A segmented slope compensation circuit applicable to a
BUCK converter belongs to the technical field of an
electronic circuit. An oscillator circuit is used for introducing output
voltage informationof the
BUCK converter, a negative input end
voltage of an
operational amplifier is clamped to a positive input end
voltage thereof, a first
capacitor is charged by a
current mirror, the negative inputend voltage, namely a slop voltage
signal, of the
operational amplifier is obtained, the slop voltage
signal is compared with a second reference voltage to obtain a periodic slope voltage
signal, a slope
current generation circuit is used for generating compensation slopes with different slope rates under different duty ratios, a slope voltage correlated to the duty ratios is generated on a sampling
resistor after passing through a slope summing circuit, and a base
current compensation circuit is used for stabilizing a
system. Compared with a traditional slope compensation circuit, the segmented slope compensation circuit has the advantages that the
system stability is improved by employing different slope compensation rates under different duty ratios; and with the adoption of a
triode as a buffer, the segmentation accuracy is improved.