11 results about "Subharmonic oscillation" patented technology

The invention discloses a charge control method and circuit applied to a resonant conversion circuit, and electronic equipment. The charge control method comprises the following steps: acquiring an input voltage and an output voltage of the resonant conversion circuit; an adjustment output signal is obtained by using an error signal between the output voltage and the benchmark reference voltage; acquiring the amplitude change rate of the input voltage; obtaining a slope compensation slope by using the amplitude change rate; performing slope compensation on the adjustment output signal by adopting the slope compensation slope to obtain a feedback adjustment signal; generating a driving control signal by using the feedback regulation signal; and the driving control signal is sent to the resonant conversion circuit to adjust the on-off state of the resonant conversion circuit so as to adjust the output voltage. Through the above mode, the charge control method provided by the invention effectively improves the dynamic performance, avoids subharmonic oscillation under extreme conditions, dynamically adjusts the slope compensation slope in real time, and further ensures the stability in a relatively wide input voltage range.

The invention relates to a W-band low-noise voltage-controlled oscillator based on a transformer resonant cavity and harmonic extraction. The W-band low-noise voltage-controlled oscillator comprises a dual-core in-phase coupled oscillator core, a two-bit switched capacitor bank, a linear variable capacitor bank and an output buffer, the dual-core in-phase coupled oscillator core comprises a transformer resonant cavity and a harmonic extraction network, a fundamental wave oscillation signal is generated in the transformer resonant cavity and is coupled and output to the output buffer, and a high-power second harmonic oscillation signal is generated in the harmonic extraction network and is output as a target oscillation signal; the two-bit switched capacitor bank adopts an HBT switch with excellent high-frequency performance, the tuning range of the oscillator is divided into four sub-bands, and the tuning gain is reduced; the capacitance value of the linearized variable capacitor bank is linearly changed along with the tuning voltage height, and a conversion mechanism of flicker noise is inhibited; and the output buffer realizes load isolation and buffering of the fundamental wave oscillation signal. The voltage-controlled oscillator has low tuning gain and high output power in the W wave band, and excellent phase noise is achieved.

The application discloses a single-sensor digital control method of a three-level flying capacitor step-down converter, and comprises the following steps: analyzing the working mechanism of the three-level flying capacitor step-down converter circuit, including the on-off logic of each switching device during normal operation of the circuit, four static working modes and two dynamic working switching modes; taking a static working mode point (1, 0) as an example to analyze the influence of flying capacitor voltage balance on the normal operation of the circuit; aiming at the flying capacitor voltage balance problem of the three-level flying capacitor step-down converter circuit, a single-sensor digital control strategy is provided; an improved digital control strategy is provided; then, stability analysis is carried out on the algorithm; aiming at the digital control algorithm with subharmonic oscillation, a solution strategy is provided, a digital slope compensation technology is introduced, and the subharmonic oscillation problem existing in the algorithm is eliminated; based on the deduction of the digital valley voltage control technology, the digital peak voltage control technology is summarized and extended.

This invention discloses a constant current control method for a primary-side feedback flyback converter, relating to the field of isolated converter technology. The method includes: when the primary-side feedback flyback converter operates in continuous current mode, determining the transformer demagnetization duration, cycle duration, and primary winding current valley value for the nth switching control cycle; obtaining the switching turn-off duration for the (n+1)th switching control cycle based on the transformer demagnetization duration, cycle duration, primary winding current valley value, a set reference primary current peak value, and the desired target current value; controlling the switching turn-on duration for the (n+1)th switching control cycle based on the reference primary current peak value, and controlling the switching turn-off duration for the (n+1)th switching control cycle to be the calculated turn-off duration. This method avoids low-frequency current ripple by eliminating the need for PID modulation calculations and can eliminate subharmonic oscillations at low input voltages.

The application discloses a foldback type slope compensation system and a compensation method thereof, which adopts real-time sampling of the change of the conduction time of adjacent periods to correct the effect of slope compensation in real time, dynamically changes the size of the slope compensation voltage, enters a foldback type adjustment stage when the slope compensation is effective, and adopts a foldback method to find the optimal compensation amount, so that the problem of overlarge or too small slope compensation voltage can be effectively avoided, real-time disturbance caused by different input voltages and output voltages can be adjusted in real time, dynamic response is improved, and output voltage fluctuation caused by subharmonic oscillation can be effectively converged when the input voltage is low and the output is full.

