# US 9,438,118 B2 · Efficient boost-buck converter and control method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,118 B2 - Document ID: US9438118B2 - Status: Granted - Kind: B2 - Application number: 14/159,987 - Filed: 2014-01-21 - Published: 2014-07-31 - Granted: 2016-09-06 - Earliest claimed: 2013-01-29 - Assignees: Silergy Semiconductor Technology (Hangzhou) LTD - Applicants: Silergy Semiconductor Technology (Hangzhou) LTD - Inventors: Wei Chen - Web page: https://patentgrep.com/patent/US9438118B2 ## CPC - H02M 3/1584: {with a plurality of power processing stages connected in parallel} - H02M 3/1582: {Buck-boost converters (H02M3/1584 takes precedence)} - 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 In one embodiment, a boost-buck converter can include: (i) first and second switches coupled in series between input and an output of the boost-buck converter; (ii) a first inductor coupled to the input and third and fourth switches, where the third switch is coupled to ground, and the fourth switch is coupled to the output; (iii) a second inductor coupled to the output and a common node of the first and second switches; and (iv) a control circuit configured to control switching of the first, second, third, and fourth switches according to the input and output voltages, such that the boost-buck converter operates in at least one of: a buck mode and a boost mode. ## Claims ### Claim 1 A method of controlling a boost-buck converter, the method comprising: a) receiving, by a control circuit, an input voltage from an input terminal of said boost-buck converter; b) receiving, by said control circuit, an output voltage from an output terminal of said boost-buck converter; c) controlling, by said control circuit, switching operations of first, second, third, and fourth switches of said boost-buck converter according to said input and output voltages such that said boost-buck converter operates in at least one of: a buck mode and a boost mode; and d) wherein said boost-buck converter comprises said first switch directly connected to said input terminal and to a first node, said second switch directly connected to said first node and to a ground terminal, a first inductor directly connected to said input terminal and to a second node, said third switch directly connected to said second node and to said ground terminal, said fourth switch directly connected to said second node and to said output terminal, and a second inductor directly connected to said first node and to said output terminal. ### Claim 2 (depends on 1) The method of claim 1, further comprising: a) controlling said third and fourth switches to be off, and controlling switching of said first and second switches such that said boost-buck converter operates in said buck mode when said input voltage is greater than said output voltage; and b) controlling said first and second switches to be off, and controlling switching of said third and fourth switches such that said boost-buck converter operates in said boost mode when said input voltage is less than said output voltage. ### Claim 3 (depends on 1) The method of claim 1, wherein said first and second inductors are two independent inductors. ### Claim 4 (depends on 1) The method of claim 1, wherein said first and second inductors are coupled inductors. ### Claim 5 (depends on 1) The method of claim 1, wherein: a) when said boost-buck converter operates in said boost mode, said first switch is configured to use reverse blocking; and b) when said boost-buck converter operates in said buck mode, said fourth switch is configured to use reverse blocking. ### Claim 6 A boost-buck converter, comprising: a) a first switch directly connected to a first node and to an input terminal of said boost-buck converter; b) a second switch directly connected to said first node and to a ground terminal; c) a first inductor directly connected to said input terminal and to a second node; d) a third switch directly connected to said second node and to said ground terminal; e) a fourth switch directly connected to said second node and to an output terminal of said boost-buck converter; f) a second inductor directly connected to said first node and to said output terminal; and g) a control circuit configured to receive an input voltage from said input terminal and an output voltage from said output terminal, and to control switching operations of said first, second, third, and fourth switches according to said input and output voltages, such that said boost-buck converter operates in at least one of: a buck mode and a boost mode. ### Claim 7 (depends on 6) The boost-buck converter of claim 6, wherein: a) said control circuit is configured to control said third and fourth switches to be off, and switching of said first and second switches such that said boost-buck converter operates in said buck mode when said control circuit detects that said input voltage is greater than said output voltage; and b) said control circuit is configured to control said first and second switches to be off, and switching of said third and fourth switches such that said boost-buck converter operates in said boost mode when said control circuit detects that said input voltage is less than said output voltage. ### Claim 8 (depends on 6) The boost-buck converter of claim 6, wherein said first and second inductors are two independent inductors. ### Claim 9 (depends on 6) The boost-buck converter of claim 6, wherein said first and second inductors are coupled together. ### Claim 10 (depends on 6) The boost-buck converter of claim 6, wherein: a) said first switch is configured to use reverse blocking when said boost-buck converter operates in said boost mode; and b) said fourth switch is configured to use reverse blocking when said boost-buck converter operates in said buck mode. ### Claim 11 (depends on 6) The boost-buck converter of claim 6, further comprising an output capacitor directly connected to said output terminal and to said ground terminal. ### Claim 12 (depends on 6) The boost-buck converter of claim 6, wherein each of said first and second inductors is not directly connected to said ground terminal. ### Claim 13 (depends on 6) The boost-buck converter of claim 6, wherein said second inductor is directly connected to said output terminal with no other devices therebetween. ### Claim 14 (depends on 1) The method of claim 1, wherein said boost-buck converter comprises an output capacitor directly connected to said output terminal and to said ground terminal. ### Claim 15 (depends on 1) The method of claim 1, wherein each of said first and second inductors is not directly connected to said ground terminal. ### Claim 16 (depends on 1) The method of claim 1, wherein said second inductor is directly connected to said output terminal with no other devices therebetween.