Hi,

I have a design which is a simple alarm system with two relays and the maximum spike current is about 200mA. I am using a 5 volt regulator (digikey# 296-12290-1-ND) but I can't figure what is the best choice of capcitors to use. On the output side, I have a .1uF for the electronics but I also have a 1500uF for transients in the circuit. My question is more about the input capacitor. What size but also what type of capacitor should I use. For this specific voltage regulator, TI says they used a .33uF on the input but they don't mention what type. Does the type really matter? As a general rule when making the power supply circuit, should a common design be used for all types of circuits? Thanks in advance for the help.

Chris