Chengdu Monolithic Power Systems Co., Ltd.

Monolithic Power Systems, Inc.

Ipgoal Microelectronics (sichuan) Co., Ltd.

Lei Li

Zhaolei Wu

Yike Li

Rui Wang

Changjiang Chen

Haishi Wang

A controller for a switching converter has a hysteresis generating circuit to provide an upper hysteresis limit and a lower hysteresis limit based on an output voltage, a switching control circuit for providing a switching control signal, and a frequency locking circuit for adjusting one of the upper hysteresis limit and the lower hysteresis limit based on the switching control signal and a clock signal. When the switching converter is in a first mode, a main switch of the switching converter is turned ON by comparing a current sense signal representative of a current flowing through the main switch with the lower hysteresis limit, and is turned OFF by comparing the current sense signal with the upper hysteresis limit. When the switching converter is in a second mode, the main switch is turned ON based on the clock signal, and is turned OFF based on the current sense signal.

Control circuit with hysteresis control for switching converters and control method thereof

A method for controlling an efuse circuit is provided. The method includes the following steps. A sample signal of a switch is provided. An error signal is generated according to the sample signal and a reference signal. The error signal is compared with a threshold. A voltage across a control node of the switch and an output node of the switch is clamped to a preset voltage value when the error signal is greater than the threshold.

Efuse circuit and control method thereof

A control circuit for controlling a switching converter having a low quiescent current. The control circuit has an error amplifying circuit, an on time generator, a first comparing circuit and a second comparing circuit. When the switching converter operates in a light load operation mode, the error amplifying circuit and the on time generator are deactivated. Meanwhile, the first comparing circuit compares a current sensing signal indicative of inductor current with a current reference signal to provide an off time control signal during an on state of a low side switch to determine an on moment of a high side switch. The second comparing circuit compares the voltage feedback signal with a voltage reference signal to provide an on time control signal to determine an off moment of the high side switch.

Switching converter with low quiescent current and control circuit thereof

A control circuit and control method for controlling a step-up switching converter. The control circuit has an ultra-low voltage regulation module used to generate a control signal based on an output voltage feedback signal and an input voltage signal. When the input voltage signal is smaller than an ultra-low voltage threshold, the control signal controls a high side switch of the step-up switching converter off and controls a low side switch of the step-up switching converter to perform on and off switching. Meanwhile, a parasitic diode of the high side switch is on once the low side switch is off.

Step-up switching converter and control circuit and method thereof

A switching regulator with improved load regulation is discussed. The switching regulator increases an on time length of a first power switch if the switching regulator operates at discontinuous current mode and a current flowing through the second power switch crosses a zero reference, until the first power switch is turned on again; and the switching regulator maintains the on time length of the first power switch during other time period.

Switching regulator with improved load regulation and the method thereof

A power converter including a load transient enhancing module and associated method for improving load transient response of the power converter. The load transient enhancing module detects whether load transient is occurring in a load of the power converter, and turns the secondary switch off and locks the secondary switch at 'OFF' state to turn on a body diode of the secondary switch once load transient is occurring in the load.

Power converter with improved load transient response and associated control method

A COT control circuit for DC-DC converter. The COT control circuit has a synchronizing signal generator, an on time generator and a frequency locking circuit. The synchronizing signal generator generates a synchronizing signal and a frequency-modulated signal. The on time generator receives an input voltage signal, an output voltage signal, an error signal and the frequency-modulated signal to generate an on time signal. The error signal is generated by the frequency locking circuit based on the on time signal and the synchronizing signal. The operation frequency of a steady state of the DC-DC converter is regulated through changing the value of the frequency-modulated signal.

COT control circuit and associated DC-DC converter

A driving circuit and method for buck-boost converter with bootstrap voltage refresh. The driving circuit includes a first bootstrap capacitor provided a first bootstrap voltage to drive the corresponding switch, and a second bootstrap capacitor provided a second bootstrap voltage to drive the corresponding switch. When converter operates in buck mode and the first or second bootstrap voltage is smaller than a threshold, the driving circuit generates current signals to respectively charge the first and second bootstrap capacitors based on an input voltage, and the first and second bootstrap voltages. When converter operates in boost mode and the first or second bootstrap voltage is smaller than the threshold, the driving circuit generates current signals to respectively charge the first and second bootstrap capacitors based on an output voltage, and the first and second bootstrap voltages.

