# What are abbreviations used in electrical engineering?

This question is meant to be a glossary of abbreviations used in electrical engineering.

Some abbreviations are very common and universal, and are therefore acceptable to use on this site. Others are quite localized or pet abbreviations used by individuals without a wide following, so are not acceptable on this site. One purpose of this question is to list all abbreviations so that others have a chance to decode them if encountered, but thru voting also show which ones are acceptable to use in a wide international context or not.

So here are some rules to make this question work:

1. Each answer must only be for ONE abbreviation.

2. This will be community wiki, so only ONE answer for each abbreviation. If you want to expand on a description, edit the existing answer for that abbreviation.

3. This is going to get long, so consistant formatting will help. For each answer (abbreviation), start with just the abbreviation within HTML "h1" and "/h1" tags on a line by itself.

4. Upvote answers for abbreviations you think would be acceptable to use in a post on this site without any expansion or explanation.

5. Downvote abbreviations (answers) you think should not be used "bare" on this site. This will be community-wiki, so nobody will loose reputation as a result. In this special case, you are voting on the universality of the abbreviation, not on the quality of the writeup. If you don't like the write up, fix it instead.

# INDEX

A - A(2) AC(7) ADC(15) ALU(3) AM(7) ASCII(12) ASIC(6) ASK(1) AWG(7)

B - BCD(5) BJT(16) BLDC(4) BNC(6) BPF(1) BW(3)

C - CAD(5) CAN(7) CC(1) CC-II(-1) CCCS(1) CCD(6) CMOS(16) CMRR(1) COG(0) CPLD(4) CPM(-1) CPU(7) CRO(-1)

D - DAC(15) DC(7) DEMUX(2) DFT(2) DIP(5) DLL(2) DMA(7) DRC(3) DSO(3) DSP(13) DTFT(0) DVD(-10) DVM/DMM(4)

E - ECL(4) EDA(6) EE(7) EEPROM(13) EMC(3) EMS(-7) EOS(0) EPROM(3) ESD(9)

F - F(2) FDNR(-3) FET(17) FFC(2) FFT(6) FIFO/LIFO(7) FM(7) FPGA(9) FSK(1) FSM(4)

G - GBW(5) GIC(-1) GND(16) GPIO(9) GPS(4)

H - H(2) HDTV(-11) HF(4) hFE(2) HPF(2) HVSP(-1) Hz(3)

I - i(-1) I/P(-7) I2S(1) IC(11) IF(4) IFT(1) IGBT(9) IGFET(0) ISP(4) I²C(13)

J - j(-1) JFET(10) JTAG(7)

K - KCL(6) KVL(6)

L - LCD(17) LED(19) LF(3) LPF(4) LSB, MSB(2) LUT(5) LVD(-1) LVDS(5) LVDT(0) LVS(-2)

M - MCU(6) MEMS(6) MIDI(4) MOSFET(17) MPU(-1) ms(2) MUX(6)

N - NEXT(-6) NPN(12) NTSC(0) NVM(0)

O - O/P(-7) OCXO(2) OLED(4) OP-AMP(8) OTA(3)

P - P-P(0) PAL (logic)(2) PAL (television)(0) PC(-1) PCB(17) PCBA(-5) PCM(4) PFM(-2) PIC(0) PID(9) PLL(9) PM(0) , duplicate(0) PNP(14) POR(3) PPM(-1) PSK(5) PUT(-1) PWM(24)

Q - QM(-6) QVGA(0)

R - RADAR(0) RAM(12) RF(5) RFID(6) RGB(4) RJ45(6) ROM(3) RTL (discrete logic)(2) RTL (Verilog)(2)

S - SAW(3) SCR(9) SD,SDHC(0) SDCC(-3) SMA(4) SMPS(9) SMT(5) SNR(5) SOC/SoC(5) SPI(13) SPICE(8) SRAM(6) SRPP(-2) STA(0)

T - TBH(-8) TCXO(2) THD(6) TRF(-1) TTL(10) TVS(4)

U - UART(12) UHF(4) UJT(0) UL(3) USART(4) USB(4)

