Abstract: An example apparatus includes a level shifter having a first supply input, a gate driver having a second supply input coupled to the first supply input and adapted to be coupled to a cathode of a diode, the gate driver having an output adapted to be coupled to a control terminal of a switch, and a current source circuit having an input and an output, the input adapted to be coupled to a power supply and the output adapted to be coupled to the first supply input, the second supply input and to a capacitor.

Abstract: A system includes a level shifter coupled to a voltage source, a first transistor, and a second transistor. The system also includes a first current source coupled to the first transistor and the second transistor and configured to bias the first transistor and the second transistor. The system includes a slew detector coupled to the voltage source and to the first current source, where the slew detector is configured to detect a change in voltage of the voltage source, and further configured to provide current to the first current source responsive to detecting the change. The system also includes a second current source coupled in parallel to the first current source, where the second current source is configured to provide current to the first current source responsive to a control signal.

Abstract: A system includes a level shifter coupled to a voltage source, a first transistor, and a second transistor. The system also includes a first current source coupled to the first transistor and the second transistor and configured to bias the first transistor and the second transistor. The system includes a slew detector coupled to the voltage source and to the first current source, where the slew detector is configured to detect a change in voltage of the voltage source, and further configured to provide current to the first current source responsive to detecting the change. The system also includes a second current source coupled in parallel to the first current source, where the second current source is configured to provide current to the first current source responsive to a control signal.

Abstract: An example apparatus includes a level shifter having a first supply input, a gate driver having a second supply input coupled to the first supply input and adapted to be coupled to a cathode of a diode, the gate driver having an output adapted to be coupled to a control terminal of a switch, and a current source circuit having an input and an output, the input adapted to be coupled to a power supply and the output adapted to be coupled to the first supply input, the second supply input and to a capacitor.

Abstract: Enhanced motor power control circuitry is presented herein. In one implementation, a circuit includes power transistor elements in a half-bridge arrangement configured to selectively switch current for a phase of a motor according to control signals applied to corresponding gate terminals. The circuit also includes control circuitry configured to produce the control signals to achieve target states among the power transistor elements. The control signals have ramp rates determined based at least on polarities of the current through the power transistor elements during inactive states.

Abstract: A transistor, e.g., field effect transistor FET, ringing adjustment circuit and method comprising the measuring of a voltage from a transistor (e.g., a node of a FET) during the transistor turning on and turning off, determining the voltage oscillation in the measured voltage by performing a derivative function on the measured voltage and detecting a switch in a voltage change rate from positive to negative or negative to positive, and comparing the voltage change rate after the detected switch to adjust drive current applied to the transistor to optimize efficiency while minimizing voltage oscillation and ringing.

Abstract: Enhanced motor power control circuitry is presented herein. In one implementation, a circuit includes power transistor elements in a half-bridge arrangement configured to selectively switch current for a phase of a motor according to control signals applied to corresponding gate terminals. The circuit also includes control circuitry configured to produce the control signals to achieve target states among the power transistor elements. The control signals have ramp rates determined based at least on polarities of the current through the power transistor elements during inactive states.

Abstract: Enhanced motor power control circuitry is presented herein. In one implementation, a circuit includes power transistor elements in a half-bridge arrangement configured to selectively switch current for a phase of a motor according to control signals applied to corresponding gate terminals. The circuit also includes control circuitry configured to produce the control signals to achieve target states among the power transistor elements. The control signals have ramp rates determined based at least on polarities of the current through the power transistor elements during inactive states.

Abstract: An electronic circuit includes a first switch driver, a second switch driver, and a switch node coupled to the first and second switch drivers, and configured to couple to a motor. The electronic circuit also includes slew rate measurement circuitry coupled to the switch node and configured to measure a slew rate of switching operations at the switch node. The electronic circuit also includes a controller coupled to the first switch driver, to the second switch driver, and to the slew rate measurement circuitry, and configured to compare a measured slew rate provided by the slew rate measurement circuitry with a target slew rate, and to selectively adjust control signals to at least one of the first and second switch drivers based on a comparison result. The first and second switch drivers are configured to drive switches to power the motor based on the control signals.

Abstract: Enhanced motor power control circuitry is presented herein. In one implementation, a circuit includes power transistor elements in a half-bridge arrangement configured to selectively switch current for a phase of a motor according to control signals applied to corresponding gate terminals. The circuit also includes control circuitry configured to produce the control signals to achieve target states among the power transistor elements. The control signals have ramp rates determined based at least on polarities of the current through the power transistor elements during inactive states.

Abstract: A transistor, e.g., field effect transistor FET, ringing adjustment circuit and method comprising the measuring of a voltage from a transistor (e.g., a node of a FET) during the transistor turning on and turning off, determining the voltage oscillation in the measured voltage by performing a derivative function on the measured voltage and detecting a switch in a voltage change rate from positive to negative or negative to positive, and comparing the voltage change rate after the detected switch to adjust drive current applied to the transistor to optimize efficiency while minimizing voltage oscillation and ringing.

