Team,
My customer likes the TPS76950, however he has concerns on the requirement of 0.2 to 10 Ohm ESR for the output capacitor:
I do not use tantalums unless there is no other way. An aluminum electrolytic can meet this 10SVPS10M. But at $0.58 and its size I would rather use a MLCC. Is the ESR requirement frequency dependent or independent (meaning across the entire frequency spectrum)?
MLCC ESR varies with frequency, according to this site http://ksim.kemet.com/Plots/SpicePlots.aspx.
For the C0805C475K8PACTU and others like it, the ESR is met at near 1KHz, but then it doesn’t reach the 0.2 ohm requirement again. This cap is ~ $0.07.
The input side is straight forward.
Is it safe to use this part alone?
Should I increase the value to compensate for the small ESR? I used the Kemet site and the 0805 ESR is pretty much the same up to 10uF. Case size does not seem to impact the ESR.
Should I put a series 1 ohm with it?
Thanks!
Viktorija