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Help me understand the VDD_EXT pin in SIM300C

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mcihangir

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sim300c jpg

I will use a SIM300C Module for a project. I read datasheet and some another documents about SIM300 but i can't understand about VDD_EXT pin.
1) I don't need VDD_EXT functitons so can i leave it floating?
2) Do i have to connect to VDD_EXT pin with a LDO?
3)
my.php

Why connect LDO to VDD_EXT pin In this picture ? I take this picture from SIM300 evb schema.
https://img23.imageshack.us/my.php?image=71569875oo7.jpg
thank you
 

nisarg001

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sim300c pic

There are two functions of VDD_EXT
1. You can check your system is working or not. If voltage is HIGH at pin means module is working.
2. You can give supply of 3.0V to external citcuit. This is not often used.

If you don't want to use you can leave it floating...
 

sabeti_1990

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sim 300c project

it's ok
this pin just is an output
when the module powered on this pin have a 3Volt (for turning on other device)
be success
 

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