Glossary Terms and Definitions Beginning with the Letter T

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T/H Track/hold
T/R Transmit/receive
T/s See Transfer
T1 T1 is standard for digital transmission in the United States. It is a digital transmission link with a capacity of 1.544Mbps. T1 uses two pairs of normal twisted wires, the same as found in most residences. T1 normally handles 24 voice conversations, each one digitized at 64kbps. With more advanced digital voice encoding techniques, T1 can handle more voice channels.
T1 Framer See Framer
T3 A type of data connection capable of transmitting a digital signal at 44Mbps. T3 lines are often used to link large computer networks, such as those that comprise the Internet.
Tach See Tachometer
Tachometer A transducer used for measuring the rate of revolution of a shaft.
TAD Total accumulated discharge (mA-hr)
tank circuit See Resonant Circuit
Taper In a potentiometer, taper refers to how the resistance varies as the pot's armature is rotated (or, for a slide pot, as its wiper slides; or for a solid state pot like the DS1802, as its input voltage is varied).

For a pot with a linear taper, the resistance varies linearly as the wiper moves.

For a pot with a logarithmic (log) taper, the resistance varies logarithmically with the wiper's motion. When used in an amplifier circuit, the output varies slowly as the pot is operated at the low end and varies more and more rapidly as the pot is operated toward the high end.

This is also called an audio taper because it is most commonly used for audio volume controls. The ear responds logarithmically (each doubling in signal is perceived as an equal step in volume). The ear is more sensitive to changes at lower volumes, so an audio volume control varies the signal slowly at lower settings and more rapidly at higher settings. The net effect is that the sound seems to vary smoothly through the pot's range.

The perceived volume is subjective and fairly imprecise, so an approximation may be used instead of a true log pot. Example: See application notes AN 3996, AN 838, AN 1828.

TC Temperature coefficient; thermocouple; TURBOCHARGE (control bit)
TCP/IP Transmission Control Protocol/Internet Protocol: The protocols or conventions that computers use to communicate over the Internet.
TCXO Temperature Compensated Crystal Oscillator: A crystal oscillator that includes circuitry that compensates for temperature variations, to maintain a more constant frequency.
Td-SCDMA See TDSCDMA
TDD Time Division Duplex, the second variation of WCDMA especially suited to indoor environments where there is a need for high traffic density.
TDD WLAN See TDD
TDD-WCDMA See TDD
TDM Time Division Multiplexing, a scheme in which numerous signals are combined for transmission on a single communications line or channel. Each signal is broken into many segments, each having very short duration.
TDMA Time Division Multiple Access: A method of digital wireless-communications transmission. TDMA allows many users to access (in sequence) a single radio-frequency channel without interference, because it allocates unique time slots to each user within each channel.
TDMoIP See TDMoP
TDMoP TDMoP (TDM over Packets), or TDMoIP (TDM over IP), is the implementation of TDM over a packet-switching network. TDMoIP is a trademark of RAD Communications.

See:

TDR
Time-delay relay
Time-domain reflectometry
TDSCDMA Chinese Third Generation (3G) telecommunications standard. China's government allocated three frequency bands: 1880MHZ to ~1920MHz, 2010MHz to ~2025MHz, and 2300MHz to ~2400MHz.
TEC A thermoelectric cooler (TEC) is a small cooling device that relies on a Peltier junction. Composed of two conductors made of different materials, a Peltier junction (discovered in 1833 by J.C. Peltier) acts as a heat pump which can cool or warm when current is passed through it.

The small size of the TEC allows precision thermal control of individual components such as fiber optic laser drivers, precision voltage references, or any other temperature critical device. Temperature-critical components are integrated with a TEC and a temperature monitor into a single thermally-engineered module.

A "thermoelectric controller" (also abbreviated TEC) is an electronic circuit that controls the current that drives the junction. These can be quite sophisticated. Many can drive a positive or negative current (so they can heat or cool), use PWM for efficiency, and incorporate control to regulate the amount of current. Examples of such circuits are linked below.

See: App Note 3318, HFAN-08.2.0: Thermoelectric Cooler (TEC) Control.

TEDS See Transducer Electronic Data Sheet
Television A system for transmitting picture and sound over a distance, primarily via the standards for NTSC, PAL, or HDTV.

