Abstract: A motor driving circuit for driving a direct-current (DC) motor, includes a driving circuit for converting an input voltage into a first and a second output voltages, a Hall sensor for generating a first and a second time sequential control signals according to a working condition of the DC motor, a current sensing unit for comparing the motor current to a reference current to generate a comparison result, and a control unit coupled to the driving circuit, the current sensing unit and the Hall sensor for controlling a working status of the driving circuit according to the first and the second time sequential control signals and the comparison result.

Abstract: A modulation method, for a voltage converting device, includes generating a first modulation signal according to an input voltage and a first output voltage; generating a second modulation signal according to the input voltage and a second output voltage; adjusting the first modulation signal and the second modulation signal according to a clock signal for making a first starting time of the first modulation signal be different from a second starting time of the second modulation signal; and generating the first output voltage and the second output voltage according to the input voltage, the first modulation signal and the second modulation signal.

Abstract: A charging current setting method for a charging module includes detecting at least two voltage values associated with two input current values of an input voltage signal at an input terminal of the charging module to calculate an input resistance; setting a lower limit voltage value of the input voltage signal according to the input resistance; controlling an input current to increase its magnitude, so that voltage level of the input voltage signal decreases in accordance with increasing level of the input current; controlling the input voltage signal to remain on the lower limit voltage value when the input voltage signal is decreasing and reaches the lower limit voltage value, and recording a magnitude of the input current as an upper limit current value when the input voltage signal is on the lower limit voltage value and the input current becomes stable; and determining a charging current value of the charging module according to the upper limit current value.

Abstract: A zero current detecting circuit is disclosed. The zero current detecting circuit includes a first zero current comparator for determining current variation on an inductor of a synchronous switching power converter so as to output a zero current signal to turn off a down-bridge transistor of the synchronous power converter; a second zero current comparator for determining whether the first zero current comparator turns off the down-bridge transistor too early or too late and outputting a comparison result; a counter coupled to the second zero current comparator for ascending or descending a control bit according to the comparison result, and an adjustable delay unit coupled to the first zero current comparator and the counter for adjusting a delay time according to the control bit, and delaying and outputting the zero current signal according to the delay time, to compensate a negative offset voltage by delay.

Abstract: An audible noise avoiding circuit and a DC-DC boost converter for a DC-DC boost converter are provided. The audible noise avoiding circuit comprises a timing controller and a linear regulator. The timing controller discharges a timing capacitor to a low voltage according to switching of the DC-DC boost converter. A sink output stage of the liner regulator is coupled to the output voltage node. When the voltage of the timing capacitor is higher than a threshold voltage, the compensation unit compensates the output of the operational amplifier for gradually turning on the sink output stage in order to gradually reduce the voltage of the output voltage node. A predetermined charging time interval is defined by the time interval of charging the timing capacitor from the low voltage to the threshold voltage, the reciprocal of the predetermined time interval is a frequency in the ultrasonic wave frequency range.

Abstract: A rotation speed control circuit with function of auto-calibrating rotation speed error is disclosed. The rotation speed control circuit includes a first multiplexer, a second multiplexer, an error amplifier and a current compensation circuit. In calibration mode, the rotation speed control circuit selects a calibration clock signal and a calibration voltage through the first multiplexer and the second multiplexer correspondingly according to a mode switch signal, and adjusts current value of a first current accordingly. In other words, the rotation speed control circuit utilizes the first current to compensate error of the external capacitor through the calibration clock signal fixed and the calibration voltage fixed in the duration of calibration mode, so as to avoid that aging of the external capacitor leads to rotation speed error and then affects the whole operation.

Abstract: The present invention discloses a bootstrap DC-DC converter. The bootstrap DC-DC converter includes a lower gate driver, for generating a lower gate control signal according to a control signal; a lower gate, for turning on and turning off according to a lower gate control signal; and a bootstrap voltage maintaining circuit, for generating the control signal, such that the lower gate turns on at least a minimum off time each time.

