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65DC-DC Converter Design and Magnetics

compare a signal A  B with a signal C, that is e

xactly equivalent to comparing A to C  B.

And in both cases, equality at the input pins is established when A  B  C.

This technique is called slope compensation , and is the most recognized way of

quenching the alternate wide and narrow pulsing (or subharmonic instability) associated

with current-mode control (see lower half of Figure 3.10 ).

It can be shown that to avoid subharmonic instability, we need to ensure that the amount

of slope compensation (expressed in A/s) is equal to half the slope of the falling inductor

current ramp, ...