Abstract: A power failure prevention system includes a switch circuit, an energy storage circuit, a voltage detector circuit and a control circuit. The switch circuit includes a first switch, a second switch, a third switch and a fourth switch. The energy storage circuit is connected to the switch circuit. The voltage detector circuit detects an input voltage provided by an input voltage source and a stored voltage of the energy storage circuit. The control circuit controls the switch circuit according to the detected input voltage and stored voltage. When the input voltage is higher than a first threshold, the switch circuit allows the input voltage to charge the energy storage circuit. When the input voltage is lower than a second threshold, the switch circuit allows the stored voltage to discharge to the input voltage source. The first threshold is higher than the second threshold.

Abstract: An electrostatic discharge protection circuit includes an internal circuit, a pad, a first high voltage transistor, an electrostatic protection element and a control circuit. A first terminal of the first high voltage transistor is coupled to the pad, a second terminal of the first high voltage transistor is coupled to the internal circuit and includes a control terminal. The electrostatic protection element has one end coupled to the first end of the first high voltage transistor and the other end grounded. The control circuit is coupled between the control terminal of the first high voltage transistor and the ground terminal. The control circuit is configured to control the first high voltage transistor to turn off when the pad receives an electrostatic voltage.

Abstract: A light sensing device is provided, which includes a photodiode, a capacitor circuit and an ADC. The ADC includes a comparator, a counter, a reset switch, a logic circuit and a reference voltage switching circuit. The reference voltage switching circuit is controlled by the logic circuit to a determination reference voltage. When a primary integration time ends, a first node has a residual voltage that does not reach a reference voltage, the logic circuit controls the reference voltage switching circuit to provide the determination reference voltage to the comparator or the capacitor circuit within a secondary integration time, and the comparator outputs a comparison signal, the logic circuit receives the comparison signal within the secondary integration time, and determines the secondary value and outputs to the counter. The counter generates a primary value within the primary integration time, and the primary value is combined with the secondary value.

Abstract: A light sensor having an adaptively controlled gain includes a photoelectric element, an operational amplifier, a comparator, an adaptive gain control circuit, a variable capacitor and a pulse accumulator circuit. The photoelectric element converts light energy into a photocurrent. The operational amplifier outputs an error amplified signal based on a gain multiplied by a voltage difference between an input voltage and a reference voltage. The comparator compares the error amplified signal with a voltage of a reference voltage source to output a comparison signal. The adaptive gain control circuit includes a pulse detector circuit and a gain control circuit. The pulse detector circuit detects the comparison signal and a clock signal to output a pulse detected signal. The adaptive gain control circuit outputs a capacitance modulating signal according to the pulse detected signal. A capacitance of the variable capacitor is modulated according to the capacitance modulating signal.

Abstract: A motor driving circuit for a single phase motor and a motor driving method for the same are provided. The motor driving circuit includes a motor driver, a Hall sensor, a Hall commutation detection circuit, a period recording circuit, a motor current detection circuit, a cut-off angle adjustment circuit, an angle calculation circuit and a control circuit. The motor current detection circuit detects a motor current value at a commutation point after the single phase motor operates normally. The cut-off angle adjustment circuit generates a cut-off angle adjustment signal indicating a cut-off adjustment angle according to the motor current value when the single phase motor passes the commutation point. The control circuit processes the commutation signal and the cut-off signal generated by the angle calculation circuit to generate a control signal group to control the motor driver to generate an output signal group to drive the motor.

Abstract: An inductor current detecting circuit is provided. A differentiator circuit differentiates a high-side voltage signal to generate a first differential signal, and differentiates a low-side voltage signal to generate a second differential signal. A first current source outputs a first charging current according to the first differential signal. A second current source outputs a second charging current according to the second differential signal. First and second terminals of a first switch are respectively connected to the first current source and a first terminal of a second switch. A second terminal of the second switch is connected to the second current source. Two terminals of a capacitor are connected to the second terminal of the first switch and the second current source respectively. The first switch and the second switch are alternately turned on to obtain a continuous waveform.

