Buck converter with adaptive slope compensation

Abstract

The invention discloses a Buck converter with adaptive slope compensation, which is characterized in that a first transconductance amplifier calculates the difference between a feedback voltage and areference voltage to obtain an original control current; a second transconductance amplifier calculates the difference between the feedback voltage and the reference voltage, superposes the differencecurrent and the current of a second current source to a second capacitor, controls a second switch through a signal output by the Q output end of a D trigger to form a slope voltage with a variable slope, and a fourth transconductance amplifier generates a slope current with a variable slope; a third transconductance amplifier forms a current containing output voltage information according to thevoltage difference between the first voltage source and the ground; a current multiplier multiplies the original control current by the slope current with the variable slope and divides the current with the output voltage information to obtain adaptive slope current with control information, then the adaptive slope current is converted into an adaptive slope voltage signal through a first resistor, the adaptive slope voltage signal is connected to the forward input end of a first comparator, and a comparison signal controls a driving module.

Description

technical field [0001] The invention belongs to the technical field of analog integrated circuits, and in particular relates to an adaptive slope compensation Buck converter. Background technique [0002] In the traditional constant on-time (COT, Constant On-Time) controlled Buck converter with fixed slope compensation, such as figure 1 As shown, the inductor current and the voltage generated by the sense resistor V L , EA output control voltage V C and the fixed ramp RAMP are compared whenever the inductor current produces a voltage V L When it is lower than the sum of Vc and RAMP, the output of comparator COMP1 is high, producing a constant on-time T on , so that the inductor current increases; when T on After the end, the inductor current decreases and returns to the valley value again, entering the next T on cycle, thereby controlling the Buck converter. [0003] The traditional fixed-slope compensation constant on-time controlled Buck variator has a good signal-to...

AI Technical Summary

Problems solved by technology

However, the traditional fixed-slope compensation constant on-time control buck converter has the following problems: (1) Compared with the traditional constant on-time control buck converter, due to the introduction of the slope, it leads to more introduction in the frequency domain a pole, causing the system to slow down in transient response

(2) In addition, when the inductor current ripple is large, because the slope of the inductor current and the voltage generated by the sampling resistor is large enough, there is no need for excessive slope compensation. Excessive compensation will reduce the unity gain bandwidth and affect responding speed

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