If you are using the audio inputs/outputs then you should seperate the analog and digital grounds and connect them at only one point. Any analog components should connect to the analog ground only.
thx for reply GSM MAN
yes i am using audio input and outputs i am regulating 12 battery volt in to 5 volt so there is only one ground how i seprate digital and analog ground????
i apriciate yr quick reply
Typically your board would have a ground plane. Since you are using the audio I/O pins, you should have 2 ground planes - one for digital and one for analog. All of your analog components should use the analog ground plane, and all of your digital components should use the digital ground plane. The 2 ground planes should be connected at only one point. Typically this is at the SIM300's analog ground pin. By seperating the grounds you keep the digital an analog signal return paths seperate, and therefore keep digital noise from getting into the analog ground.
You may want to consult the SIM300 Handset Design Notes which you can download from: **broken link removed**
all i understend is to keep my analog and digital ground track seprate (in PCB) and to provide return path connect these track only at one point (to reduce noise and interference etc).
Correct me if i am wrong
and thanks for help again
Correct. However, I would recommend you consult the SIM300 Handset Design Notes I referenced in my earlier post. It provides a lot of useful information that you need to know if you want to get reasonable performance from the audio I/O.
hi all!
i have a project "SEND SMS FROM SIM MODULE SIM300CZ VERSION 3.04 TO MOBILE".
I FIND DATADHEET OF MODULE SIM300CZ V3.04 BUT I DONT FIND EVERYTHING ABOUT IT!
HELP ME!
MY EMAIL: TRUONG_GIANG2211@YAHOO.COM
THANKS EVERYBODY!
It would help if you indicated what type of information you are looking for - AT commands, hardware design spec, etc. However, if you just do a Google search you'll get plenty of hits to all types of documents relating to the SIM300.
thanks "GSM MAN",but i found many version of module sim300cz,but they're different pins(location),VBAT changed <=> GND, therefore ,i am power on ==> DIED!!!
i am using module sim300cz version 3.04 !
can u give me document detail about it (same version 3.04)?
thanks!
The pinouts are different between different models - SIM300, SIM300C, SIM300D, SIM300W. But I don't believe they have ever changed pin out on the same model. The www.Sim.com web site may have the information you are looking for.
thanks for relay GSM man!! YES,of course!(different between sim300cz,sim300d,sim 100,sim200..and very much version !!)
but I had read very much document for Sim 300CZ ,therefore i'm sure about pinouts of Sim300cz.
B/c ,i have only one sim300cz!hii.i found document about 4 months!!!
help me!
truong_giang2211 can you give me the schematic of your homemade develepment board please, i need it soon enough, but i can't find it on the net,
thx anyway..