Abstract: For applying a driving voltage to a motor, an H-bridge circuit is constructed by a first and a second linear unit and a first and a second switching unit. An error amplifier generates an error signal representative of a difference between the driving voltage detected by a voltage detecting circuit and a command voltage signal. A state control circuit synchronously controls the first and second switching units and a feedback circuit. Through the feedback circuit, the error signal is selectively applied to the first or second linear unit such that one is operated in a linear mode and the other is operated in a nonconductive mode, thereby controlling the driving voltage to become proportional to the command voltage signal. The state control circuit further controls a brake circuit for transforming the error signal into a brake signal to operate the first and second linear units simultaneously in a conductive mode.

Abstract: A Hall sensing circuit generates a positional detection signal representative of a positional relationship between a rotor and a phase coil of a motor. A signal synthesizing circuit transforms the positional detection signal to a driving signal. Based on a comparison of the driving signal and a high-frequency reference signal, a pulse signal is generated for controlling a switching circuit to drive the motor. A current error signal is supplied through feedback to adjust a relative relationship between an amplitude of the drive signal and an amplitude of the high-frequency reference signal, thereby changing a duty ratio of the pulse signal. A duty-ratio limiting circuit is provided to limit the duty ratio of the pulse signal for ensuring a reliable rotation of the motor.

Abstract: A Hall sensing circuit generates a positional detection signal representative of a positional relationship between a rotor and a phase coil of a motor. A signal synthesizing circuit transforms the positional detection signal to a driving signal. Based on a comparison of the driving signal and a high-frequency reference signal, a pulse signal is generated for controlling a switching circuit to drive the motor. A current error signal is supplied through feedback to adjust a relative relationship between an amplitude of the drive signal and an amplitude of the high-frequency reference signal, thereby changing a duty ratio of the pulse signal. A duty-ratio limiting circuit is provided to limit the duty ratio of the pulse signal for ensuring a reliable rotation of the motor.

Abstract: For applying a driving voltage to a motor, an H-bridge circuit is constructed by a first and a second linear unit and a first and a second switching unit. An error amplifier generates an error signal representative of a difference between the driving voltage detected by a voltage detecting circuit and a command voltage signal. A state control circuit synchronously controls the first and second switching units and a feedback circuit. Through the feedback circuit, the error signal is selectively applied to the first or second linear unit such that one is operated in a linear mode and the other is operated in a nonconductive mode, thereby controlling the driving voltage to become proportional to the command voltage signal. The state control circuit further controls a brake circuit for transforming the error signal into a brake signal to operate the first and second linear units simultaneously in a conductive mode.

Abstract: For applying a driving current to a motor, an H-bridge circuit is constructed by a first and a second switching unit and a first and a second linear unit. An error amplifier generates an error signal representative of a difference between the driving current detected by a current detecting circuit and a command current signal. A state control circuit synchronously controls the first and second switching units and a feedback circuit. Through the feedback circuit, the error signal is selectively applied to the first or second linear unit such that one is operated in a linear mode and the other is operated in a nonconductive mode, thereby controlling the driving current to become proportional to the command current signal. The state control circuit further controls a brake circuit for transforming the error signal into a brake signal to operate the first and second linear units simultaneously in a conductive mode.

Abstract: For applying a driving current to a motor, an H-bridge circuit is constructed by a first and a second switching unit and a first and a second linear unit. An error amplifier generates an error signal representative of a difference between the driving current detected by a current detecting circuit and a command current signal. A state control circuit synchronously controls the first and second switching units and a feedback circuit. Through the feedback circuit, the error signal is selectively applied to the first or second linear unit such that one is operated in a linear mode and the other is operated in a nonconductive mode, thereby controlling the driving current to become proportional to the command current signal. The state control circuit further controls a brake circuit for transforming the error signal into a brake signal to operate the first and second linear units simultaneously in a conductive mode.

Abstract: A Hall sensing circuit generates a positional detection signal representative of a positional relationship between a rotor and a phase coil of a motor. A signal synthesizing circuit transforms the positional detection signal to a driving signal. Based on a comparison of the driving signal and a high-frequency reference signal, a pulse signal is generated for controlling a switching circuit to dive the motor. A current error signal is supplied through feedback to adjust a relative relationship between an amplitude of the drive signal and an amplitude of the high-frequency reference signal, thereby changing a duty ratio of the pulse signal. A duty-ratio limiting circuit is provided to limit the duty ratio of the pulse signal for ensuring a reliable rotation of the motor.

Abstract: A switching DC-to-DC converter includes multiple power supply channels, coupled in parallel between a DC voltage source and ground, for converting the DC voltage source into multiple DC output voltages that are separate from each other. An oscillator outputs multiple oscillating signals to render each of the multiple power supply channels make at least one switching transition differently in the time domain from others of the multiple power supply channels, thereby improving transient noise. The multiple oscillating signals include two triangular wave signals with a phase difference of 180 degrees and two pulse wave signals with a-phase difference of 180 degrees. Rising edges of the two pulse wave signals occur simultaneously with either a peak or a valley of the two triangular wave signals, respectively.

Abstract: A switching DC-to-DC converter includes multiple power supply channels, coupled in parallel between a DC voltage source and ground, for converting the DC voltage source into multiple DC output voltages that are separate from each other. An oscillator outputs multiple oscillating signals to render each of the multiple power supply channels make at least one switching transition differently in the time domain from others of the multiple power supply channels, thereby improving transient noise. The multiple oscillating signals include two triangular wave signals with a phase difference of 180 degrees and two pulse wave signals with a phase difference of 180 degrees. Rising edges of the two pulse wave signals occur simultaneously with either a peak or a valley of the two triangular wave signals, respectively.

Abstract: A first oscillating signal presenting a peak, a valley, a rising portion gradually increasing from the valley to the peak, and a falling portion gradually decreasing from the peak to the valley is generated. A second oscillating signal presenting an instantly transiting edge, which occurs simultaneously with either the peak or the valley of the first oscillating signal, is generated. The first and the second oscillating signals are input to a first and a second power supply channels, respectively, for converting a DC voltage source into two separate DC output voltages. The first and the second oscillating signals cause at least one switching transition of the first power supply channel to occur separately in the time domain from at least one switching transition of the second power supply channel, thereby preventing transient spikes from superposing together.