Abstract: A motor control circuit is disclosed, which uses one hall sensor to sense the position of the magnetic poles of three-phase motor, and to execute phase switching mechanism by start controller and operation controller. The motor control circuit drives the three-phase motor from a start state to a normal operation state. In the start state, the start controller controls the switching time and controls storage to transmit the digital models of the phase switching to the operation controller. The operation controller executes the phase switching of the full-bridge circuit according to the received digital models, to drive the three-phase motor. In the normal operation state, the start controller stops transmitting the digital models of the phase switching to the operation controller. The operation controller captures six digital models in sequence once every switching time, and executes the phase switching of the full-bridge circuit, to drive the three-phase motor.

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: Disclosed are a shutdown method for motor and a motor driving circuit using the same. The method comprises: shutting down a higher gate switch and a lower gate switch when a supply voltage decreases, such that the storage capacitor is charged via a back electromotive force, wherein the back electromotive force decreases as the motor gradually stops; driving the motor when the voltage of the storage capacitor is again larger than the first threshold voltage; determining whether the voltage of the storage capacitor is lower than a shutdown threshold voltage when the voltage of the storage capacitor is lower than the first threshold voltage, wherein the shutdown threshold voltage is lower than the first threshold voltage; and turning on the lower gate switch when the voltage of the first threshold voltage is lower than the shutdown threshold voltage, wherein the back current is related to the back electromotive force.

Abstract: Disclosed is an operation method for LED dimming device. The operation method includes the following steps. Step A: sampling a pulse width modulation signal, and respectively counting for a time period when the pulse width modulation signal is at high level and a time period when the pulse width modulation signal is at low level. Step B: determining whether a rising edge of the pulse width modulation signal is detected. Step C: calculating a duty cycle of the pulse width modulation signal when the rising edge is detected. Step D: resetting a counter module. Step E: driving a LED module according to the duty cycle.

Abstract: The present disclosure illustrates a single-inductor dual-output (SIDO) power converter for hysteresis current control mode and a control method thereof. In the SIDO power converter provided by the instant disclosure, a detecting circuit, connected to the upper bridge transistor, determines whether the inductive current reaches the upper limit threshold or the lower limit threshold, and further drives a control circuit to turn on or off the corresponding upper bridge transistor and/or the lower bridge transistor, so as to simplify the operation of the hysteresis current control mode.

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: The present disclosure illustrates a motor speed curve control circuit. The motor speed curve control circuit is configured for adjusting a speed of a motor according to a motor speed curve. The motor speed curve control circuit comprises a divider resistor module, an analog-to-digital converter and an arithmetic unit. The resistor module is configured for generating at least one turning-point voltage. The turning-point voltage is used to adjust a slope of the motor speed curve. The analog-to-digital converter converts the turning-point voltage to digital form. The arithmetic unit sets a speed associated with the turning-point voltage corresponding to a first preset duty cycle in the motor speed curve, such that the motor speed curve becomes linear. The arithmetic unit generates a second pulse width modulation signal according to the adjusted motor speed curve and a first pulse width modulation signal to drive the motor.

Abstract: The present disclosure illustrates a motor drive circuit. The motor drive circuit includes a resistor module, a multiplexer, a data control unit, an analog-to-digital converter and a register. The resistor module receives an input voltage and generates at least one parameter voltage. The parameter voltage is associated with a motor speed curve of a motor. The multiplexer receives the parameter voltage. The data control unit controls the multiplexer to output the parameter voltage. The analog-to-digital converter receives the parameter voltage and converts the parameter voltage to digital form, and then outputs the digital parameter voltage to the data control unit. The register stores the digital parameter voltage outputted by the data control unit. A controller determines the motor speed curve according to the digital parameter voltage stored in the register, and drives the motor in response to the motor speed curve.

Abstract: A motor driving circuit is provided, which selects a Hall sensor or a Sensor-less controller to achieve the phase commutation of a magnetic pole of a motor through a hall positive terminal and a hall negative terminal of a hall control device. When the hall positive terminal and the hall negative terminal receive a first hall signal and a second hall signal generated by the Hall sensor, the motor driving circuit selects the Hall sensor and then accordingly drives the motor. When the hall positive terminal and the hall negative terminal are floating, or one of them receives a high-voltage, the motor driving circuit selects the sensor-less controller and then accordingly drives the motor. Accordingly, the motor driving circuit can select different sensing devices to achieve the phase commutation of the magnetic pole of the motor according to the motor characteristics.

Abstract: A buck-boost converter and a control circuit thereof are disclosed. When an input voltage is close to an output voltage (i.e., the buck-boost converter operates in a buck-boost mode), the control circuit of the buck-boost converter generates specific switching signals. Four switches of a switching regulator are switched by the switching signals, so that the four switches are not turned-on or turned-off frequently because of the input voltage closing to the output voltage. Accordingly, the buck-boost converter and the control circuit thereof of the disclosure can reduce switch noise of the four switches and switching loss of the whole circuit, to improve conversion efficiency of the buck-boost converter.

Abstract: The present disclosure illustrates a current balance method and a current balance circuit thereof. The current balance method is used in a multiphase digital pulse width modulator. Steps of the current balance method are as follows. A plurality of pulse width values of the pulse width modulated signals within a first period are recorded, and a minimum pulse width value is defined as a standard value. The method determines whether each pulse width value is larger than the sum of the standard value and a pulse width threshold, and if yes, the method adds 1 to a count value of the phase output stage corresponding to the pulse width value. The method determines whether each count value equals to a counting threshold, and if yes, the method adjusts the pulse width modulated signal, and initializing the count value as 0.

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: A motor driving circuit with power reversal protection and a fan device are disclosed. The motor driving circuit has a supply end and a ground end. A reversal protection circuit is configured in the motor driving circuit and is electrically connected to the supply end. When a power line and a ground line of a power supply electrically and respectively connect to the supply end and the ground end (indicating a correct connection condition), the reversal protection circuit is turned on, so that the motor driving circuit receives the power transmitted from the power supply to operate. When the power line and the ground line of the power supply electrically and respectively connect to the ground end and the supply end (indicating an incorrect connection condition), the reversal protection circuit is turned off, so that the motor driving circuit does not receive the power transmitted from the power supply.

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: The present disclosure provides a positive and negative rotation control circuit and fan system, which can positively or negatively rotate a fan motor according to an end connecting to different external components or being floating. When the end generates an oscillatory fan signal, the positive and negative rotation control circuit negatively rotates the fan motor for a period of time after the positive and negative rotation control circuit is started for a delay time, to execute the operation of exhausting the accumulated dust, so that a fan connecting to the fan motor may exhaust the accumulated dust from an electronic device. Then the control circuit positively rotates the fan motor to execute the operation of dissipating heat, so that the fan may dissipate heat in the situation of having less dust within the electronic device. Accordingly, the heat dissipation effect of the fan may be enhanced.

Abstract: A multi-phase boost converter with phase self-detection and a detecting circuit thereof are provided. The multi-phase boost converter comprises M switching circuits, a capacitor, a control circuit and a detecting circuit. Each switching circuit has an input end and an output end. N inductors are coupled in parallel between the input ends and an input voltage. The output ends are coupled to an output voltage. The control circuit controls the conduction status of the switching circuits according to a feedback voltage corresponding to the output voltage. The detecting circuit coupled between the input ends and the control circuit detects the conduction status between the input voltage and each of the input ends, for outputting a first control signal. The control circuit controlled by the first control signal selectively controls at least one of the switching circuits. N is a positive integer less than or equal to M.

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.