Anpec Electronics Corporation

Chih-Heng Su

Chun-Kai Hsu

Chih-Ning Chen

Chih-Yuan Chen

Yi-chuan Lu

Ke-Horng Chen

Yu-Huei Lee

Jia-Hua Hong

Hung-Wen Lu

Yueh-Lung Kuo

Yi-Ping Su

Hung-Chun Yeh

Ciou-Fong Li

Yu-Ping Huang

Sheng-Wen Pan

Yang-Fan Su

A buck converter using an ultra-low working current is provided. An error amplifier amplifies a difference between a voltage of an output terminal of the buck converter and a reference voltage to output an error amplified signal. A comparator compares a voltage of the error amplified signal with a ramp voltage to output a comparison signal. A control circuit controls a driver circuit to drive a high-side switch and a low-side switch according to the comparison signal. When the buck converter does not enter an ultra-low current mode, a low current controller circuit controls a system circuit to obtain an input current from an input power source. When the buck converter enters the ultra-low current mode, the low current controller circuit controls the system circuit to stop obtaining the input current from the input power source.

Buck converter using ultra-low working current

A power converter improving input overvoltage from output voltage drop is provided. The power converter includes a high-side switch, a low-side switch, a control circuit, a voltage threshold determining circuit and a voltage drop suppression circuit. The voltage threshold determining circuit determines whether or not an output voltage of the power converter is dropping to determine or adjust a voltage threshold. The voltage drop suppression circuit detects a voltage of a first terminal of the high-side switch. When the voltage drop suppression circuit determines that the detected voltage of the first terminal of the high-side switch is higher than the voltage threshold, the voltage drop suppression circuit pulls down the voltage of the first terminal of the high-side switch.

Power converter improving input overvoltage from output voltage drop

A switching charger for accurately sensing a small current is provided. First terminals of first transistors and a second transistor are coupled to a system voltage. Second terminals of the first transistors and a first input terminal of an operational amplifier are connected to a battery. A first terminal of a third transistor is connected to a second terminal of the second transistor and a second input terminal of the operational amplifier. A control terminal of the third transistor is connected to an output terminal of the operational amplifier. A first terminal of a fourth transistor is connected to a second terminal of the third transistor. First terminals of fifth transistors are coupled to an input voltage. Control terminals of the first transistors and the fifth transistors are connected to a control circuit. First terminals of sixth transistors are respectively connected to second terminals of the fifth transistors.

Switching charger capable of accurately sensing small current

A switching charger for supplying stable power is provided. First input terminals of first and fourth operational amplifiers and a second input terminal of a second operational amplifier are connected to a battery. A second input terminal of the first operational amplifier is coupled to a reference voltage. A first input terminal of the second operational amplifier and a second input terminal of the fourth operational amplifier are connected to an inductor. A first input terminal of a third operational amplifier is connected to an input power source. A second input terminal of the third operational amplifier is connected to a system circuit. A first selector circuit is connected to output terminals of the third and fourth operational amplifiers. A second selector circuit is connected to output terminals of the first and second operational amplifiers and the first selector circuit.

Switching charger for supplying stable power

A power converter with adaptively adjustable voltages based on detected currents is provided. A current detector circuit detects values of currents flowing through a plurality of switch components multiple times. Each time when all of the detected values of the currents flowing through the plurality of switch components are normal current values, a counter counts down a reference voltage to decrease the reference voltage. When the detected value of the current flowing through any one of the plurality of switch components is an abnormal current value, the counter counts up the reference voltage to increase the reference voltage. A controller circuit controls a high-side switch and a low-side switch to operate according to the reference voltage received from the counter each time.