V - V(2) VCA(1) VCC / VEE / VDD / VSS(14) VCCS(1) VCO(5) VCXO(3) VFD(3) VGA(-2) VHDL(7) VHF(5) VLSI(2) VNL,VFL(-1) VSWR(4)

W - W(2)

X - XO(1) XOR(3) XTAL(5)

Ω - Ω(0)

186 answers - Sun May 11 09:17:28 2014 (CET)

• IEEE's take on the subject May 12, 2014 at 19:41
• The links don’t seem to work. Not on iPhones anyway. May 19 at 23:06

# TCXO

Temperature Compensated Crystal Oscillator. Although a crystal oscillator is already pretty stable by itself, it does however vary its frequency with temperature. By measuring the temperature and adjusting other parameter(s) of the oscillator circuit to compensate, the output frequency is less influenced by external temperature variations.

## H

SI symbol for henry (measure of inductance), abbreviated as:

## mH

Millihenry - one thousandth (10-3) of a henry

## µH

Microhenry - one millionth (10-6) of a henry

## nH

Nanohenry - 10-9 henry

## F

SI symbol for farad (measure of capacitance), abbreviated as:

## pF

• -1. I'm downvoting all the unit posts. Do we have a goal to go all the way to the First Principles? I think, it's safe to expect the posters to be familiar with the SI system. May 2, 2014 at 5:52
• I agree that units probably shouldn't even be on this list, but at the same time, the down-votes make them look as though they are "unacceptable." I think they should at least have a positive score or be omitted from this list. May 2, 2014 at 15:10
• @NickAlexeev The title of the original question is "What are abbreviations used in electrical engineering?". How do these not fit that criteria? A newbie, running across the term pF, probably doesn't know what that is. It's more likely they have only seen µF in schematics. May 2, 2014 at 20:15

## W

Symbol for watt - measure of power (joules per second), abbreviated as:

## mW

Milliwatt - one thousandth (10-3) of a watt

## µW

Microwatt - one millionth (10-6) of a watt

## kW

Kilowatt - one thousand (103) watts

## MW

Megawatt - one million (106) watts

## GW

Gigawatt - 109 watt

• en.wikipedia.org/wiki/Long_and_short_scales May 1, 2014 at 18:52
• @jippie -- I am using the short scales, each new term is 1000 times (or 1/1000 times) the previous. See en.wikipedia.org/wiki/Gigawatt#Multiples May 1, 2014 at 22:04
• I'm not a native English speaker, but I thought 10^9 was commonly called billion. Whether it is the one or the other isn't really the point I wanted to make, my point is that it may be unclear for some. Other than that it is probably a detail we shouldn't worry too much about. May 2, 2014 at 5:43
• @jippie Thx, that was a typo (cut and paste from another answer). May 2, 2014 at 7:15

## A

SI symbol for ampere - measure of the amount of electric charge passing a point in an electric circuit per unit time, abbreviated as:

## mA

Milliampere - one thousandth (10-3) of an ampere

## µA

Microampere - one millionth (10-6) of an ampere

## nA

Nanoampere - 10-9 ampere

• I don't understand why such standard, common abbreviations as these would be down-voted. May 2, 2014 at 15:09

or

# DMX

A demultiplexer is a device taking a single input signal and selecting one of many data-output-lines, which is connected to the single input.

• DMX is likely to be confused with a stage lighting automation standard. May 5, 2014 at 11:20

# RTL (Verilog)

Register-Transfer Level. A subset of the Verilog / VHDL language that is synthesisable.

• Also Resistor-Transistor Logic, mostly obsoleted by TTL. Apr 30, 2014 at 15:24
• Check again. It's not 'Resistor' or 'Transistor' or 'logic' Apr 30, 2014 at 15:29
• I checked. Sometimes it is. doctord.dyndns.org/courses/Topics/Digital_Logic/digital/… Your move. Apr 30, 2014 at 15:31
• Huh, that's not what RTL is used for!! Apr 30, 2014 at 15:33
• Well it's true you won't see the original RTL very often nowadays. Apr 30, 2014 at 15:41
• @BrianDrummond is correct; RTL also stands for "Resistor Transistor Logic". There are also DTL, IIL, and a plethora of other digital logic families that didn't make it big. May 2, 2014 at 11:06
• @BrianDrummond I created a separate RTL (logic) entry. May 5, 2014 at 9:56

# PAL (logic)

Programmable Array Logic. Sometimes also sold under GAL.