This application relates to the field of analog integrated circuit design and discloses an adaptive ramp compensation circuit system applied to buck-boost circuits. The system mainly includes a current sensor and a ramp signal generator. The current sensor mirrors the current of the pull-up power transistor to the pull-up mirror transistor at a specific ratio, converting it into a voltage signal through a sensing resistor. The ramp signal generator reduces the influence of the input voltage on the ramp signal slope through a voltage divider resistor network, and the switching state of the reset switch is controlled by a reset signal controlled by a pulse width modulation signal and a clock signal. By introducing a pulse width modulation control signal, this application ensures that the ramp signal generator operates only when the pull-up power transistor is on, effectively solving the subharmonic oscillation problem that may occur in buck-boost circuits when the duty cycle is greater than 50%. Simultaneously, the resistor voltage divider reduces the influence of the input voltage on the ramp signal, improving the circuit's stability and anti-interference capability.

The invention relates to a circuit for eliminating influence of oblique wave compensation on minimum and maximum peak current of an inductor, and belongs to the technical field of circuit structures. By adopting the circuit for eliminating the influence of the oblique wave compensation on the minimum peak current and the maximum peak current of the inductor, the minimum peak current and the maximum peak current of the inductor are only related to the set bias current and are not related to the oblique wave compensation amount. Therefore, the problem of subharmonic oscillation of the peak current mode step-down circuit is solved by utilizing oblique wave compensation, and the constancy of the minimum peak current and the maximum peak current is ensured. During light load, due to the fact that the minimum peak current is constant, under different duty ratios, the light load efficiency is not too low, and the output voltage ripple is not too large. During heavy load, the maximum peak current is constant. And the maximum load capacity is not influenced under each duty ratio. The circuit provided by the invention can be applied to peak current mode boost and peak current mode buck circuits.

This disclosure relates to a power converter, a slope signal generator and a slope signal generation method thereof. The power converter comprises an inductor and a switch transistor coupled between the input terminal and the output terminal. The slope signal generator comprises: a proportion transformation circuit, for performing proportion transformation on the current sense signal of the inductor to obtain a replicated signal; and an offset compensation circuit, for performing offset compensation on the replicated signal to obtain a slope signal, wherein the slope change of the slope signal characterizes the inductance value change of the inductor. The slope signal generator of the power converter can adaptively adjust the slope of the slope signal during the switching cycle, dynamically compensate for the fluctuation of the inductance value, improve the effect of suppressing subharmonic oscillation, thus enhancing the input and output voltage range and stability of the power converter.

The application discloses a single-sensor analog control method of a three-level flying capacitor step-down converter, and comprises the following steps: analyzing the on-off logic of each switch device when the three-level flying capacitor step-down converter circuit normally operates, and describing the circuit working state according to the coordinate sequence (Q1, Q2) formed by the first switch device and the second switch device; taking one of the working mode points (1, 0) as an example to analyze the influence of the flying capacitor voltage balance on the normal operation of the circuit and the voltage balance of the device; then, a single-sensor analog control method is proposed to control the three-level flying capacitor step-down converter; then, the static stability characteristics of the technology applied to the three-level flying capacitor step-down converter are studied; in view of the situation that the subharmonic oscillation is generated within a certain range, the subharmonic oscillation is eliminated by using a slope compensation mode, and the characteristic that the flying capacitor voltage is naturally balanced when the subharmonic oscillation is eliminated is verified; and the compensation slope strategy is applied to the analog control circuit.

The utility model relates to the technical field of digital power supply control, in particular to a slope compensation circuit. The main control unit is connected with the MCU and the DCDC power supply; comprising a power supply unit, a first slope compensation unit, a second slope compensation unit, an input interface A and an output interface B, a first external slope compensation unit and a second external slope compensation unit are added during current mode control of the digital switching power supply, so that control can be better realized, subharmonic oscillation is avoided, and external slope compensation is more stable and higher in linearity than internal slope compensation; and more flexible slope compensation is realized through matching with a driving signal given by the MCU unit.

The application discloses a control circuit of a switching converter and the switching converter. An output feedback signal and a reference signal are subjected to error amplification to obtain a compensation signal. The compensation signal is clamped according to a peak value of a ramp signal, so that the compensation signal is clamped at an upper limit voltage when the compensation signal is greater than or equal to a clamping voltage. A comparison signal is generated according to the compensation signal, the ramp signal and a ripple signal to control a switching state of a main switch tube of the switching converter. The application has high current limiting precision for inductance peak current, can perform overcurrent protection on inductance current, and does not cause sub-harmonic oscillation during overcurrent protection.