Hello,, i cant find smf05c for ESD protection as referred in manual of Sim300c,,so is there any simple alternate?or will it be ok if do not include smf05c in the circuit?
You can use another unidirectional TVS diode from another company with the same voltage ratings. It also can be 5 separate diodes, and not a 5-diode array. THe circuit will work without it, but will be damaged more easily.