hi,
i am designing a sim 300 modem. I want to know how to design the power supply,what are the components to be used,their values , what about the specifications and the logic diagram. where can i get the required details?
It's best if your power supply provides about 4.2V to the SIM300 – at lower voltages the module is more susceptible to noise. The module can draw as much as 2A when transmitting, so your power supply must have good load regulation and it must be well filtered to prevent ripple and noise. I use an LM317T regulator with a 4700uF cap on the input and a 2700uF cap on the output. Also, make sure you have filter caps right at the power pins.