# FFC

Flexible Flat Cable. (Or sometimes Flat Flexible Cable.) Usually refers to the thin, flat, high signal-density cables used for board-to-board or board-to-wire communication. They are commonly used on display modules and often have small pitch.

The board-to-wire connectors used to connect the cables are referred to as FFC connectors.

# I2S

Inter-IC sound. (sometimes reffed to as IIS). electrical serial bus used for connecting digital audio devices together. The I2S bus separates clock and serial data signals, it is the most common form of PCM audio data transmission in modern consumer electronics.

# POR

Power-on Reset. A microcontroller featuring a POR (the majority, if not all, modern micros) detects when the power is rising from below the operation threshold, and once it hits a sufficient level to operate stably, triggers a chip-wide reset that fully initializes all peripherals and registers to the specified initial state.

# SD,SDHC

Secure digital, Secure Digital High Capacity

# CMRR

Common Mode Rejection Ratio. Defined for an op-amp as: $$CMRR = \frac{Diff\ mode\ gain}{Common\ mode\ gain }$$

• I believe a better definition of CMRR for opamps is $\frac{\Delta V_{OS}}{V_{ICM}}$. I.e. The change in input offset voltage vs. change in input common mode voltage. CMRR is also relevant for matched bridges and for common-mode filters. May 18 at 7:42

# RTL (discrete logic)

Resistor-Transistor Logic, mostly obsoleted by TTL. There are also DTL, IIL, and a plethora of other digital logic families that didn't make it big

# STA

Static Timing Analysis: A method for verifying timing in digital design.

• May I know why down-voted? Apr 30, 2014 at 15:37
• Probably was somebody that doesn't know jack about digital design, I'll compensate when the vote counter resets. Apr 30, 2014 at 16:25
• It's a correct acronym, but I'd argue something that should be spelled out if used on this site. May 1, 2014 at 15:58

# CCCS

Current Controlled Current Source

## ms

Millisecond - one thousandth (10-3) of a second

## µs

Microsecond - one millionth (10-6) of a second

## ns

Nanosecond - one billionth (10-9) of a second

## ps

Picosecond - one trillionth (10-12) of a second

# VCCS

Voltage Controlled Current Source

# VCA

Voltage Controlled Amplifier

# DLL

Short for "Delay Locked Loop".

# BPF

Short for Band Pass Filter. A Band Pass Filter attenuates frequencies outside its pass-band, it attenuates frequencies below its lower cut off frequency and above its higher cut off frequency.

# QM

Quine-McCluskey, an algorithm for minimizing two level logic.

# TFT

Thin Film Transistor.

(A special kind of FET used in LCD.)

QAM

A digital (or analog) modulation scheme where the amplitudes of two orthogonal carrier waves (in-phase and quadrature) are modulated.

# DDR

Double data rate.

(As in DDR RAM)

# IEEE

Institute of Electrical and Electronics Engineers.

# HDMI

High-Definition Multimedia Interface. A compact audio/video interface for transferring uncompressed video data and compressed or uncompressed digital audio data from a HDMI-compliant source device to a compatible computer monitor, video projector, digital television, or digital audio device.

# BLE

Bluetooth Low Energy. Newest Bluetooth technology using Bluetooth 4.0 and has a range of 50m instead of 10.

(Only android 4.3 devices with BLE support can use BLE and apple products newer than the iPhone 4G).

# ISA

Instruction Set Architecture is an abstraction of a processing unit. It defines the instructions, register and memory to execute the program line by line. It can be implemented on FPGA or ASIC to become a processing unit.

For example, RISC-V is an open-source ISA.

# EMS

Electronic manufacturing services, companies that design, test, manufacture, distribute, and provide return/repair services for electronic components and assemblies for original equipment manufacturers (OEMs)