# US 12,015,381 B2 · Methods and apparatus for driver calibration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,381 B2 - Document ID: US12015381B2 - Status: Granted - Kind: B2 - Application number: 18/450,123 - Filed: 2023-08-15 - Published: 2023-11-30 - Granted: 2024-06-18 - Earliest claimed: 2018-06-07 - Assignees: Semiconductor Components Industries, LLC - Applicants: Semiconductor Components Industries, LLC - Inventors: Seiji Takeuchi - Web page: https://patentgrep.com/patent/US12015381B2 ## CPC - H03F 1/30: Modifications of amplifiers to reduce influence of variations of temperature or supply voltage {or other physical parameters (in differential amplifiers H03F3/45479)} - G03B 3/10: Power-operated focusing - G03B 13/36: Autofocus systems - G05F 3/24: wherein the transistors are of the field-effect type only (G05F3/205, G05F3/26, G05F3/30 take precedence) - H02P 25/034: Voice coil motors (voice coil motors driven by DC H02P7/025) - H03F 1/301: {in MOSFET amplifiers (H03F1/303, H03F1/305, H03F1/308 take precedence)} - H03F 3/45: Differential amplifiers (differential sense amplifiers G11C7/062) - H03F 3/45183: {Long tailed pairs (H03F3/4521, H03F3/45237 take precedence)} - H03F 3/45748: {by using a feedback circuit} - G03B 2205/0053: Driving means for the movement of one or more optical element - H03F 2200/453: Controlling being realised by adding a replica circuit or by using one among multiple identical circuits as a replica circuit - H03F 2203/45048: Calibrating and standardising a dif amp - H03F 2203/45212: the differential amplifier being designed to have a reduced offset - H03M 1/1009: {Calibration} - H03F: AMPLIFIERS - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - G05F: SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C) ## Abstract Driver circuits, systems for driving actuators, and imaging systems with actuators. The driver circuit includes a current comparator circuit, a driver, and a replica circuit. The current comparator circuit includes a first node having a first voltage. The current comparator circuit also includes a second node having a second voltage. The driver includes a first terminal responsive to the second voltage. The driver also includes a second terminal connected to a reference voltage. The replica circuit includes a third terminal connected to the first node. The replica circuit also includes a fourth terminal connected to the second terminal of the driver. The replica circuit also includes a fifth terminal connected to the first terminal of the driver. ## Claims ### Claim 1 A circuit, comprising: a current comparator circuit including: a first node having a first voltage, and a second node having a second voltage; a driver including: a first terminal responsive to the second voltage, and a second terminal connected to a reference voltage; and a replica circuit including: a third terminal connected to the first node, a fourth terminal connected to the second terminal of the driver, and a fifth terminal connected to the first terminal of the driver. ### Claim 2 (depends on 1) The circuit of claim 1, wherein the replica circuit is configured to generate a replica current that is proportional to a drive current of the driver. ### Claim 3 (depends on 1) The circuit of claim 1, wherein the current comparator circuit further includes a first transistor and a second transistor connected in series with each other. ### Claim 4 (depends on 3) The circuit of claim 3, wherein the first node is located between the first transistor and the second transistor. ### Claim 5 (depends on 3) The circuit of claim 3, wherein the replica circuit further includes a third transistor, and wherein the second node is located between the second transistor and the third transistor. ### Claim 6 (depends on 1) The circuit of claim 1, wherein the replica circuit further includes a transistor having a drain terminal, a source terminal, a gate terminal, wherein the third terminal is the drain terminal, wherein the fourth terminal is the source terminal, and wherein the fifth terminal is the gate terminal. ### Claim 7 (depends on 1) The circuit of claim 1, wherein the replica circuit further includes a transistor and the third terminal is a drain terminal, the fourth terminal is a source terminal, and the fifth terminal is a gate terminal. ### Claim 8 A system, comprising: an actuator; and a control circuit configured to control the actuator and including: a current comparator circuit including: a first node having a first voltage, and a second node having a second voltage, a driver including: a first terminal responsive to the second voltage, and a second terminal connected to a reference voltage, and a replica circuit including: a third terminal connected to the first node, a fourth terminal connected to the second terminal of the driver, and a fifth terminal connected to the first terminal of the driver. ### Claim 9 (depends on 8) The system of claim 8, wherein the replica circuit is configured to generate a replica current that is proportional to a drive current of the driver. ### Claim 10 (depends on 8) The system of claim 8, wherein the current comparator circuit further includes a first transistor and a second transistor connected in series with each other. ### Claim 11 (depends on 10) The system of claim 10, wherein the first node is located between the first transistor and the second transistor. ### Claim 12 (depends on 10) The system of claim 10, wherein the replica circuit further includes a third transistor, and wherein the second node is located between the second transistor and the third transistor. ### Claim 13 (depends on 8) The system of claim 8, wherein the current comparator circuit is configured to generate a comparator output voltage at the second node. ### Claim 14 (depends on 8) The system of claim 8, wherein the replica circuit further includes a transistor having a drain terminal, a source terminal, a gate terminal, wherein the third terminal is the drain terminal, wherein the fourth terminal is the source terminal, and wherein the fifth terminal is the gate terminal. ### Claim 15 An imaging system, comprising: a lens; an actuator configured to adjust a position of the lens; a current comparator circuit including: a first node having a first voltage, and a second node having a second voltage; a driver configured to control the actuator and including: a first terminal responsive to the second voltage, and a second terminal connected to a reference voltage; and a replica circuit including: a third terminal connected to the first node, a fourth terminal connected to the second terminal of the driver, and a fifth terminal connected to the first terminal of the driver. ### Claim 16 (depends on 15) The imaging system of claim 15, wherein the replica circuit is configured to generate a replica current that is proportional to a drive current of the driver. ### Claim 17 (depends on 15) The imaging system of claim 15, wherein the current comparator circuit further includes a first transistor and a second transistor connected in series with each other. ### Claim 18 (depends on 17) The imaging system of claim 17, wherein the first node is located between the first transistor and the second transistor. ### Claim 19 (depends on 17) The imaging system of claim 17, wherein the replica circuit further includes a third transistor, and wherein the second node is located between the second transistor and the third transistor. ### Claim 20 (depends on 15) The imaging system of claim 15, wherein the current comparator circuit is configured to generate a comparator output voltage at the second node.