Abstract: An electronic circuit includes a first switch driver, a second switch driver, and a switch node coupled to the first and second switch drivers, and configured to couple to a motor. The electronic circuit also includes slew rate measurement circuitry coupled to the switch node and configured to measure a slew rate of switching operations at the switch node. The electronic circuit also includes a controller coupled to the first switch driver, to the second switch driver, and to the slew rate measurement circuitry, and configured to compare a measured slew rate provided by the slew rate measurement circuitry with a target slew rate, and to selectively adjust control signals to at least one of the first and second switch drivers based on a comparison result. The first and second switch drivers are configured to drive switches to power the motor based on the control signals.

Abstract: Reducing noise for an amplifier-based system circuit that comprises a first differential input pair and a second differential input pair, a first input stage circuit connected to the first differential input pair, wherein the first input stage is configured with a first transconductance value, a second input stage circuit connected to the second differential input pair, wherein the second input stage is configured with a second transconductance value that is less than the first transconductance value, a transimpedance circuit coupled to the first input stage circuit and the second input stage circuit, and a feedback loop circuit coupled to the transimpedance circuit and to the second differential input pair, wherein the feedback loop circuit is not connected to the first differential input pair.

Abstract: A system comprises a buffer circuit coupled to a comparator, and an adaptive threshold control circuit coupled to a timer and comparator. Buffer circuit receives a first voltage across a control terminal and a first current terminal of a transistor and a second voltage across a second current terminal and the first current terminal of the transistor. Comparator compares first voltage to a first threshold, generating a first trigger signal when it crosses first threshold, and compares second voltage to a second threshold, generating a second trigger signal when it crosses second threshold. Timer determines length of time between trigger signals. Adaptive threshold control circuit generates a first control signal for first trigger signal, and a second control signal for second trigger signal, and provides a control signal to comparator indicative of whether length of time is greater than or less than user-programmed value, causing comparator to adjust first threshold.

Abstract: Reducing noise for an amplifier-based system circuit that comprises a first differential input pair and a second differential input pair, a first input stage circuit connected to the first differential input pair, wherein the first input stage is configured with a first transconductance value, a second input stage circuit connected to the second differential input pair, wherein the second input stage is configured with a second transconductance value that is less than the first transconductance value, a transimpedance circuit coupled to the first input stage circuit and the second input stage circuit, and a feedback loop circuit coupled to the transimpedance circuit and to the second differential input pair, wherein the feedback loop circuit is not connected to the first differential input pair.

Abstract: A method for verifying an operation of a Hall-effect sensor without an applied magnetic field. The method can include providing a bias signal to a first pair of terminals of a Hall-effect element, applying a Hall current signal to a second pair of terminals of the Hall-effect element, measuring a Hall output voltage across the second pair of terminals and comparing the measured Hall output voltage to an expected Hall output voltage that would be provided by a corresponding applied magnetic field.

Abstract: Stepper motor winding current regulation methods and apparatus continuously and bi-directionally sense winding current to determine both the magnitude of the winding current and the slope of a waveform representing the winding current. The magnitude and slope information is used to more precisely control periods of current rise and characteristics of fast and slow current decay during pulse-width modulation (“PWM”) regulation cycles. Winding current rise and decay shaping is based upon the sensed magnitude of the winding current, the magnitude of the winding current regulation set-point ITRIP, whether the sensed winding current is greater than or less than ITRIP at a selected sampling time, whether the sensed winding current is increasing or decreasing when a waveform of the sensed winding current crosses over ITRIP, and whether or not the magnitude of ITRIP changes during a PWM cycle in response to a receipt of a subsequent DAC code.

Abstract: A method for verifying an operation of a Hall-effect sensor without an applied magnetic field. The method can include providing a bias signal to a first pair of terminals of a Hall-effect element, applying a Hall current signal to a second pair of terminals of the Hall-effect element, measuring a Hall output voltage across the second pair of terminals and comparing the measured Hall output voltage to an expected Hall output voltage that would be provided by a corresponding applied magnetic field.

Abstract: Stepper motor winding current regulation methods and apparatus continuously and bi-directionally sense winding current to determine both the magnitude of the winding current and the slope of a waveform representing the winding current. The magnitude and slope information is used to more precisely control periods of current rise and characteristics of fast and slow current decay during pulse-width modulation (“PWM”) regulation cycles. Winding current rise and decay shaping is based upon the sensed magnitude of the winding current, the magnitude of the winding current regulation set-point ITRIP, whether the sensed winding current is greater than or less than ITRIP at a selected sampling time, whether the sensed winding current is increasing or decreasing when a waveform of the sensed winding current crosses over ITRIP, and whether or not the magnitude of ITRIP changes during a PWM cycle in response to a receipt of a subsequent DAC code.