| A (amp) | Ampere |
| AA | Atomic absorption |
| AAF | Advanced Authoring Format |
| AAS | Atomic absorption spectroscopy |
| ABS | Antilock braking system |
| AC | Activated carbon |
| AC | Air Conditioner. |
| AC | Alternating Current |
| ACA | Anisotropically Conductive Adhesive |
| ACC | Adaptive Cruise Control |
| ACCESS | Analysis computer for component engineering services support |
| ACFA | Advanced CMOS Frame Aligner |
| ACI | Adjacent Channel Interference |
| ACI | After clean inspection |
| ACIA | Asynchronous Communications Interface Adapter |
| ACPR | Adjacent Channel Power Ratio |
| ACT | Actual Cycle Time |
| ACT | Alternative Control Techniques |
| ACWG | Asymmetrical CoPlanar Waveguide |
| AC/DC | Alternating current or direct current |
| ADC | Analog-to-digital converter |
| ADE | Advanced development environment |
| ADI | After develop inspection |
| ADIG | Application development interface guidelines |
| ADIO | Analog/digital input/output |
| ADMA | Advanced DMA controller |
| ADP | Administrative data processing |
| ADPCM | Adaptive differential pulse code modulation |
| ADS | Advanced Design System |
| ADSL | Asymmetric Digital Subscriber Line |
| ADT | Applied Diagnostic Techniques |
| ADT | Automatic Detection and Tracking |
| ADTV | Advanced Definition TV |
| AE | Acoustic emission |
| AE | Atomic emission |
| AE | Auger electron |
| AEC | Advanced Equipment Controller |
| AEC | Architecture Engineering and Construction |
| AECS | Automated Equipment Control System |
| AEI | After etch inspection |
| AEI | Automated equipment interface |
| AEM | Analytical Electron Microscopy |
| AES | Advanced Encryption Standard |
| AES | Auger Electron (Emission) Spectroscopy |
| AESA | Active Electronically Steered Array |
| AF | Audio frequency |
| AFAICS | As Far As Eyes Can See |
| AFC | Automatic flow controller |
| AFC | Automatic frequency control |
| AFD | Application framework definition |
| AFT | Automatic fine tunung |
| AGC | Automatic gain control |
| AGP | Accelerated Graphics Port |
| AGV | Automated guided vehicle |
| AI | Adobe Illustrator image format |
| AI | Artificial Intelligence |
| AICTE | All India Council Of Technical Education. |
| AIS | Adhesive Interconnect System |
| ALD | Atomic Layer Deposition |
| ALE | Application Logic Element |
| ALS | Advanced light source |
| ALS | Advanced low-power Schottky |
| ALU | Arithmetic logic unit |
| ALVT | Advanced low voltage technology |
| AM | Amplitude Modulation. |
| AM | Ante Meridian (before noon) |
| AMD | Alpha micro devices |
| AMDM | ATM Multiplexer/DeMultiplexer. |
| AMH | Automated material handling |
| AMHS | AMH Systems |
| AMI | Alternate Mark Inverse Code |
| AML | Automatic model linking |
| AMLCD | Active Matrix LCD |
| AMM | Acoustic Mismatch Model |
| AMM | Analog multimeter |
| AMPS | Advanced Mobile Phone Systems. |
| AMRAAM | Advanced Medium Range Air-to-Air Missile |
| AMT | Advanced manufacturing technology |
| AMU | Atomic mass unit |
| AM/FM | Amplitude modulation or Frequency modulation |
| ANA | Automated Network Analyzer |
| ANN | Artificial Neural Network |
| ANSI | American National Standards Institute |
| AOI | And-Or-Invert |
| AOI | Automatic Optical Inspection |
| AOV | Air-Operated Valve |
| AP | Adhesion Promoter |
| APA | Advanced Performance Algorithm |
| APB | Anti Phase Boundary |
| APC | Advanced Process Control |
| APC | Automatic phase control |
| APCD | Add-on Pollution Control Devices |
| APCFI | Advanced Process Control Framework Initiative |
| APCVD | Atmospheric Pressure Chemical Vapor Deposition |
| APC-7 | Amphenol Precision Connector, 7 mm |
| APD | Avalanche Photo Diode |
| APDP | Anti-Parallel Diode Pair |
| APEC | Advanced Process Equipment Control |