Driving circuit and method for buck-boost converter with bootstrap voltage refresh

A current sensing circuit used in a buck-boost converter having a pair of buck switches and a pair of boost switches, including: a first sensing circuit providing a detection current though a first normally-ON transistor and a second normally-ON transistor, and a second sensing circuit detecting an average of the detection current and providing a current sensing signal in accordance with the average. During a turn ON time of a first low side switch of the pair of buck switches, the detection current represents a current flowing through the first low side switch, the current sensing signal represents an output current. During a turn ON time of the second low side switch of the pair of boost switches, the detection current represents a current flowing through the second low side switch, and the current sensing signal represents an input current.

Current sensing circuit and integrated circuit for four-switch buck-boost convertor

Noise-free control circuit and control method for controlling a switching converter to avoid generating audile noises. The noise-free control circuit has a timer used to set a noise-free frequency threshed. When the switching frequency of the switching converter is decreased to the noise-free frequency threshold, the switching frequency of the switching converter is limited to the noise-free frequency threshold. The noise-free frequency threshold is higher than a maximum audible frequency of an audio noise.

Non-audible control circuit for a buck converter in DCM mode

A clock circuit and control method thereof to avoid missing the clock signal generated by the clock circuit when the generated clock signal is synced with an external clock signal, wherein the clock circuit comprises a current compensation circuit and a current control circuit. The clock signal is generated by alternately charging and discharging a capacitor with a charging current based on a sync current and a compensating current when an external clock signal is detected. The compensating current is generated based on a frequency of the external clock signal, and the sync current is provided based on a phase difference between the generated clock signal by the clock circuit and the external clock signal.

Clock circuit and control method thereof

A switching power supply system includes a switching converter, to convert an input voltage into an output voltage and to generate a switching signal; a feedback circuit, to generate a feedback signal; an error amplifier to generate an error signal; a triangle signal generator to generate a triangle signal; a constant on time control circuit to receive error signal and the triangle signal, and to generate a constant on time control signal to control power switch; in the system. The triangle signal has a DC bias based on either a soft start signal or a second reference signal. The system could perform soft start function and meanwhile keep matching between the error signal and the triangle signal.

Soft start switching power supply system

A control method of a switching converter, wherein the switching converter has a main transistor and is configured to provide an output signal. The control method includes: generating a feedback signal indicative of the output signal of the switching converter; generating a clock signal to determine the switching frequency of the main transistor; generating a control signal to control the main transistor based on the clock signal and the feedback signal; and detecting whether the on-time of the main transistor is smaller than a time threshold based on the control signal. If the on-time of the main transistor is smaller than the time threshold, the frequency of the clock signal will be adjusted to regulate the on-time of the main transistor to be equal to the time threshold.

Switching converter with smart frequency generator and control method thereof

A control method used in a four-switch buck-boost converter includes: filtering the voltage at the first switching node and generating a first ramp signal; filtering the first ramp signal and generating a first average signal; filtering the voltage at the second switching node and generating a second ramp signal; filtering the second ramp signal and generating a second average signal; generating a set signal based on the first ramp signal, the first average signal, the second ramp signal, the second average signal, a reference signal, and a feedback signal indicative of the output voltage, so as to turn on the first and third transistors, and turn off the second and fourth transistors; turning off the first transistor and turning on the second transistor when the on-time of the first transistor reaches a first time threshold; and turning off the third transistor and turning on the fourth transistor when the on-time of the third transistor reaches a second time threshold.

Buck-boost converters with ramp compensation

A trans-conductance regulation circuit, a trans-conductance error amplifier module and a power converter. The trans-conductance regulation circuit provides a bias current at least partially based on an output voltage of the power converter. The bias current is sent to bias a trans-conductance operational amplifier in the trans-conductance error amplifier module so that a trans-conductance of the trans-conductance operational amplifier is direct proportional to the output voltage of the power converter. The power converter regulates the output voltage based on a negative feedback loop comprising the trans-conductance error amplifier module. The trans-conductance error amplifier module may help to maintain a band width of the negative feedback loop substantially stable and immune to variations in the output voltage.

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Chengdu, China

Lei Li