See: Video Basics

Temp See Temperature
Temp Sensor See Analog Temperature Sensor
Tempco Temperature coefficient
Temperature The average kinetic energy of the atoms or molecules of a body or substance, perceived as warmth or coldness. Measured in degrees Fahrenheit, Celsius, or Kelvin.

See: Maxim's full line of thermal management integrated circuits.

Temperature Comparator An integrated circuit with a digital output that indicates whether a measured temperature is above or below a predetermined threshold.
Temperature Compensated Crystal Oscillator See TCXO
Temperature Control See Thermal Management
Temperature Management See Thermal Management
Temperature Resistor See Thermistor
Temperature Sensor Temperature sensor that uses an external diode-connected transistor as the sensing element to measure temperatures external to the sensor (for example, on a circuit board or on the die of a CPU). Generally produces a digital output.
Temperature Shutdown See Thermal Shutdown
Temperature Switch A circuit that opens and closes a conductive path based on temperature.
Tesla Tesla (abbreviated T) is a measure of magnetic flux density (B-field), named for engineer and inventor Nikola Tesla.
TFT Thin-film transistor
THB Temperature/humidity bias
THD Total Harmonic Distortion (THD): A measure of signal distortion which assesses the energy that occurs on harmonics of the original signal. It is specified as a percentage of the signal amplitude.

As an example, if a 12kHz signal is applied to the input, THD would look at energy on the output occurring at 24kHz, 36kHz, 48kHz, etc. and compare it to the energy occurring at 12kHz.

THD+N Total Harmonic Distortion Plus Noise (THD+N) is the sum of the two most important distortion components. THD is the distortion that occurs on harmonics of the original signal -- it is correlated with the signal. Noise is the more random, uncorrelated distortion. THD+N is their sum.
Thermal Control See Thermal Management
Thermal Control Circuit Circuit to monitor and control the temperature of something. For example the integrated temperature controller in Intel's processors.
Thermal Management The use of various temperature monitoring devices and cooling methods, such as forced air flow, within a processor or FPGA-based system, to control overall temperature of ICs and internal cabinet temperatures.
Thermal Monitor The integrated thermal control system used in Intel's processor devices.
Thermal Shutdown Deactivating a circuit when a measured temperature is beyond a predetermined value.
Thermal Switch See Temperature Switch
THERMDA Thermal Diode Anode pin on AMD and Intel processors.
THERMDC Thermal Diode Cathode pin on AMD and Intel processors.
Thermistor A temperature-dependent resistor with a high temperature coefficient, usually composed of sintered semiconductor material.
Thermochron A Thermochron device measures and records (logs) temperature. (Thermochron is a trademark of Maxim Integrated.)
Thermochron i-Button See Thermochron
Thermochron iButton See Thermochron
Thermocouple A temperature sensor formed by the junction of two dissimilar metals. A thermocouple produces a voltage proportional to the difference in temperature between the hot junction and the lead wire (cold) junction.
thermoelectric cooler See TEC
Thermostat Circuit that indicates whether a measured temperature is above or below a particular temperature threshold or trip point. Used for thermal protection and simple temperature control systems.
THERMTRIP See THERMTRIP#
THERMTRIP# Pin name of the Thermal Trip digital output on Intel Pentium processors. The pin is asserted at a nominal die temperature of 135 degrees-C.
THERMTRIP_L Pin name of the thermal trip output pin of AMD processors. The pin is asserted at a nominal die temperature of 125°C.
Thin-QFN See TQFN
THINERGY MEC See Micro Energy Cell
Third Order Input Intercept Point See IIP3
Third Order Intercept Point See IIP3
Three-State A three-state, or Tri-State™, output has three electrical states: One, zero, and "Hi-Z," or "open." The hi-Z state is a high-impedance state in which the output is disconnected, leaving the signal open, to be driven by another device (or to be pulled up or down by a resistor provided to prevent an undefined state).

High-impedance schemes such as three-state are commonly used for a bus, in which several devices can be selected to drive the bus.

Tri-State™ is a trademark of National Semiconductor.

