Yes probably - but SD and microSD card interfaces are fussy as their I/O is designed for 50MHz signallingin native mode rather than slow SPI from a microcontroller. A 16MHz Arduino can drive 8MHz SPI, ie clockhigh and low times are 62.5ns, so rise and fall times of 20ns or better would be advisable for that I think. Most devices would be more like 10pF than 40pF I hope.

Yeah, I was looking at a worst case situation, which still didn't look all that bad. Of course,

if you halve the R values and assume 10pF, then R*C is more like 8 nsec.

Also, where does the 1.6k come from in the calculation? 4k7 - 2k4 = 2k3... Not from there.

Good time to take a look at Thevenin's Theorem. The Thevenin equivalent resistance for the

voltage-divider, when looking into the output node, is the parallel combination of 4.7K and

2.4K, which is 1.6K.

http://en.wikipedia.org/wiki/Th%C3%A9venin's_theorem