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I am working on Buck Converter design based on LT8642S controller and trying to do average modelling ,so I contacted manufacturer regarding slope compensation info and they responded below.

"The slope comp information can actually be extracted from the datasheet enter image description here

To get the slope comp info in terms of VC voltage, we should get the VC pin to switch current gain (Rcs): 1/8.5 = 117.65mV/A enter image description here

Then slope comp gain becomes d(Ipeak) per 100% duty cycle x Rcs = 661.8mV This provide the slope comp info in terms of VC voltage."

I am unable to make sense of the above response from the manufacturer ,Can anyone please help?

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I think what they are saying is:

The graph shows the current limit at different duty cycles and this current limit is a combination of the slope compensation and the current sense. The effective current sense comes from the "Vc pin to Switch Current Gain" 8.5 A/V. This is Rcs = 117.65 mV/A (Ohms).

Extrapolating the graph to D=0 the current limit would be 18.0625A (This is the current limit without slope compensation) hence Vc can be found (18.0625/8.5). Vc = 2.125V.

Extrapolating the graph to D=1 the current limit would be 12.4375A and the current sense voltage would be (12.4375/8.5) ~1.4632V so the approx slope compensation voltage would be 2.125 - 1.4632 = 661.8mV.

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  • \$\begingroup\$ @Mark_D..Many Thanks Sir..I really appreciate for answering ,now its quite clear to me . \$\endgroup\$
    – Power Path
    Commented Jun 11 at 9:35

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