Abstract: A brake control system of a motor is provided. When a control circuit intends to brake the motor, the control circuit controls a driver circuit to turn off a first high-side switch and a second high-side switch, and to fully turn on the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off one of the first low-side switch and the second low-side switch, and to continually turn on the other one of the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off the other one of the first low-side switch and the second low-side switch, and to turn on the one of the first low-side switch and the second low-side switch, for a period of time.

Abstract: A power converter for providing a negative voltage is provided. A coupling controller circuit receives a digital control signal and provides a control signal. A reverse voltage converter circuit receives the control signal and provides a reverse voltage. The reverse voltage converter circuit includes a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a seventh switch, an eighth switch, a coupling control signal triggering circuit and a pulse width modulation circuit. A first reverse logic circuit is connected to a second reverse logic circuit. The second reverse logic circuit is connected to the pulse width modulation circuit and is configured to provide a trigger signal to the pulse width modulation circuit. The pulse width modulation circuit turns on or off the reverse voltage converter circuit according to the trigger signal.

Abstract: A power converter having a slew rate controlling mechanism is provided. A first terminal of a high-side switch is coupled to an input voltage. A first terminal of a low-side switch is connected to a second terminal of the high-side switch. A second terminal of a first capacitor is connected to a node between the second terminal of the high-side switch and the first terminal of the low-side switch. A first terminal of an inductor is connected to the second terminal of the first capacitor and to the node. A first terminal of a second capacitor is connected to a second terminal of the inductor. A second terminal of the second capacitor is grounded. An input terminal of a current controlling device is connected to a power output terminal of a high-side buffer. An output terminal of the current controlling device is connected to the node.

Abstract: A current limit protecting system and method of a motor pre-driver are provided. A current limiting circuit detects a current of a resistor that is connected to a motor, and then compares the current of the resistor with a current threshold to output a current comparing signal. When a controller circuit determines that the current of the resistor is larger than the current threshold according to the current comparing signal, and a working period of a first signal of a first node or a working period of a second signal of a second node of the motor reaches a preset value, a first high-side switch and a second high-side switch are turned off, and a first low-side switch and a second low-side switch are alternately turned on. As a result, a temperature of the motor generally reduces.

Abstract: A sensor is provided. A first terminal of a first current source and a first terminal of a first transistor are connected to a cathode of the photodiode. A control terminal of a second transistor is connected to an output terminal of a first operational amplifier. A first terminal of the second transistor is connected to a second terminal of the first transistor through a first current mirror circuit. A second terminal of the second transistor is connected to a second current source, a second input terminal of a second operational amplifier and a first terminal of a third transistor. A first input terminal of the second operational amplifier is connected to the first terminal of the first transistor. A control terminal of the third transistor is connected to an output terminal of the second operational amplifier.

Abstract: A system and a method for automatically correcting a rotational speed of a motor of a fan are provided. After the fan is moved from an open space to a closed space, a sample and hold circuit samples and holds working periods of a driving signal by which the motor is driven to rotate at a first rotational speed as a first sampled working period, and a working period of a driving signal by which the motor is driven to rotate at a second rotational speed. An arithmetic circuit calculates a difference between the first sampled working period and a first reference working period, and a difference between the second sampled working period and a second reference working period. The arithmetic circuit calculates other working periods of driving signals by which the motor is driven to rotate at other rotational speeds based on the differences.

Abstract: A rapid sensing value estimation circuit and a method thereof are provided. The circuit includes a first sensing unit, an integration sensing circuit and a rapid estimation circuit. The rapid estimation circuit includes a clock generator, a second counter, a first digital comparator, an arithmetic module and a remainder calculation module. The clock generator generates a clock signal with a first frequency. The second counter counts the clock signal within the integration time to generate a second count value. The first digital comparator determines whether the second count value exceeds a first predetermined count value when the first count value increases. The arithmetic module calculates an estimated count value result and a remainder, and the remainder calculation module can further calculate and estimate values of decimal places of this signal based on the remainder.

