Anpec Electronics Corporation

Chun-Kai Hsu

Chih-Heng Su

Chih-Ning Chen

Chih-Yuan Chen

Kun-Yi Lin

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 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 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 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 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.

Charger having fast transient response and control method thereof

Disclosed are a non-narrow voltage direct current (NON-NVDC) charger and a control method thereof. In the present disclosure, a proper target voltage, related to a turn-on voltage of a switch circuit, is determined according to an output voltage of a load, a storage voltage of an energy storage device and a turn-on resistance value of the switch circuit. Then, according to the determined target voltage, the NON-NVDC charger can enter a supplement mode at an appropriate time. The NON-NVDC charger can be operated stably and has excellent operation efficiency even when a current flowing through a transformer close to a maximum safe current.

Non-narrow voltage direct current charger and control method thereof

An abnormal power failure control system and a method thereof are provided. The system includes a first comparator, a boost-buck control circuit, a logic control circuit, a switch circuit, a current sensor circuit, a current slope comparator circuit, a second comparator, and a mode switching circuit. The first comparator compares a stored power with a first reference voltage source to output a first voltage compared signal. The boost-buck control circuit outputs a boost-buck control signal and the logic control circuit accordingly controls the switch circuit. The current slope comparator circuit determines change of a slope of a current of the switch circuit. The second comparator compares the stored power with the second reference voltage to output a second voltage compared signal. The mode switching circuit instructs the logic control circuit to control the switch circuit.

Abnormal power failure control system and method

The present disclosure provides a self-adaptive startup compensation device. The self-adaptive startup compensation device provides an operational transconductance amplifier that outputs a bias current to the error amplifier of the negative feedback loop of the DC-to-DC converter in such a manner that the error amplifier adjusts the error amplifier signal to be outputted, thereby adjusting the compensation signal generated by the negative feedback loop during a startup period.

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Hsinchu, Taiwan

Chun-Kai Hsu