| CPC H02M 3/1586 (2021.05) [H02M 1/0025 (2021.05); H02M 3/1584 (2013.01)] | 16 Claims |
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1. A control device of a multi-phase DC/DC converter that generates an output voltage from an input voltage by using an output-stage circuit including a plurality of channels, each of the plurality of channels has a switching transistor, a coil and a rectifying element, the control device comprising:
an error signal generation circuit, configured to generate an error signal between a feedback voltage and a reference voltage according to the output voltage;
a current detection circuit, configured to, for each of the plurality of channels, analog-to-digital (A/D) convert a target current flowing through the switching transistor during an ON period of the switching transistor to derive a detected current value of the target current;
a pulse-width modulation (PWM) modulation circuit, configured to, for each of the plurality of channels, generate a PWM signal based on the error signal and a current corresponding signal according to the target current; and
a plurality of drive circuits, corresponding to the plurality of channels, each drive circuit driving a corresponding switching transistor based on a corresponding PWM signal,
wherein the PWM modulation circuit
derives an average value of a plurality of detected current values corresponding to the plurality of channels,
specifies a channel corresponding to the detected current value having a greatest difference from the average value as a target channel, and
generates the PWM signal corresponding to the target channel such that the current value of the target current in the target channel approaches the average value,
wherein the PWM modulation circuit includes a plurality of modulation blocks corresponding to the plurality of channels,
each modulation block including:
a comparator, configured to
compare a first comparison input signal based on the error signal with a second comparison input signal based on the corresponding current corresponding signal, and
output a signal indicating a comparison result; and
a superposition circuit, configured to superimpose an offset signal on the first comparison input signal or the second comparison input signal,
each modulation block generating a corresponding PWM signal based on the output signal of the comparator, wherein
the PWM modulation circuit adjusts the offset signal for the target channel such that the current value of the target current in the target channel approaches the average value.
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