1、电气英语证书考试(PEC)-Glossary of Electrical Engineering Terms11-Wire A single-wire (plus ground) communications protocol.1-Wire Master A 1-Wire interface master controller.10GbE 10-Gigabit Ethernet3G Third-generation mobile telephone protocols that support higher data rates, for non-voice communications su
2、ch as multimedia and Internet access.3GPP Third Generation Partnership Project, a collaboration of cell phone technology standards bodies.802.11 IEEE standard that specifies medium-access and physical-layer specifications for 1Mbps and 2Mbps wireless connectivity between fixed, portable, and moving
3、stations within a local area.802.11a The IEEE standard that governs the deployment of 5GHz OFDM systems. It specifies the implementation of the physical layer for wireless UNII b.802.11b An international IEEE standard for WLAN networks, operating at 2.4GHz and providing a maximum data transfer rate
4、of 11Mbps.802.11g A proposed standard that describes a wireless networking method for a WLAN that operates in the 2.4GHz radio band (ISM: Industrial Scientific Medical frequency band). It transfers data at up to 54Mbps.A-Weighting A-weighting is a standard weighting curve applied to audio measuremen
5、ts, designed to reflect the response of the human ear.Sound-pressure levels derived using A-weighting are denoted by “dBA,“ or A-weighted dB levels.A/D Converter Analog to digital. Specifically: A/D converter, a circuit that converts analog signals into a stream of digital data.AC Alternating curren
6、t: A signal or power source that varies with time, switching polarities. Typically, sinusodial and constant frequency.Accelerometer A sensor or transducer for measuring acceleration.ACPI Advanced Configuration and Power Interface: An industry-standard specification (co-developed by Hewlett-Packard,
7、Intel, Microsoft, Phoenix, and Toshiba) for operating-system-directed power management for laptop, desktop, and server computers. A replacement for APM.ACPR Adjacent (alternate)-channel power ratioACR Accumulated current registerADM Add/Drop Multiplexer: A synchronous transmission network (SDH or So
8、net) can carry multiple channels. An Add/Drop Multiplexer is a device that adds (inserts) or drops (removes) lower-data-rate channel traffic from the higher-rate aggregated channel.ADPCM Adaptive Differential Pulse Code Modulation: A compression technique that encodes only the difference between seq
9、uential samples.ADS Analog design systemADSL Asymmetric Digital Subscriber Line: A method for moving data over regular phone lines. An ADSL circuit carries much more data than a modem can encode on a regular phone connection. ADSL rides on the regular phone wires coming into the subscribers premises
10、 (twisted pair copper).AEC-Q100 A qualification test sequence for integrated circuits developed by the AIAG automotive organization.AFE Analog Front End: The analog portion of a circuit which precedes A/D conversion.AGC Automatic Gain Control: A circuit that modulates an amplifiers gain, in response
11、 to the relative strength of the input signal, in order to maintain the output power.Ah Ampere-hour(s): A measure of battery capacity. A 4Ah battery could, for instance, deliver 1A for 4 hours, 1/2A for 8 hours, etc.Air Discharge A method for testing ESD-protection structures in which the ESD genera
12、tor is discharged through an air gap between the generator and the device under test (DUT).AIS Alarm indication systemAISG The Antenna Interface Standards Group (AISG) creates open specifications for antenna-line control and monitoring for 3G systems.Source: Aliasing In A/D conversion, the Nyquist p
13、rinciple states that the sampling rate must be at least twice the maximum bandwidth of the analog signal. If the sampling rate is insufficient, then higher-frequency components are “undersampled“ and appear shifted to lower-frequencies. These frequency-shifted components are called aliases.The frequ
14、encies that shift are sometimes called “folded“ frequencies because a spectral plot looks like it was folded to superimpose the higher frequency components over the sub-Nyquist portion of the band.AM Amplitude Modulation: A modulation method in which the carrier amplitude changes with the input sign
15、al amplitude.Ambient TemperatureTemperature of the air surrounding a component.Ambient Temperature SensorTemperature sensor used to measure the temperature of the air that surrounds a component (the ambient temperature).AMLCD Active-matrix liquid-crystal displayAmp 1. Ampere2. AmplifierAmpacity The
16、amount of current a conductor can carry without exceeding its specified temperature, in amperes.Ampere Ampere(s), the unit of electrical current. Current is defined as the amount of charge that flows past a give point, per unit of time.The symbol I is used for current in equations and A is the abbre
17、viation for ampere.Ampere-hour A measure of charge (or current flow over time). One ampere-hour (or amp-hour or Ah) is a current of one ampere flowing for one hour. The amount of charge transferred in that hour is 3,600 coulombs (ampere-seconds). A milliampere-hour (mAh or milliamp-hour) is a thousa