Abstract: An optical sensor and a method having a high linearity digital controlling mechanism are provided. An optoelectronic component converts a light energy into a photocurrent. Then, the photocurrent flows to a current mirror and is amplified by a gain to form a charging current by the current mirror to charge a capacitor. A comparator compares a voltage of the capacitor with a reference voltage multiple times to generate a comparison signal. A counter determines a digital value capturing range according to the gain, and counts bit values that fall within the digital value capturing range from the comparison signal to output a counted signal. A noise cancellation processor reduces the digital value capturing range according to the gain, and removes one or more of the bit values that do not fall within the digital value capturing range from the counted signal to output a sensed signal.

Abstract: A power converter is provided. A driver circuit is connected between a controller circuit and a switch circuit. The switch circuit is connected to an inductor. The inductor is connected in series with a first capacitor and grounded through the first capacitor. A first comparison input terminal of a first comparator is connected to an output terminal between the inductor and the first capacitor. A second comparison input terminal of the first comparator is grounded through a second capacitor. The controller circuit outputs a control signal for controlling the driver circuit to drive the switch circuit according to a comparison signal outputted by the first comparator. A reference current source provides a reference current to the second capacitor. A first terminal of a first resistor is connected to the second capacitor. A second terminal of the first resistor is coupled to a reference potential.

Abstract: A power failure prevention system and method with a power management mechanism are provided. A switch circuit is connected to a first terminal of an inductor. An energy storage circuit is connected to the switch circuit. A pre-charged circuit is connected to an input power source and a second terminal of the inductor. A pre-charging control circuit is connected to the pre-charged circuit and configured to obtain a voltage of a node between the pre-charged circuit and the second terminal of the inductor, a voltage of the switch circuit or a voltage of the energy storage circuit as a pre-charged voltage. The input power source pre-charges the pre-charged circuit. When the pre-charging control circuit determines that the pre-charged voltage is higher than or equal to a reference voltage, the pre-charging control circuit controls the pre-charged circuit, allowing the input power source to charge the energy storage circuit.

Abstract: A motor driving circuit and a motor driving method are provided. The motor driving circuit is used to drive a motor, and includes a starting unit, a driving unit, a floating phase selecting unit, a hysteresis comparator, an integration circuit, a first comparator and a control circuit. The control circuit controls the floating phase selecting unit to select a floating phase to output a floating phase voltage signal, and controls, in response to an initial starting signal, the integration circuit to use a first integration time, and determine whether the motor has been successfully started. In response to a successful start, the control circuit controls the integration circuit to use a second integration time, and controls the starting unit to be switched to an operation mode to control the driving unit to drive the motor. The first integration time is greater than the second integration time.

Abstract: A current detecting circuit of a constant on-time power converter and a method thereof are provided. The current detecting circuit includes a time detecting circuit and a sample and hold circuit. A control circuit of the constant on-time power converter outputs a lower bridge conduction signal to turn on a lower bridge switch during an on-time of each cycle of the lower bridge conduction signal. The time detecting circuit detects the on-time of a cycle of the lower bridge conduction signal. The sample and hold circuit samples and holds a current of an inductor at a detection time point of a next cycle of the lower bridge conduction signal. A time between a rising edge of a waveform of the next cycle of the lower bridge conduction signal and the detection time point is equal to half the on-time.

Abstract: An analog-to-digital converting system and a method with offset correction mechanisms are provided. The method includes steps of: obtaining a direct current offset of an output voltage of a digital analog conversion unit in a system; obtaining first capacitance weights and second capacitance weights sequentially from small to large; subtracting the direct current offset from a digital signal; and multiplying bit values of the digital signal respectively by the corresponding first capacitance weight value or second capacitance weight value to output a decode signal.

Abstract: An adaptive frequency adjusting system is provided. An error amplifier outputs an error amplified signal according to an output voltage of a power converter and a reference voltage. When a comparator determines that a voltage of a slope signal reaches a voltage of the error amplified signal within a maximum on-time of an upper bridge switch, the comparator outputs a reset signal. When the comparator determines that the voltage of the slope signal fails to reach the voltage of the error amplified signal and the maximum on-time ends, the comparator outputs the reset signal and instructs a clock generator to output a clock signal having a lower frequency. A driver circuit turns off the upper bridge switch and turns on a lower bridge switch according to the reset signal, and drives the upper bridge switch based on the clock signal having the lower frequency.

