What is the difference between VCC, VEE, VDD, and VSS in microcontroller pins?

• V_CC
  • V_CC is used as the positive supply voltage for circuits using a bipolar transistor (BJT).
  • The "C" in "V_CC" stands for Collector.
  • It is widely believed that the reason for repeating "V_CC" and "C" twice is to distinguish it from the collector voltage V_C.
• V_EE
  • V_EE is used as a negative supply voltage for circuits that use a bipolar transistor (BJT).
  • The "E" in "V_EE" stands for Emitter.
  • It is widely believed that the reason for repeating "V_EE" and "E" twice is to distinguish it from the emitter voltage V_E.
• V_DD
  • V_DD is used as the positive supply voltage for circuits that use a field-effect transistor (FET).
  • The "D" in "V_DD" stands for Drain.
  • It is widely believed that the reason for repeating "V_DD" and "D" twice is to distinguish it from the drain voltage V_D.
• V_SS
  • V_SS is used as the negative supply voltage for circuits that use a field-effect transistor (FET).
  • The "S" in "V_SS" stands for Source.
  • It is widely believed that the reason for repeating "V_SS" and "S" twice is to distinguish it from the source voltage V_S.

Meaning of V_CC

V_CC is used as the positive supply voltage for circuits using a bipolar transistor (BJT).

The positive supply voltage on the collector side of the NPN bipolar transistor is "V_CC". The collector terminal of an NPN bipolar transistor is often connected directly to V_CC or V_CC through a resistor or other means.

Meaning of V_EE

V_EE is used as a negative supply voltage for circuits that use a bipolar transistor (BJT).

The negative supply voltage on the emitter side of the NPN bipolar transistor is "V_EE". The emitter terminal of an NPN bipolar transistor is often connected directly to V_EE or V_EE through a resistor or other means. In the case of a single power supply system, "V_EE" is at the same potential as the ground.

Meaning of V_EE

V_EE is used as a negative supply voltage for circuits that use a bipolar transistor (BJT).

The negative supply voltage on the emitter side of the NPN bipolar transistor is "V_EE". The emitter terminal of an NPN bipolar transistor is often connected directly to V_EE or V_EE through a resistor or other means. In the case of a single power supply system, "V_EE" is at the same potential as the ground.

Meaning of V_DD

V_DD is used as the positive supply voltage for circuits that use a field-effect transistor (FET).

The positive supply voltage on the drain side of the N-channel field-effect transistor (NchFET) is "V_DD". The drain terminal of an N-channel field-effect transistor (NchFET) is often connected directly to V_DD or V_DD through a resistor or other means.