Abstract: A motor current controlling circuit having a voltage detection mechanism is provided. A first terminal of a first low-side transistor is connected to a second terminal of a first high-side transistor. A node between the first terminal of the first low-side transistor and the second terminal of the first high-side transistor is connected to a first terminal of a motor. A first terminal of a second low-side transistor is connected to a second terminal of a second high-side transistor. A zero current detector circuit detects a voltage of the node and determines whether or not a current flowing through the motor is equal to a zero value to output a zero current detected signal according to the detected voltage. A controller circuit controls a driver circuit to turn on or off the high-side transistors and the low-side transistors according to the zero current detected signal.

Abstract: A signal gain determination circuit including a digital comparator, a digital controller and an arithmetic module, and a signal gain determination method are provided. A sensing integration circuit generates a first count during a first integration time according to a first sensing signal. The digital comparator compares the first count and a predetermined count to generate a comparison result. The digital controller generates a control signal for indicating a signal gain to a signal amplifier of the sensing integration circuit according to the comparison result. The signal amplifier adjusts the first sensing signal according to the signal gain to generate a second sensing signal, so that the sensing integration circuit generates a second count corresponding to the second sensing signal during a second integration time. The arithmetic module generates an output count corresponding to the first sensing signal according to the second count and the signal gain.

Abstract: A motor protecting circuit is provided. A first terminal of each of high-side transistors is coupled to a power supply voltage. A second terminal of each of low-side transistors is grounded. Second terminals of the high-side transistors are respectively connected to first terminals of the low-side transistors. An overvoltage detector circuit is coupled to the power supply voltage of an output circuit. When the overvoltage detector circuit determines that the power supply voltage of the output circuit is higher than a voltage threshold, the overvoltage detector circuit outputs an overvoltage detected signal to a controller circuit. According to the overvoltage detected signal, the controller circuit controls a driver circuit to turn on at least one of the high-side transistors and at least one of the low-side transistors at the same time.

Abstract: A power converter with a negative current detection mechanism is provided. A negative current detecting circuit includes a first operational amplifier, a first transistor and a second transistor. A non-inverting input terminal of the first operational amplifier is connected to a second terminal of a sense resistor. An inverting input terminal of the first operational amplifier is connected to a first terminal of a first capacitor. Control terminals of the first and second transistors are connected to an output terminal of the first operational amplifier. A first terminal of the first transistor is connected to the second terminal of the sense resistor. A second terminal of the first transistor is grounded. A first terminal of the second transistor is connected to the inverting input terminal of the first operational amplifier and the first terminal of the first transistor. A second terminal of the second transistor is grounded.

Abstract: An electromagnetic interference reducing circuit is provided. A first random number generator generates a plurality of first random number signals each having a plurality of triangular waves. Each of the triangular waves has a plurality of steps. The first random number generator generates a plurality of first random numbers and modulates each of the first random number signals according to the first random numbers. The first random number generator repeatedly counts, repeatedly removes, or does not count time of the steps of each of the triangular waves of each of the first random number signals according to one of the first random numbers. A first oscillator generates a first oscillating signal. A motor controller circuit controls a plurality of switch components of a motor respectively according to the first random number signals based on the first oscillating signal.

Abstract: A circuit measuring device and a method thereof are provided. A voltage source supplies a common voltage such that a calibration current having a preset current value flows from a current-voltage converter to a final test machine. The current-voltage converter converts the calibration current into a calibration voltage. At this time, a voltage sensing component senses a voltage between an input terminal and an output terminal of the current-voltage converter to output sensed calibration data. The current-voltage converter converts a tested current outputted by a tested circuit into a tested voltage. At this time, the voltage sensing component senses the voltage between the input terminal and the output terminal of the current-voltage converter to output actual sensed data. When the final test machine determines that a difference between the sensed calibration data and the actual sensed data is larger than a threshold, the tested circuit is adjusted.

