# US 6,760,238 B2 · Apparatus and method for DC/DC converter having high speed and accuracy > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,760,238 B2 - Document ID: US6760238B2 - Status: Granted - Kind: B2 - Application number: 10/279,604 - Filed: 2002-10-24 - Published: 2004-04-29 - Granted: 2004-07-06 - Earliest claimed: 2002-10-24 - Assignees: BC Systems, Inc - Inventors: Arthur Charych - Web page: https://patentgrep.com/patent/US6760238B2 ## CPC - H02M 3/33515: {with digital control} - 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 system and method for DC/DC conversion are provided in which a high accuracy digital pulse width modulator controller circuit controls a power switch to obtain a desired DC output. The control circuit amplifies the difference of a DC output sample in relation to voltage reference. The amplified difference is then compared with a portion of the DC output. The compared result is used for controlling the power switch. A ripple coming from the DC output side is overlaid upon either one of the inputs to the comparator depending upon the polarity of the ripple signal. ## Claims ### Claim 1 A digital pulse width modulator (PWM) control circuit, comprising: a) a first input being a sample of a DC output; b) a second input being coupled to the DC output and possessing a ripple signal in synchronization with a DC output component; c) a voltage reference for determining a desired DC output; d) an adjustment amplifier having a portion of the DC output and the voltage reference as inputs, thereby amplifying a first difference; and e) a comparator having the first input and the output of the adjustment amplifier as inputs thereto with the second input overlaying one of the comparator inputs, the comparator comparing a second difference; thereby a determination is made as to whether the DC output is above or below the desired DC output and a correction is performed to change the DC output to a set of values as close to the desired DC output as possible. ### Claim 2 (depends on 1) The circuit of claim 1 further comprising a power switch coupled to the output of the comparator, thereby the power switch switches a DC input on and off according to a PWM scheme for achieving the desired DC output. ### Claim 3 (depends on 1) The circuit of claim 1, wherein the DC output component is an output winding of a transformer. ### Claim 4 (depends on 1) The circuit of claim 1, wherein the DC output component includes an inductance. ### Claim 5 (depends on 1) The circuit of claim 1, wherein the first difference is a difference between the portion of the DC output and the voltage reference. ### Claim 6 (depends on 1) The circuit of claim 1, wherein the second difference is a difference between the first input and the output of the adjustment amplifier. ### Claim 7 A DC/DC converting system, comprising: a) a DC input power source disposed to be switched on and off periodically by a first power switch; b) at least one DC output receiving power from the DC input power source; c) at least one digital pulse width modulator (PWM) control circuit coupled to the DC output, the circuit including: i) a first input being a sample of the DC output; ii) a second input being coupled to the DC output and possessing a ripple signal in synchronization with a DC output component; iii) a voltage reference for determining a desired DC output; iv) an adjustment amplifier having a portion of the DC output and the voltage reference as inputs, thereby amplifying a first difference; and v) a comparator having the first input and the output of the adjustment amplifier as inputs thereto with the second input overlaying one of the comparator inputs, the comparator comparing a second difference; thereby a determination is made as to whether the DC output is above or below the desired DC output and a correction is performed to change the DC output to a set of values as close to the desired DC output as possible. ### Claim 8 (depends on 7) The system of claim 7, wherein the digital pulse width modulator (PWM) control circuit further comprising a power switch coupled to the output of the comparator, thereby the power switch switches a DC input on and off according to a PWM scheme for achieving the desired DC output. ### Claim 9 (depends on 7) The system of claim 7, wherein the power switch is the first power switch. ### Claim 10 (depends on 7) The system of claim 7, wherein the DC output component is an output winding of a transformer. ### Claim 11 (depends on 7) The system of claim 7, wherein the DC output component is an inductor wherein the input power source and the at least one output receiving power are electrically isolated within the digital pulse width modulator control circuit by an isolation device. ### Claim 12 (depends on 7) The system of claim 7, wherein the isolation device is an optical isolation device. ### Claim 13 (depends on 7) The system of claim 7, wherein the isolation device is a magnetic isolation device. ### Claim 14 (depends on 7) The system of claim 7, wherein the first difference is a difference between the portion of the DC output and the voltage reference. ### Claim 15 (depends on 7) The system of claim 7, wherein the second difference is a difference between the first input and the output of the adjustment amplifier. ### Claim 16 A method for controlling a DC/DC converter, comprising the steps of: a) providing a switchable DC input to generate at least one DC output; b) providing a voltage reference; c) amplifying a first difference between a portion of the DC output and the voltage reference; and d) comparing a second difference between a portion of the DC output and the amplified first difference; e) overlaying a ripple signal upon either the amplified first difference or the portion of the DC output. ### Claim 17 (depends on 16) The method of claim 16 further comprising providing a in which the ripple signal originates from the DC output.