Abstract: A voltage conversion circuit is disclosed. The voltage conversion circuit comprises an energy-storing inductor, an N-type transistor, a P-type transistor, a current comparator, a multiplexer, a first driver and a second driver. When load connected to the voltage conversion circuit is a light load, the P-type transistor will be switched off so as to avoid generating a switching current and the switching current flowing gate-source and gate-drain parasitic capacitor of the N-type transistor is generated from an input voltage. The number of N-type transistor and switching frequency also decrease accordingly so that voltage conversion efficiency of the voltage conversion circuit may be increased.

Abstract: An over voltage protection circuit comprises an input end, coupled to an input power, for receiving an input voltage provided by the input power; and a driving module, coupled between the input end and a ground end, for generating a discharging current when the input voltage is larger than a predefined voltage, to reduce the input voltage to the predefined voltage. The driving module comprises a voltage regulating module, a p-channel metal-oxide-semiconductor field-effect transistor (PMOS), and an n-channel metal-oxide-semiconductor field-effect transistor (NMOS). The PMOS and the NMOS are an upper gate switch and a lower gate switch of a motor driver or a fan driver.

Abstract: A control module of constant on-time mode for a voltage converting device, includes a comparing unit, for generating a comparing signal according to an enhanced feedback voltage and a comparing voltage; a feedback voltage generating unit, for generating the enhanced feedback voltage according to a voltage difference between a first reference voltage and a feedback voltage corresponding to an output voltage of the voltage converting device; a comparing voltage generating unit, for generating the comparing voltage according to a second reference voltage and a control signal; and a adjusting unit, for acquiring an average voltage of the enhanced feedback voltage and adjusting the first reference voltage according to a voltage difference between the average voltage and the second reference voltage.

Abstract: A voltage converting device includes a feedback module, for generating a comparing signal according to a feedback voltage and a reference voltage; a pulse-width-modulation module, for generating a driving signal according to comparing signal; a voltage-converting module including a low-side switch for controlling a connection between a node and ground according to driving signal, a high-side switch for controlling a connection between the node and an output end according to a control signal, an inductor coupled between the node and an input end, a feedback-voltage-generating unit for generating feedback voltage according to an output voltage of output end and a ratio, an adaptive current-generating unit for generating a current signal according to an adjusting signal, and a control unit for selecting driving signal or current signal as the control signal according to output voltage and an input voltage; and a current-adjusting module for generating adjusting signal according to comparing signal.

Abstract: A voltage detection circuit comprises a reference resistor including a terminal for receiving a first voltage; a reference transistor including a control terminal for receiving a second voltage; a comparator, including a first input terminal for receiving a converted voltage and a second input terminal for receiving the second voltage, for generating an output voltage; and a voltage dropping circuit series, comprising a plurality of voltage dropping circuits connected in a series, for converting an input voltage into the converted voltage; wherein the comparator indicates whether the input voltage matches a specific multiple of a voltage difference between the first voltage and the second voltage, and the specific multiple relates to a number of the plurality of voltage dropping circuits.

Abstract: An output-stage circuit is disclosed. The output-stage circuit includes high-side output driver, first body selector, low-side output driver, second body selector and inductance. When output current is larger than current threshold value so as to make the low-side output driver generate overcurrent, the low-side output driver controlled by second control signal is disabled, and the high-side output driver controlled by first control signal is enabled so as to create first current channel. When output current is larger than current threshold value so as to make the high-side output driver generate overcurrent, the high-side output driver controlled by the first control signal is disabled, and the low-side output driver controlled by the second control signal is enabled so as to create second current channel to avoid current flowing through low-side output driver's body, and thus reduce the output current and voltage spiking of the output voltage.