Through-Hole A method for mounting components on a printed circuit board (PCB) in which pins on the component are inserted into holes in the board and soldered in place.
TIA See Transimpedance Amplifier
TIM See Transient Intermodulation Distortion
Time Diversity In radio systems, Time Diversity spreads a signal across multiple channels by placing multiple versions of the signal in different time slots.
Time Division Multiple Access See TDMA
Time Division Multiplexing See TDM
Timing Distortion See Jitter
Tin Whiskers Tin whiskers (also called Sn whiskers or metal whiskers) are microscopic, conductive, hair-like crystals that emanate spontaneously from pure tin (especially electroplated tin) surfaces. Whiskers form primarily on elemental metals, but have also been found on alloys. Crystals can form in any environment. The actual mechanism for their formation is not well understood.

Tin-lead (SnPb) finishes prevent tin whiskers. Maxim offers a SnPb solution for customers requiring a non-RoHS finish. It is available for virtually all lead-free products.

Tin whiskers are not dendrites. Dendrites are fern-like and grow on the surface of the metal in an environment with moisture present. Tin whiskers tend to grow orthogonally from the surface.

See:

TINI
TINI® is Maxim's trademark for its family of highly integrated solutions for the consumer electronics market. The family includes ICs which integrate disparate functions to achieve advantages in board space. Examples include:
  • TINI Power SoCs integrate all the functional blocks needed to power applications and baseband processors, along with mixed-signal functions like audio, battery management, and touch-screen control. These Power SoCs allow mobile platform system designers to cut their analog footprint in half.
  • TINI Audio Codecs (MAX98089, MAX98095) combine multiple high-performance audio blocks with Maxim's proprietary FlexSound® processor. These audio codecs let designers overcome integration challenges in mobile products while delivering the best audio experience.
  • TINI Touch-Screen Controller SoCs (MAX11871) integrate the industry's highest SNR capacitive-touch analog front-end (AFE), a MAXQ® CPU for full backend processing, and a custom DSP coprocessor. The integration of a super-narrowband AFE provides breakthrough immunity to AC charger and LCD noise without any external components.
TINI is a registered trademark of Maxim Integrated
Note: Tiny Network Interface circuits are now called MxTNI.
TLA Three-Letter Acronym.
Total Harmonic Distortion See THD
Total Harmonic Distortion Plus Noise See THD+N
Totem Pole A standard CMOS output structure where a P-channel MOSFET is connected in series with an N-Channel MOSFET and the connection point between the two is the output. The P-FET sits on top of the N-FET like a "totem pole." Both gates are driven by the same signal. When the signal is low, the P-FET is on; when the signal is high, the N-FET is on. This creates a push-pull output using just two transistors.
TouchTone See DTMF
TQFN Thin version of the QFN package (the JEDEC "W" option) 0.8mm thick.
TQFP Thin quad flat pack
Transceiver A device that contains both a transmitter and receiver.

Common misspellings: Transciever, Tranceiver, Transeiver, Transiever, Tranciever, Transcever.

Examples:

Transconductance The gain of a transconductance amplifier (an amp in which a change in input voltage causes a linear change in output current). The basic gain of vacuum tubes and FETs is expressed as transconductance. It is represented with the symbol gm.

The term derives from "transfer conductance" and is measured in siemens (S), where 1 siemens = 1 ampere per volt. It was formerly measured as "mho" (ohm spelled backwards).

Transconductance Amplifier An amplifier that converts a voltage to a current. Also known by several other terms (see synonym list). One synonym is OTA, or operational transconductance amplifier, a term that marries the terms transconductance amplifier and operational amplifier.

The term derives from "transfer conductance" and is measured in siemens (S), where 1 siemens = 1 ampere per volt. It is represented with the symbol gm. The basic gain of vacuum tubes and FETs is expressed as transconductance.

See: Transimpedance Amplifier Buffers Current Transformer
Transducer Electronic Data Sheet A Transducer Electronic Data Sheet, or TEDS, is a method for plug-and-play sensor and transducer hook-up in which the sensor's calibration information is stored within the device and downloaded to the master controller when requested. A standardized TEDS specification is being developed by the IEEE, as IEEE P 1451.4.
Transfer Transfer refers to the amount of data transferred across a digital interface, exclusive of any extra bits used to encode the data.

