IC power-supply pin

IC power-supply pins denote a voltage and current supply terminals in electric, electronics engineering, and in integrated circuit design.^[a] Integrated circuits (ICs) have at least two pins that connect to the power rails of the circuit in which they are installed. These are known as the power-supply pins. However, the labeling of the pins varies by IC family and manufacturer. The double subscript notation usually corresponds to a first letter in a given IC family (transistors) notation of the terminals (e.g. V_DD supply for a drain terminal in FETs etc.).

Typical supply-pin labeling
	NPN BJT^[b]	N-FET			AC/DC^[c]	DC	DC
Positive supply voltage	V_CC/V_BB	V_DD	V+	V_S+	VIN	VDD	VA
Negative supply voltage	V_EE	V_SS	V−	V_S−
Ground	GND	GND	0	0	GND	GND	GND

The simplest labels are V+ and V−, but internal design and historical traditions have led to a variety of other labels being used. V+ and V− may also refer to the non-inverting (+) and inverting (−) voltage inputs of ICs like op amps.

For power supplies, sometimes one of the supply rails is referred to as ground (abbreviated "GND") – positive and negative voltages are relative to the ground. In digital electronics, negative voltages are seldom present, and the ground nearly always is the lowest voltage level. In analog electronics (e.g. an audio power amplifier) the ground can be a voltage level between the most positive and most negative voltage level.

While double subscript notation, where subscripted letters denote the difference between two points, uses similar-looking placeholders with subscripts, the double-letter supply voltage subscript notation is not directly linked (though it may have been an influencing factor).^[3]^[4]

^ ^a ^b Cite error: The named reference :1 was invoked but never defined (see the help page).
^ Horowitz, Paul (2015). The art of electronics. Winfield Hill (3 ed.). New York, NY, USA. ISBN 978-0-521-80926-9. OCLC 904400036.{{cite book}}: CS1 maint: location missing publisher (link)
^ Micro E, 7. Integrated circuits.
^ Op-amps: Some Standard Conconfigurations and Applications, Fall 2012.^{[permanent dead link]} Washington and Lee University, Lexington, VA.

Cite error: There are <ref group=lower-alpha> tags or {{efn}} templates on this page, but the references will not show without a {{reflist|group=lower-alpha}} template or {{notelist}} template (see the help page).

[:1-1] Cite error: The named reference :1 was invoked but never defined (see the help page).

[:0-3] Horowitz, Paul (2015). The art of electronics. Winfield Hill (3 ed.). New York, NY, USA. ISBN 978-0-521-80926-9. OCLC 904400036.{{cite book}}: CS1 maint: location missing publisher (link)

[6] Micro E, 7. Integrated circuits.

[7] Op-amps: Some Standard Conconfigurations and Applications, Fall 2012.^{[permanent dead link]} Washington and Lee University, Lexington, VA.

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