Abstract: A power management system coupled to a speaker module includes a monitor module for measuring a current signal and a voltage signal of the speaker module to obtain a real-time impedance information of the speaker module; a reception module for receiving a time-domain audio analogy signal to be transformed into a frequency-domain audio digital signal; a prediction module for generating a power prediction information according to an initial audio information, the real-time impedance information and the audio digital signal; a control module for generating a control signal according to the audio digital signal and a human hearing model information; and a power adjustment module for outputting an adjustment audio signal to the speaker module according to the power prediction information, the audio digital signal and the control signal, so as to perform a broadcast operation of the speaker module.

Abstract: A motor driving circuit for driving a motor includes: a driving-stage circuit, for converting an input voltage into a first output voltage and a second output voltage, and comprising a first transistor, a second transistor, a third transistor and a fourth transistor; an output stage circuit, for converting the first output voltage or the second output voltage into a motor speed signal; and a control unit, coupled to the first, the second, the third and the fourth transistors and the output stage circuit, for generating first, second, third and fourth transistor control signals to control the first, the second, the third and the fourth transistors respectively.

Abstract: A current-mode buck converter is disclosed, wherein the current-mode buck converter operates in a pulse width modulation (PWM) mode or a pulse frequency modulation (PFM) mode. When the current-mode buck converter enters into the PFM mode, the voltage level of the parking voltage is maintained at the voltage level of compensation voltage, so as to decrease switch loss of the current-mode buck converter operating between PWM mode and PFM mode, and stabilize the output voltage of the current-mode buck converter.

Abstract: A current mode DC-DC conversion device with fast transient response is provided. The device includes a DC-DC converter, a pulse width control unit, a current feedback circuit, a fast transient feedback circuit, a first error amplifier, an adder, and a comparator. The current feedback circuit generates a current feedback signal according to the current passing through an inductor in the DC-DC converter. The fast transient feedback circuit generates a transient feedback signal according to a first voltage feedback signal. The first error amplifier amplifies the difference value between a second voltage feedback signal and a reference signal to generate an error amplification signal. The comparator compares the error amplification signal and the summation of current feedback signal and transient feedback signal to generate a comparison signal. The comparison signal is provided to the pulse width control unit for controlling the duty cycle of the power switch.

Abstract: A voltage converting device includes a feedback module, for generating a comparing signal according to a feedback voltage and a reference voltage; a pulse-width-modulation module, for generating a driving signal according to comparing signal; a voltage-converting module including a low-side switch for controlling a connection between a node and ground according to driving signal, a high-side switch for controlling a connection between the node and an output end according to a control signal, an inductor coupled between the node and an input end, a feedback-voltage-generating unit for generating feedback voltage according to an output voltage of output end and a ratio, an adaptive current-generating unit for generating a current signal according to an adjusting signal, and a control unit for selecting driving signal or current signal as the control signal according to output voltage and an input voltage; and a current-adjusting module for generating adjusting signal according to comparing signal.

Abstract: A power management system coupled to a speaker module includes a monitor module for measuring a current signal and a voltage signal of the speaker module to obtain a real-time impedance information of the speaker module; a reception module for receiving a time-domain audio analogy signal to be transformed into a frequency-domain audio digital signal; a prediction module for generating a power prediction information according to an initial audio information, the real-time impedance information and the audio digital signal; a control module for generating a control signal according to the audio digital signal and a human hearing model information; and a power adjustment module for outputting an adjustment audio signal to the speaker module according to the power prediction information, the audio digital signal and the control signal, so as to perform a broadcast operation of the speaker module.

Abstract: A signal-phase DC motor control circuit is disclosed. The signal-phase DC motor control circuit includes a logic circuit, a switching circuit and a driving circuit. The logic circuit transmits a first logic signal, a second logic signal, a third logic signal and a forth logic signal. The switching circuit transmits a first direction driving signal according to a PWM signal and the first logic signal, and transmits a second direction driving signal according to the PWM signal and the second logic signal. The driving circuit transmits a first output signal according to the first direction driving signal and the fourth logic signal, and transmits a second output signal according to the second direction driving signal and the third logic signal. The first output signal and the second output signal are positive half-wave sinusoidal wave, and the phase difference between the first output signal and the second output signal is 180 degrees.