bipolar output voltage has a magnitude smaller than the input voltage. ### Claim 7 (depends on 1) A charge pump circuit as claimed in claim 1, wherein the controller is configured to control the switch network to provide said variable first bipolar output voltage and fixed second bipolar output voltage with two flying capacitors connected to respective ones of said flying capacitor nodes. ### Claim 8 (depends on 7) A charge pump circuit as claimed in claim 7, comprising a first flying capacitor connected between a first pair of said flying capacitor nodes and a second flying capacitor connected between a second pair of said flying capacitor nodes. ### Claim 9 (depends on 1) A charge pump circuit as claimed in claim 1, wherein: the first pair of output nodes comprises first and second output nodes and the second pair of output nodes comprises third and fourth output nodes; and the controller is configured to control the switch network to provide said variable first bipolar output voltage and fixed second bipolar output voltage with, in use, first and second reservoir capacitors connected between a reference node and the first and second output nodes respectively, and third and fourth reservoir capacitors connected between a reference node and the third and fourth output nodes respectively. ### Claim 10 (depends on 9) A charge pump circuit as claimed in claim 9, wherein the controller is operable to control the sequence of switch states such that first reservoir capacitor is recharged when a voltage at the first output node is smaller in magnitude than a first threshold, the second reservoir capacitor is recharged when a voltage at the second output node is smaller in magnitude than a second threshold, the third reservoir capacitor is recharged when a voltage at the third output node is smaller in magnitude than a third threshold, and the fourth reservoir capacitor is recharged when a voltage at the fourth output node is smaller in magnitude than a fourth threshold. ### Claim 11 (depends on 9) A charge pump circuit as claimed in claim 9, comprising said first and second reservoir capacitors connected between the reference node and the first and second output nodes respectively, and said third and fourth reservoir capacitors connected between the reference node and the third and fourth output nodes respectively. ### Claim 12 (depends on 1) A charge pump circuit as claimed in claim 1, implemented as an integrated circuit. ### Claim 13 (depends on 1) An audio output chain configured to receive an input audio signal and output an output audio signal for driving an audio load comprising: a charge pump circuit as claimed in claim 1. ### Claim 14 (depends on 13) An audio output chain as claimed in claim 13, comprising an audio amplifier configured to be powered by the first bipolar output voltage from the charge pump circuit. ### Claim 15 (depends on 14) An audio output chain as claimed in claim 14, comprising a further component configured to be powered by the second bipolar output voltage from the charge pump circuit. ### Claim 16 (depends on 15) An audio output chain as claimed in claim 15, wherein said further component comprises a digital-to-analogue converter. ### Claim 17 (depends on 14) An audio output chain as claimed in claim 14, wherein the controller of the charge pump circuit is configured to control the sequence of switch states so as to selective control the variable first bipolar output voltage based on an indication of a signal level of the input audio signal. ### Claim 18 (depends on 16) An audio output chain as claimed in claim 16, comprising an envelope detector configured to receive a version of the input audio signal and determine an envelope value as said indication of the signal level of the input audio signal. ### Claim 19 (depends on 1) An electronic device comprising a charge pump circuit as claimed in claim 1. ### Claim 20 A charge pump circuit, comprising: an input node for connection to an input voltage; a first pair of output nodes and a second pair of output nodes; flying capacitor nodes for connecting to at least two flying capacitors; a network of switching paths for interconnecting said nodes; and a controller operable to control the network of switching paths in a sequence of switching states to provide a first bipolar output voltage at the first pair of output nodes and a second bipolar output voltage at the second pair of output nodes; wherein the controller is operable to selectivity vary the sequence of switching states so as to selectively vary the first bipolar output voltage without varying the second bipolar output voltage. ### Claim 21 A charge pump circuit, comprising: an input node for connection to an input voltage; a first pair of output nodes and a second pair of output nodes; flying capacitor nodes for connecting to at least two flying capacitors; a switch network for interconnecting said nodes; and a controller operable to control the switch network to provide a first bipolar output voltage at the first pair of output nodes and a second bipolar output voltage at the second pair of output nodes; the controller being operable in at least a first mode and a second mode, wherein: the first bipolar output voltage has a magnitude in the first mode that is different to the magnitude of the first bipolar output voltage in the second mode; and the second bipolar output voltage has a magnitude in the first mode that is the same as the magnitude of the second bipolar output voltage in the second mode.