| API | Application Programming Interface |
| API | Atmospheric Pressure Ionization |
| APIMS | Atmospheric Pressure Ionization Mass Spectroscopy |
| APM | Acoustic Plate Mode |
| APM | Atmospheric Passivation Module |
| APS | American Physical Society |
| APS | Antenna Positioning System |
| APT | Advanced Probe Technology |
| APT | Automatically Programmed Tools |
| APW | Augmented Plane Wave |
| AQI | ACCESS Query Interface |
| AQL | Acceptance Quality Level |
| AQTX | Aquatic Toxicity |
| AR | Aspect Ratio |
| ARAMS | Automated Reliability, Availability, and Maintainability Standard |
| ARC | Antireflective Coating |
| ARCOFI | Audio Ringing Codec Filter |
| ARDE | Aspect-Ratio-Dependent Etching |
| ARIB | Association of Radio Industries and Businesses |
| ARIMA | Auto Regressive Moving Average with Integration |
| ARINC | Aeronautical Radio Incorporated |
| ARO | After Receipt of Order |
| ARPA | Advanced Research Projects Agency |
| ARPES | Angular Resolved Photo Electron Spectroscopy |
| ARPU | Average Revenue Per User |
| ARS | Angle-Resolved Scattering |
| ARUPS | Angle-Resolved UV Photoemission Spectroscopy |
| ARXPS | Angle Resolved XPS |
| ASAP | Advanced Stepper Application Program |
| ASCII | Alphabetic Code For Information Exchange |
| ASCII | American Standard Code for Information Interchange |
| ASE | Amplified Stimulated Emission |
| ASF | Windows Media Technology File Format |
| ASIC | Application Specific Integrated Circuit. |
| ASIC | Application Specific Semiconductor |
| ASK | Amplitude Shift Keying. |
| ASLAC | Advanced Subscriber Line Audio processing interface |
| ASLIC | Advanced Subscriber Line Interface |
| ASLV | Augmented Sattelite Launch Vehicle. |
| ASO | Automatic Shut-Off |
| ASP | Advanced Simple Profile |
| ASP | Advanced Strip and Passivation |
| ASP | Advanced Strip Processor |
| ASP | Application Service Provider |
| ASR | Automated Send Receive |
| ASSMBE | All Solid Source MBE |
| ASSP | Application Specific Standard Product |
| ASTM | American Society for Testing and Materials |
| ASTTL | Advanced Schottky TTL |
| ASW | Augmented Spherical Wave |
| AS/RS | Automated Storage and Retrieval System |
| AT & T | American Telegraph and Telegraph Co.Ltd. |
| ATC | Air Traffic Control. |
| ATDF | Advanced Tool Development Facility |
| ATDSEM | Apply/Develop Track Specific Equipment Model |
| ATE | Automatic Test Equipment |
| ATF | Automation Test Facility |
| ATG | Automatic Test Generation |
| ATLAS | Abbreviated Test Language for All Systems |
| ATM | Adobe Type Manager |
| ATM | Asynchronous Transfer Mode. |
| ATM | Atmosphere |
| ATM | Automatic Teller Machine |
| ATP | Advanced Technology Program |
| ATPG | Automatic Test Pattern Generation |
| ATR | Air Transport Rack |
| ATR | Anti Transmit-Receive cells |
| ATR | Attenuated Total Reflectance |
| ATR-FTIR | Attenuated total reflectance Fourier transform infrared spectroscopy |
| ATSC | Advanced Television Systems Committee. |
| ATT | Attenuated |
| AVC | Automatic Volume Control |
| AVP | Advanced Vertical Processor |
| AVRC | Audio Visual Research Centre |
| AVS | Advanced Visualization System |
| AVT | Accelerated Vesication Test |
| AWE | Asymptotic Waveform Evaluation |
| AWG | American wire gauge |
| AWG | Arbitrary Waveform pattern Generator. |
| AWGN | Additive White Gaussian Noise |
| AWS | Advanced Wet Station |
| A/D | Analog to digital |
| Ac | Actinium |
| Ag | Silver |
| Ah | Ampere hour |
| Ai | Current gain |
| Al | Aluminum |
| ALT | Alternating |
| Amp | Amplifier |
| AND | Logic term - AND |
| antilog | Antilogarithm |
| Ap | Power gain |
| As | Arsenic |
| ASPaRC | Ability of Solder Paste to Retain Components |
| Async | Asynchronous |
| Au | Gold |
| Av | Voltage gain |
