I have a little proyect where I will be using a SIM908 GSM module. in the SIM908 Hardware Guide it states that a diode array should be used to protect the SIM lines, recomending an ESDA6V1W5 (datasheet) or SMF05C (datasheet). the problem is those have a very small SMD footprint; I will probably try to use one of them on the final board, but was thinking if I could replace it with discrete PTH diodes for the prototype? and if so, what kind of diodes should i look for?
These are not simple diodes, these are special (TVS), high peak current "Zener" (actually,avalanche) diodes. You need to check the parameters,such as breakdown voltage, maximum power dissipation etc. I found something (www.ti.com/lit/ds/symlink/sn75240.pdf), but you'll need to double check the parameters.