Power converter with adaptively adjustable voltages based on detected currents

An open-loop inductor current emulating circuit is provided. A current sensor circuit senses a current flowing through a first terminal of a low-side switch to output a current sensed signal. An emulation controller circuit outputs a plurality of charging current signals according to currents of a plurality of rising waveforms of the current sensed signal. The emulation controller circuit outputs a plurality of discharging current signals according to currents of a plurality of falling waveforms of the current sensed signal. A charging and discharging circuit generates a plurality of charging currents according to the charging current signals, and generates a plurality of discharging currents according to the discharging current signals. The charging and discharging circuit alternatively outputs the charging currents and the discharging currents to the capacitor to charge and discharge the capacitor multiple times, thereby achieving a purpose of emulating an inductor current.

Open-loop inductor current emulating circuit

A method of stabilizing data of digital signals is provided. The method includes steps of: setting a boundary coefficient; reading a piece of digital data; defining a value of the piece of digital data as a center value; outputting the value of the piece of digital data; reading a next piece of digital data; subtracting a value of the next piece of digital data from the previously outputted value to obtain a positive difference or a negative difference; and determining whether or not an absolute value of the positive or negative difference is larger than the boundary coefficient, if not, outputting the center value, if yes, updating the center value such that the updated center value is equal to the value of the next piece of digital data, and outputting the updated center value.

Method of stabilizing data of digital signals

A foreign object detecting system and a method are provided. A control circuit controls a light transmitter and a light receiver. The light transmitter is disposed adjacent to a detected object and emits a light signal toward the detected object. The light receiver is disposed adjacent to the detected object in a path along which the light signal reflected by the detected object travels. The light receiver receives the light signal reflected to the light receiver. In a pre-operation, the control circuit defines the light signal received by the light receiver when the foreign object is not on the detected object as a first reflected light signal. In a detection operation, the control circuit determines that a difference exists between the light signal currently received by the light receiver and the first reflected light signal, the control circuit determines that the foreign object is on the detected object.

Foreign object detecting system and method

A closed-loop inductor current emulating circuit is provided. An emulation controller circuit generates an emulating signal according to a current flowing through a first terminal of a low-side switch of a power converter. When the emulation controller circuit outputs the emulating signal to a charging and discharging circuit, the charging and discharging circuit outputs a charging and discharging signal to a first terminal of a capacitor according to the emulating signal. When the emulation controller circuit outputs the emulating signal to a control terminal of the capacitor to adjust a capacitance of the capacitor, the charging and discharging circuit outputs a charging and discharging signal to the first terminal of the capacitor according to one or both of an input voltage and an output voltage of the power converter.

Closed-loop inductor current emulating circuit

A power saving system of a battery charger is provided. A control terminal of a first transistor receives a wake-up signal. A counter is connected to a first terminal of the first transistor. The counter determines whether or not a working period of the wake-up signal from the first transistor is larger than a time threshold to output a counting signal. When the counting signal indicates that the working period of the wake-up signal is not larger than the time threshold, the counter and electronic components of an electronic device are turned off, thereby saving power of a battery. When the counting signal indicates that the working period of the wake-up signal is larger than the time threshold, the electronic device is switched from a power saving mode to a normal operation mode. In the normal operation mode, the battery can supply power to the electronic device.

Power saving system of battery charger

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.

Transient response improving system and method with prediction mechanism of error amplified signal

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.

Power failure prevention system with power management mechanism and power failure prevention method with power management mechanism

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.

Adaptive frequency adjusting system

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.

Dynamic time gain controlling light sensing device comprising a dynamic time gain adjustment module to control a plurality of gain selection switches

A charging device and a control method thereof are provided. The charging device includes an adapter, an energy storage unit and a charging module. The adapter provides an adapter current. The charging module receives the adapter current and provides a first charging current to charge the energy storage unit, or an output current to charge an electronic device. When the input current is larger than a first preset current and the first charging current is equal to or less than a third preset current, the charging module operates in a boost mode, such that the energy storage unit provides a second charging current to the charging module. When the second charging current is larger than the third preset current, the charging module enters a buck mode such that the energy storage unit is charged by the first charging current.

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Hsinchu, Taiwan

Chih-Heng Su