Abstract: A three-phase motor driving circuit and a three-phase motor driving method are provided. The three-phase motor driving circuit includes an inverter circuit, a control circuit, a turn-off module, a turn-off confirmation module, and a turn-on logic unit. The inverter circuit includes a plurality of phase circuits, each including an upper bridge switch and a lower bridge switch. The control circuit operates in a feedback mode to output a feedback start signal. The turn-off module includes a feedback detection unit, a voltage adjusting unit, and a turn-off logic unit. The feedback detection unit detects an output current of a designated phase circuit, and if the output current flows out, a voltage regulation signal is output until the output current is 0, and a lower bridge turn-off signal is output. The voltage adjusting unit adjusts the voltage of the output node to be close to a predetermined voltage.

Abstract: A transient response improving system and method with a prediction mechanism of an error amplified signal are provided. A current sensor circuit senses a current flowing through a first resistor connected between an adapter and an electronic device. When the current is larger than a current threshold, a predicting circuit calculates a target voltage level based on a common voltage and a voltage of the battery and instantly pulls up or down a voltage level of the error amplified signal to the target voltage level. A comparator compares the error amplified signal with a ramp signal to output a comparison signal. A controller circuit controls a driver circuit to switch a high-side switch and a low-side switch according to the comparison signal.

Abstract: A counter is provided. A charge distributing circuit includes a first switch, a second switch, a third switch, a fourth switch, a third capacitor and a fourth capacitor. A first terminal of the first switch and a first terminal of the third switch are connected to a first input terminal of an operational amplifier. A second terminal of the first switch is connected to a first terminal of the third capacitor and a first terminal of the fourth switch. A second terminal of the third switch is connected to a first terminal of the fourth capacitor and a first terminal of the second switch. A second terminal of the third capacitor and a second terminal of the fourth capacitor are grounded. A second terminal of the second switch and a second terminal of the fourth switch are coupled to a reference voltage.

Abstract: A method of adjusting brightness of a display device is provided. The method includes steps of: generating a synchronization signal having a plurality of periods each of which is a frame time; determining bit values of dithering data according to target brightness data; and determining how many pulse waves in the pulse wave width modulation signal need to be modulated within the frame time according to the bit values of the dithering data, and accordingly modulating widths of the pulse waves of the pulse wave width modulation signal.

Abstract: A dual-slope optical sensor is provided. Two terminals of a first charging switch are respectively connected to an optoelectronic component and a first terminal of a capacitor. Two terminals of a second charging switch are respectively connected to a second terminal of the capacitor and grounded. First terminals of third charging and discharging switches are respectively connected to the first and second terminals of the capacitor. First terminals of fourth charging and discharging switches are respectively coupled to first and second reference voltages. Two terminals of a first discharging switch are respectively connected to the optoelectronic component and the second terminal of the capacitor. A first input terminal of a comparator is connected to second terminals of the third charging switch and the fourth discharging switch. A second input terminal of the comparator is connected to second terminals of the fourth charging switch and the third discharging switch.

Abstract: A driver circuit of a capacitive speaker is provided. Positive and negative power terminals of a first output stage circuit are respectively coupled to a first power source and a second power source. The first output stage circuit outputs a first voltage signal to a first terminal of a capacitive load of the capacitive speaker according to a first audio input signal, a voltage of the first power source and a voltage of the second power source. Positive and negative power terminals of a second output stage circuit are respectively coupled to the second power source and a third power source. The second output stage circuit outputs a second voltage signal to a second terminal of the capacitive load of the capacitive speaker according to a second audio input signal, a voltage of the second power source and a voltage of the third power source.

Abstract: A system of driving and controlling a motor is provided. A main controller adjusts frequencies of all or some of pulse waves of an initial pulse width modulation signal to output a pulse width modulation signal according to instruction information. The adjusted frequency of each of the pulse waves is equal to a first preset frequency or a second preset frequency. When a motor driver drives the motor to stably rotate, the motor driver decodes each of the pulse waves having the first preset frequency into a first message and decodes each of the pulse waves having the second preset frequency into a second message. The motor driver arranges and combines all of the first messages and the second messages that are decoded from the pulse waves to obtain the instruction information. The motor driver executes an operation instructed by the instruction information.