I have a design that has 3 power modules, PTH05050W and PTH04000W (x2). These are feed by a common 5V main supply.
PTH05050W - 5Vin, 3.3Vout, 3.0A max, step load 0.5A max
PTH04000W - 5Vin, 2.5V out, 1.0Amax, step load 0.30A max
PTH04000W - 5Vin, 1.2out, 1.5A max, step load 0.30A max
The data sheets call for input capacitor of 100uF, 47uF and 47uF minimum respectively. It is desirable to keep capacitance to a minimum for size and inrush reasons. According to appnote SLTA055, it seems that I "could" use less capacitance and meet my requirements.
http://focus.ti.com/analog/docs/litabsmultiplefilelist.tsp?literatureNumber=slta055&docCategoryId=1&familyId=561
Question - Can I safely use something less for input capacitors ? Concerns if I use less.
I currently have a 33uF tantulum and 10uF ceramic on each and everything seems OK. I just need to clarify if this is or is not OK.
There are 4 cap pads per input (two large, two small) that can be used for other caps if you have a better recommendation.
