Ripple injection stability criteria for D-CAP / TPS53355

Hello,

I found two differential equations of stability criteria for D-CAP mode with ripple injection approach from slva453,TPS53355 datasheet.
Could you please let me know the reason of this difference ?

I think that
N = 1/(2π x Fsw x (R1 x R2) / (R1 + R2))
from the following equations.

-SLVA453
 L x Cout / (Rr x Cr) > ton / 2
 Cr > Cc > 1/(2π x Fsw x (R1 x R2) / (R1 + R2))

-TPS53355
 L x Cout / (Rr x Cr) > N x ton/2

Please see the attached file as equations summary.
8473.20141015_DCAP Ripple injection Approach.pdf

Best Regards,
Ryuji Asaka