Abstract: A synchronous power converter system is provided. The system includes a processor circuit and a plurality of power converters. The processor circuit outputs a plurality of clock signals having the same frequency. The power converters respectively receive the clock signals. Each of the power converters includes an oscillator circuit, a frequency detector circuit, a compensator circuit, a controller circuit, and a switch circuit. The oscillator circuit outputs an oscillation signal. The frequency detector circuit receives the clock signal and the oscillation signal and detects a clock frequency of the clock signal and an oscillation frequency of the oscillation signal to output a frequency detected signal. The compensator circuit outputs a compensating signal according to the frequency detected signal. The controller circuit controls the switch circuit according to the compensating signal.

Abstract: A light sensor with high linearity is provided. A photoelectric component converts light energy into a photocurrent to a first capacitor. An error amplifier has a first amplification input terminal and a second amplification input terminal, which are respectively connected to a reference voltage source and a first terminal of a first transistor. A first terminal of a second transistor is connected to the second amplification input terminal. A second terminal of the first transistor is connected to the first capacitor. An output terminal of the error amplifier is connected to a second terminal of the second transistor. A first comparator compares a voltage of the first capacitor with a lowest one of a modulated voltage and a reference voltage to generate a first comparing signal. A counter circuit performs counting according to the first comparing signal.

Abstract: A charger having a fast transient response and a control method thereof are provided, which decide how to quickly respond to a requirement of a load by determining whether an input current reference signal indicating an input current is larger than or equal to a maximum safe current of a transformer. Therefore, the charger and the control method realize the fast transient response without having to control switching between a boost circuit and a buck circuit. Meanwhile, the charger and the control method thereof can be prevented from being damaged by an excessive input current and can stabilize an output voltage of the load more quickly.

Abstract: A motor driving device having a lock protection mode includes a rotation speed detecting unit, an operating unit, a driving unit, a floating point selecting unit, a BEMF detecting unit, a control unit, and a lock protection unit. The operating unit enters an operating mode after a motor is stably operated, and generates an operating signal having phases according to a commutation sequence, and the driving unit drives the motor. The BEMF detecting unit detects a BEMF of a first floating phase to generate a detection result. The control unit outputs a commutation signal to cause the driving unit to drive the motor. When the rotation speed detecting unit determines that a rotation speed of the motor exceeds a predetermined rotation speed, the rotation speed detecting unit outputs a switching signal to the lock protection unit to enter the lock protection mode.

Abstract: A motor driving device includes a first hysteresis comparator, a second hysteresis comparator, a logic circuit, a control unit, and an inverter circuit. The logic circuit receives a start signal or a start completion signal to output the first output signal as a commutation signal according to the start signal, or to output the second output signal as the commutation signal according to the start completion signal, clamps the second output signal by the first output signal, stops outputting the commutation signal after the potential state of the commutation signal is changed, and unclamps the second output signal with the first output signal and outputs the commutation signal in response to a difference voltage between the first input signal and the second input signal being greater than a positive value of the first hysteresis voltage or less than a negative value of the first hysteresis voltage.

Abstract: A rapid sensing value estimation circuit and a method thereof are provided. The rapid sensing value estimation 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, and an arithmetic module. The clock generator generates a clock signal. The second counter counts the clock signal 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 estimates the first count value at an end of an integration time according to a ratio of the second maximum count value to the second count value and the first count value when the second count value exceeding the first predetermined count value, to generate an estimated count value result.

Abstract: A dynamical time gain controlling light sensing device generates a detection time configuration signal according to a light intensity indication signal, and generates a set of adjustment switch signals to respectively control the plurality of gain selection switches to be turned on or off according to a ratio of a real gain time and a simulation gain time within a detection time, such that an overall gain of a resolution adjustment circuit can correspond to an substitute gain lower than a set gain within the simulation gain time and correspond to the set gain within the real gain time, thereby generating an adjusted count result signal.