A stepper driver for a motor includes an H-bridge, a sense transistor coupled to the H-bridge, a voltage-to-current (VtoI) converter, and a sine digital-to-analog converter (DAC). The VtoI converter has a VtoI converter input and a VtoI converter output. The VtoI converter output is coupled to the sense transistor. The sine DAC has a sine DAC digital input, a reference input, and a sine DAC output. The sine DAC output is coupled to the VtoI converter input. The sine DAC includes an R-2R network, an offset control circuit coupled to the R-2R network, and a gain control circuit also coupled to the R-2R network.

A stepper driver for a motor includes an H-bridge, a sense transistor coupled to the H-bridge, a voltage-to-current (VtoI) converter, and a sine digital-to-analog converter (DAC). The VtoI converter has a VtoI converter input and a VtoI converter output. The VtoI converter output is coupled to the sense transistor. The sine DAC has a sine DAC digital input, a reference input, and a sine DAC output. The sine DAC output is coupled to the VtoI converter input. The sine DAC includes an R-2R network, an offset control circuit coupled to the R-2R network, and a gain control circuit also coupled to the R-2R network.

A stepper motor driver includes an H-bridge including first and second outputs. The H-bridge includes a low-side transistor coupled between the first output and a ground. A reference current circuit is configured to produce a reference current. The reference current circuit has a reference output. An averager circuit includes an input and output. The input of the averager circuit is coupled to the first output of the H-bridge. A comparator includes first and second comparator inputs. The first input of the comparator is coupled to the output of the average circuit and the second input of the comparator is coupled to the reference output.

A stepper motor driver includes an H-bridge including first and second outputs. The H-bridge includes a low-side transistor coupled between the first output and a ground. A reference current circuit is configured to produce a reference current. The reference current circuit has a reference output. An averager circuit includes an input and output. The input of the averager circuit is coupled to the first output of the H-bridge. A comparator includes first and second comparator inputs. The first input of the comparator is coupled to the output of the average circuit and the second input of the comparator is coupled to the reference output.

A stepper driver for a motor includes an H-bridge, a sense transistor coupled to the H-bridge, a voltage-to-current (Vtol) converter, and a sine digital-to-analog converter (DAC). The Vtol converter has a Vtol converter input and a Vtol converter output. The Vtol converter output is coupled to the sense transistor. The sine DAC has a sine DAC digital input, a reference input, and a sine DAC output. The sine DAC output is coupled to the Vtol converter input. The sine DAC includes an R-2R network, an offset control circuit coupled to the R-2R network, and a gain control circuit also coupled to the R-2R network.

A stepper driver for a motor includes an H-bridge, a sense transistor coupled to the H-bridge, a voltage-to-current (Vtol) converter, and a sine digital-to-analog converter (DAC). The Vtol converter has a Vtol converter input and a Vtol converter output. The Vtol converter output is coupled to the sense transistor. The sine DAC has a sine DAC digital input, a reference input, and a sine DAC output. The sine DAC output is coupled to the Vtol converter input. The sine DAC includes an R-2R network, an offset control circuit coupled to the R-2R network, and a gain control circuit also coupled to the R-2R network.

A motor control apparatus operable to control a motor includes a phase determiner for determining a rotational phase of a rotor of the motor, and a controller having a first control mode for controlling a driving current flowing through a winding of the motor based on a current of a predetermined magnitude, and a second control mode for controlling a driving current flowing through the winding so that a deviation between a command phase representing a target phase of the rotor and a rotational phase determined by the phase determiner is reduced. The controller executes the first control mode without executing the second control mode in a case of rotating the motor in a first direction, and executes the second control mode in a case of rotating the motor in a second direction which is a reverse direction to the first direction.

Provided is a display device for a vehicle that can rapidly execute preparation completion for display of vehicle information. The display device for a vehicle is provided with a processing unit, a display, and a rotational drive unit that can rotate a reflector on a prescribed axis. The processing unit includes an estimating unit that estimates planned start of the vehicle by a crew, and when the vehicle is planned to be started, the angle of rotation of the rotational drive unit moves from an initial angle corresponding to an initial position (position of point of origin) of the reflector to a first intermediate angle (first stopping position) between the initial angle and a final angle corresponding to the normal operating position of the reflector. After the vehicle has been actually started, the angle of rotation of the rotational drive unit moves to a final angle from the first intermediate angle.

Provided is a display device for a vehicle that can rapidly execute preparation completion for display of vehicle information. The display device for a vehicle is provided with a processing unit, a display, and a rotational drive unit that can rotate a reflector on a prescribed axis. The processing unit includes an estimating unit that estimates planned start of the vehicle by a crew, and when the vehicle is planned to be started, the angle of rotation of the rotational drive unit moves from an initial angle corresponding to an initial position (position of point of origin) of the reflector to a first intermediate angle (first stopping position) between the initial angle and a final angle corresponding to the normal operating position of the reflector. After the vehicle has been actually started, the angle of rotation of the rotational drive unit moves to a final angle from the first intermediate angle.

According to one embodiment, a controller of a stepping motor includes a table generating unit and a current controlling unit. The table generating unit generates a data table of a threshold by using values of induced voltage at frequencies of switching signal that changes a set value of a drive current, the threshold being proportional to a frequency of the switching signal within an operation region in which the frequency of the switching signal is lower than a predetermined frequency, the values of the induced voltage including a first induced voltage generated at a first frequency of the switching signal and a second induced voltage generated at a second frequency of the switching signal. The current controlling unit controls a value of the drive current in accordance with a comparison result between the threshold and an induced voltage that is detected at a frequency lower than the predetermined frequency.