# US 8,569,992 B2 · Stepper motor controller and method for controlling same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,569,992 B2 - Document ID: US8569992B2 - Status: Granted - Kind: B2 - Application number: 13/047,801 - Filed: 2011-03-15 - Published: 2011-12-01 - Granted: 2013-10-29 - Earliest claimed: 2011-03-15 - Assignees: Freescale Semiconductor, Inc. - Applicants: Zhihong Cheng; Zhijun Chen; Shixiang Nie - Inventors: Zhihong Cheng; Zhijun Chen; Shixiang Nie - Web page: https://patentgrep.com/patent/US8569992B2 ## CPC - H02P 8/12: Control or stabilisation of current - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract A stepper motor controller includes control circuitry with control outputs and individual driver pulse width modulation (PWM) circuitry with individual driver PWM outputs and modulation control inputs coupled to the control outputs. There is a group of individual drivers, each one having an input coupled to one of the PWM outputs, and an output coupled to an individual driver terminal of the controller. There is common driver PWM circuitry having a common driver PWM output. A common driver having a common driver input is coupled to the common driver PWM output and a common driver output is coupled to a common driver terminal of the controller. When a coil is connected between respective driver terminals and the common driver terminal, individual PWM driver currents are supplied to the coils from the individual driver terminals and a common PWM driver current is supplied to the coils from the common driver terminal. ## Claims ### Claim 1 A stepper motor controller for controlling one or more stepper motors, wherein the stepper motor controller has individual driver terminals and a common driver terminal, the stepper motor controller comprising: control circuitry having control outputs; individual driver pulse width modulation (PWM) circuitry having individual driver PWM outputs and modulation control inputs coupled to respective said control outputs; a group of individual drivers, each individual driver in the group having an individual driver input coupled to a respective one of the individual driver PWM outputs, and an individual driver output coupled to one of the individual driver terminals of the controller; common driver PWM circuitry having a common driver PWM output; and a common driver having a common driver input coupled to the common driver PWM output, and a common driver output coupled to the common driver terminal of the controller, wherein when one or more stepper motor field coils are connected between respective individual driver terminals and the common driver terminal, individual PWM driver currents are supplied to the stepper motor field coils from the individual driver terminals, and a common PWM driver current is supplied to the stepper motor field coils from the common driver terminal. ### Claim 2 (depends on 1) The stepper motor controller of claim 1, wherein the individual driver PWM outputs include PWM control signals that control the individual PWM driver currents supplied by the individual drivers. ### Claim 3 (depends on 2) The stepper motor controller of claim 2, wherein the common driver PWM output includes a PWM control signal that controls the common PWM driver current supplied by the common driver. ### Claim 4 (depends on 3) The stepper motor controller of claim 3, wherein the individual PWM driver currents flow from at least one of the individual driver outputs and into the common driver output. ### Claim 5 (depends on 3) The stepper motor controller of claim 3, wherein, the common PWM driver current flows from the common driver output and into at least one of the individual driver outputs. ### Claim 6 (depends on 3) The stepper motor controller of claim 3, wherein each individual driver and the common driver includes series connected complementary transistors coupled between power supply nodes. ### Claim 7 (depends on 3) The stepper motor controller of claim 3, wherein the common driver PWM circuitry has a common control input coupled to one of the control outputs and wherein the common PWM driver current has a duty cycle selectable between 40% to 60%. ### Claim 8 (depends on 3) The stepper motor controller of claim 3, wherein the common driver PWM circuitry has a common control input coupled to one of the control outputs and wherein the common PWM driver current has a duty cycle selectable between 10% to 90%. ### Claim 9 (depends on 3) The stepper motor controller of claim 3, wherein the common PWM driver current has a fixed duty cycle. ### Claim 10 (depends on 3) The stepper motor controller of claim 3, wherein each of the individual PWM driver currents has a duty cycle selectable between 0% to 100%. ### Claim 11 A method for controlling a stepper motor that has a plurality of stepper motor field coils, a plurality of individual driver terminals, and a common driver terminal, the method being performed by a stepper motor controller that has a group of individual drivers and a common driver, wherein each individual driver has an individual driver output coupled to one of the plurality of individual driver terminals, and the common driver has a common driver output coupled to the common driver terminal, and wherein each of the field coils is connected between respective individual driver terminals and the common driver terminal, the method comprising: selectively providing individual pulse width modulated (PWM) driver currents provided by each individual driver at the respective individual driver terminals; and supplying a common PWM driver current provided by the common driver at the common driver terminal. ### Claim 12 (depends on 11) The method for controlling a stepper motor of claim 11, wherein the individual PWM driver currents flow from at least one of the individual driver outputs and into the common driver output. ### Claim 13 (depends on 12) The method for controlling a stepper motor of claim 12, wherein the common PWM driver current flows from the common driver output and into at least one of the individual driver outputs. ### Claim 14 (depends on 11) The method for controlling a stepper motor of claim 11, wherein at least two of the individual PWM driver currents have different duty cycles. ### Claim 15 (depends on 11) The method for controlling a stepper motor of claim 11, wherein each of the individual PWM driver currents has a duty cycle selectable between 0% to 100%. ### Claim 16 (depends on 11) The method for controlling a stepper motor of claim 11, wherein the common PWM driver current has a fixed duty cycle of 50%. ### Claim 17 (depends on 11) The method for controlling a stepper motor of claim 11, wherein the common PWM driver current has a duty cycle selectable between 10% to 90%. ### Claim 18 (depends on 11) The method for controlling a stepper motor of claim 11, wherein each individual driver and the common driver includes series connected complementary transistors coupled between power supply nodes. ### Claim 19 A stepper motor controller for controlling one or more stepper motors, the controller comprising: control circuitry having control outputs; a group of individual drivers, each individual driver in the group having an individual driver input coupled to a respective one of the control outputs and an individual driver output coupled to an individual driver terminal of the controller; common driver pulse width modulation (PWM) circuitry having a common driver PWM output; and a common driver having a common driver input coupled to the common driver PWM output and a common driver output coupled to a common driver terminal of the controller, wherein when one or more stepper motor field coils are connected between respective individual driver terminals and the common driver terminal, steady-state digital logic values are supplied to the stepper motor field coils from the individual driver terminals, and a PWM driver current is supplied to the stepper motor field coils from the common driver terminal. ### Claim 20 (depends on 19) The stepper motor controller of claim 19, wherein the common driver PWM circuitry has a common control input coupled to one of the control outputs, and wherein the common PWM driver current has a duty cycle selectable between 10% to 90%.