18、ndth of an amp-hour. An ampere-second (A-s or amp-second) is an amp supplied for one second.A common use of the term is rating energy storage device capacity, especially rechargeable batteries. For example, a 12-volt, 7Ah rechargeable battery used in an alarm system will supply an amp at the rated v
19、oltage range for seven hours, 2 amps for 3.5 hours, etc. If my alarm consumes 250mA, this battery would operate the system for 28 hours. Amplifier An electrical circuit that produces an output that is a replica of the input. The output may be scaled or have increased drive, or it may provide isolati
20、on (so changes in output conditions do not affect the input or other outputs). It may perform other transformations (e.g., filtering or logarithmic drive).Amplifier Class Amplifier circuit types are divided into “classes“ which describe whether the amplifier operates in a linear or switching mode, a
21、nd any techniques used to restore linearity of output.AMPS Advanced Mobile Phone System: An analog only, 1G standard that operates in the 800MHz to 900MHz frequency band. It is still widely used in the United States.AMR Automatic Meter Reading: A system installed to read a utility meter remotely.Ana
22、log A system in which an electrical value (usually voltage or current, but sometimes frequency, phase, etc.) represents something in the physical world. The electrical signal can then be processed, transmitted, amplified, and finally, transformed back into a physical quality.For example: A microphon
23、e produces a current that is proportional to sound pressure. Various stages amplify, process, modulate, etc. Ultimately, a varying voltage is presented to a speaker which converts it back to sound waves.By contrast, a digital system handles a signal as a stream of numbers.Analog Switch An analog swi
24、tch (sometimes just called a “switch“) is a switching device capable of switching or routing analog signals (meaning signals that can have any level within a specified legal range), based on the level of a digital control signal. Commonly implemented using a “transmission gate,“ an analog switch per
25、forms a function similar to that of a relay.For example, an analog switch can turn an audio signal on or off based on a MUTE signal; or analog switches could send one of two signals to a headphone amplifier.Most commonly implemented using CMOS technology integrated circuits. Maxim makes hundreds of
26、examples.Analog Temperature SensorTemperature sensor with a continuous analog voltage or current output that is related, usually linearly, to the measured temperature.AND Combining two signals so that the output is on if both signals are present. This can be accomplished by an AND logic gate (two in
27、puts, one output which is high if both inputs are).ANSI American National Standards InstituteAnti-Aliasing An anti-aliasing filter is used before A/D conversion. It is a lowpass filter that removes signal components above the Nyquist frequency, thereby eliminating their sampled replicas (aliases) in
28、 the baseband.APC Automatic Power Control: Feature in laser drivers (such as the MAX3669) that uses feedback from the laser to adjust the drive, to keep the lasers output constant.APD Avalanche Photo Diode: A photodiode designed to take advantage of avalanche multiplication of photocurrent to provid
29、e gain. As the reverse-bias voltage approaches the break-down voltage, hole-electron pairs created by absorbed photons acquire sufficient energy to create additional hole-electron pairs when they collide with ions. Thus a multiplication or signal gain is achieved.API Application program interface: A
30、 software layer that allows a system to be programmed via a defined set of commands.APM Advanced Power Management: Power management standard for computers that provides five power states: Ready, Stand-by, Suspended, Hibernation, Off.APON ATM (-based) passive optical networkAPQP Advanced Product Qual
31、ity Planning. System developed by the AIAG automotive organization to communicate common product quality planning and control plan guidelines for suppliers to the automotive industry.ASCII American Standard Codes for Information InterchangeASIC Application-specific integrated circuit.ATE Automatic t
32、est equipment; automated test equipment. ATM Asynchronous transfer modeAuto Shutdown A feature in EIA-232 interface devices which puts the IC into a low-power shutdown mode when no signal is present on the EIA-232 bus.Autoshutdown Plus A feature in EIA-232 interface devices which puts the IC into a
33、low-power shutdown mode when no signal is present on the bus or the transmitter inputs.Autotransformer An autotransformer is a transformer that uses a common winding for both the primary and secondary windings. Essentially an inductor with a center-tap, an autotransformer is often used in power-supp
34、ly boost-converter applications to achieve a higher output voltage, while limiting the peak flyback voltage seen by the power switch.AWG 1. Arbitrary waveform generator2. American Wire Gauge: A measure of wire thickness (which also dictates cross-sectional area, and for a given material, ampacity).
