Hi
What is the difference between the 2 3V3 or VCC symbols? Between the bar and the upwards arrow.
Thanks!
It would be better to post the drawing your looking at, but usually 3V3 stands for 3,3V and VCC is the
positive voltage of a entire PCB.
VCC designates the positive supply rail for bipolar logic circuits. The corresponding designation for FET circuits is VDD although they are sometimes confused. Which symbol is used for a rail depends on which cad program you are using
Many devices have a range of operating voltages, so Vcc can be used when you don't
want to imply any particular value for the logic supply.
If people were consistent Vcc / Vee would be used (or Vdd / Vss) but almost always
the 0V rail is "GND" or "0V". The names are accidents of history as CMOS has device
sources connected to both rails, so they should both be Vss (n-FETs to the GND rail,
p-FETs to the positive rail). Its not unusual to see Vcc / Vss which is mixing logic
families!
With faster logic processes and lower voltages designations like Vio or Vcore are getting
more common, especially as actual supply voltage is often under software control
with modern computer hardware.
In the Arduino world 5V and 3V3 are commonplace, as its important to get this
right (any confusion could lead to circuit damage).
Thanks for the responses!
I am clear now on the differences between VCC and 3V3.
What about between the two 3V3, between the white upwards arrow and the bar?
Edit: The example was taken from Mikroe's GSMClick schematic
http://www.mikroe.com/downloads/get/1921/gsm_click_manual_v101c.pdf