Tuesday, April 8, 2008

What is Vcc Vdd Vee Vss?

Vcc and Vdd are the Positive voltages
Vcc - Positive supply voltage of a Bipolar Junction Transistor
Vdd - Positive supply voltage of a Field Effect Transistor

Vee and Vss are the Negative voltages/ground.
Vee - Negative supply voltage of a Bipolar Junction Transistor
Vss - Negative supply voltage of A Field Effect Transisto

The letters c, d, e and s originated from the name of the legs of the transistors Collector, Drain, Emitter and Source, respectively.

Why double suffix instead of single i.e. Why Vss instead of Vs?

The doubled suffix indicates that the voltage is "common", i.e. it is the supply voltage to one or more collectors (in the case of cc) and not just the voltage at a specific collector. Similarily, Vee is a common voltage for all emitters etc.

Reference: http://www.techpowerup.com/articles/overclocking/45


  1. Thanks for enlightenment, it is helpful. I always wondered why those subscripts are double digit.

  2. 你确定这是对的么?

    1. Let this be a lesson that we all should learn Chinese.

  3. About 1.43 years too late but…