35、Example: 24 AWG wire has a nominal diameter of 0.0201in or 0.511mm. Also called the Brown and Sharpe Wire Gauge. Note that steel wire is measured by a different gauge. AWG only applies to wire used to conduct electricity.B Bel: Measurement of a signals power compared to a reference; also, measuremen
36、t of sound pressure. See the more commonly used term, “decibel,“ or, “dB.“Backup Step-Up Step-up, switching-regulator power supply with a backup battery switchover.Bandwidth 1. Bandwidth (BW) is a range of frequencies, or information, that a circuit can handle or the range of frequencies that a sign
37、al contains or occupies.Example: An AM broadcast radio channel in the US has a bandwidth of 10kHz, meaning that it occupies a 10kHz-wide band, such as the frequencies from 760kHz to 770kHz.2. The amount of data a digital channel or line can handle, expressed in bits per second (bps), kilobits per se
38、cond (kbps), baud, or a similar measure.Base Station A base station (or basestation) is a wireless transceiver at a fixed location (e.g. atop a telephone pole) which is part of a wireless communications network, e.g. the cell phone network. Typically, the base station connects to any cell phones in
39、its area and relays the calls to the wired network.A femto base station is a smaller, personal base station which might cover a home or building and connect via a DSL Internet connection.Baseline The electrical signal from a sensor when no measured variable is present. Often referred to the output a
40、t no-load condition.Bass Boost Circuitry that boosts the bass response of the amplifier, improving audio reproduction, especially when using inexpensive headphones.Battery Backup A feature of microprocessor supervisory circuits and some power supplies to switch between a main power source and a batt
41、ery.Battery Freshness SealA feature in microprocessor supervisory circuits which disconnects a backup battery from any down-stream circuitry until VCC is applied the first time. This keeps a backup battery from discharging until the first time a board is plugged in and used, and thus preserves the b
42、attery life.Battery Fuel Gauge A feature or device that measures the accumulated energy added to and removed from a battery, allowing accurate estimates of battery charge level.Battery Monitor A feature that monitors the voltage on a battery and indicates when the battery is low. It is usually imple
43、mented using a comparator to compare the battery voltage to a specified level. May also include functions such as charging, remaining capacity estimation, safety monitoring, unique ID, temperature measurement, and nonvolatile (NV) parametric storage.Battery Switchover A circuit that switches between
44、 the higher of a main supply and a backup battery.BCD Binary-coded decimal: Representation of a number in which each decimal digit (0-9) is encoded in binary, with four bits per decimal digit.BER Bit Error Rate: A measure of the number of erroneous bits which can be expected in a specified number of
45、 bits in a serial stream.BERT Bit Error Rate (BER) Tester: A piece of test equipment which determines the bit error rate for a device under test (DUT).Beyond-the-Rails A feature of amplifiers that allows input or output voltages to exceed the supply rails.BGA Ball grid array: A packaging technology.
46、Bidirectional The device accommodates signals traveling either direction though a single channel.Bipolar Inputs An input which accommodates signals both above and below ground.Bipolar Junction TransistorA Bipolar Junction Transistor, or BJT, is a solid-state device in which the current flow between
47、two terminals (the collector and the emitter) is controlled by the amount of current that flows through a third terminal (the base).Contrast to the other main transistor type, the FET, in which the ouput current is controlled by input voltage (rather than by input current).BIST Built-in self-test.Bi
48、t Banging A technique which uses the general-purpose ports of a microcontroller to emulate a serial interface standard (I2C, SPI, etc).Bit Error Ratio The number of erroneous bits divided by the total number of bits transmitted, received, or processed over some stipulated period.Blade Server A blade
49、 server is a computer system on a motherboard, which includes processor(s), memory, a network connection, and sometimes storage. The blade idea is intended to address the needs of large-scale computing centers to reduce space requirements for application servers and lower costs.Blink Control Controls the display segment blink rate.BLM Ball limiting metalBluetooth A technology that allows voice and data connections between a wide range of mobile and stationary devices through short-range digital two-way radio. For instance, it specifies how mobile phones, Wireless Information Devices
