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power-supply pin
(Redirected from vdd)

power-supply pins (or power-supply terminals) are pins on integrated circuit packages that go to the die's common power rails.

Terms[edit]

While their usage varies from one manufacturer to another, most terms are more common to a specific technology. Some notable exceptions are known to exist, for example Intel used Vcc and Vss to represent +5V and 0V on some of their chips.

BJT FET Description
Vcc Vdd V+ Vs+ + Positive supply voltage
Vee Vss V- Vs- VGND - GND Negative supply voltage

Double letters[edit]

The letter following the V is used to represent the voltage the power supply should be providing for that transistor's terminal (C for collector, D for drain, E for emitter, and S for source). For example Vcc means the voltage that should be delivered from the power supply to the collector. Note that this is different from Vc which means the voltage of the collector itself.

See also[edit]