The number of data transfers is less than the number of bits transmitted when encoded data has more bits than the raw data. As an example, a PCIe serial bus uses 10 bits to encode eight data bits. (Extra bit space may be used to encode a clock, error-detection redundancy, etc.)

Data rates are commonly expressed in transfers per second, gigatransfers per second (GT/s) and megatransfers per second (MT/s).

transfer rate See Transfer
Transformer An inductive electrical device for changing the voltage of alternating current.

A transformer consists of two magnetically coupled coils. Alternating current in one (called the "primary") creates a changing magnetic field which induces a current in the second coil (the "secondary"). A core made of iron or ferrite generally connects the two coils, but higher frequency devices can work without a ferrous core.

Transformers have two primary functions: Voltage transformation and isolation:

  • The voltage of the secondary can be higher or lower than the voltage that drives the primary and is determined by the ratio of turns of wire in the two coils.
  • Isolation refers to the fact that the coils are connected only by a magnetic field, so they can be independent of a common ground.

Primary applications are for power and for signal isolation / impedance transformation.

An autotransformer is a transformer with a single coil with intermediate "taps" to effect the changed outgoing voltages. They do not provide isolation.

Transformer capacity is rated in kilovolt-amps (KVA): The volts x amps / 1000.

Transient Intermodulation Distortion Transient intermodulation distortion, or TIM, occurs in amplifiers that employ negative feedback when signal delays make the amplifier incapable of correcting distortion when exposed to fast, transient signals.
Transient Voltage Suppressor See TVS
Transimpedance Amplifier An amplifier which converts a current to a voltage. It is a familiar component in fiber-communications modules.

The unit for transresistance is the ohm.

See: Transimpedance Amplifier Buffers Current Transformer
Transistor A basic solid-state control device which allows or disallows current flow between two terminals, based on the voltage or current delivered to a third terminal.

Usually built from silicon but can be constructed from other semiconductor materials. There are two major types: The FET (field-effect transistor) and the bipolar junction transistor (BJT).

The first transistor was invented in 1947 at Bell Labs by Michael John Bardeen, Walter Brattain and William Shockley.

Transistor Sensor See Remote Temperature Sensor
Transistor Temperature Sensor See Junction Diode Sensor
Transmission Control Protocol/Internet Protocol See TCP/IP
Transmission Gate See Analog Switch
Transmitter A circuit that accepts signals or data in and translates them into a form that can be sent across a medium (transmitted), usually over a distance. The medium can be wireless or wired.

Examples:

  • A radio transmitter that modulates the signal on a carrier and transmits it over the airwaves
  • An ultrasonic transducer that sends the signal over ultrasound frequencies
  • A line driver that drives a backplane
  • A circuit that drives an interface (e.g., USB, serial, LVDS)
  • A fiber optic device that emits light pulses
Transresistance Amplifier See Transimpedance Amplifier
trr See Reverse Recovery Time
TS 16949 TS 16949 is an ISO Technical Specification that aligns previous American (QS-9000), German (VDA6.1), French (EAQF) and Italian (AVSQ) automotive quality systems standards within the global automotive industry. Together with ISO 9001:2000, ISO/TS 16949:2002 specifies the quality system requirements for the design/development, production, installation and servicing of automotive related products.
TS-16949 See TS 16949
TSOC Thin small-outline C-lead
TSOP Thin small-outline package
TSSM Temperature sensor and system monitor
TSSOP Thin shrink small-outline package
TTC Temperature conversion sample time
TTFC Time remaining to full charge
TTIMD Two-tone intermodulation distortion
TTL Transistor-to-transistor logic
Tube Motor See Tubular Motor
Tubular Motor A tubular motor is an electric motor embedded in a cylindrical form factor. They are typically used for window shades and blinds, projection screens, awnings, roller doors, etc.
TUE Total unadjusted error
tuned circuit See Resonant Circuit
TV See Television
TVM Test vector monitor
TVS Transient Voltage Suppressor: Semiconductor device designed to protect a circuit from voltage and current transients. Typically implemented as a large silicon diode operating in avalanche mode to absorb large currents quickly.
Tweak Tweak (or sometimes, "tweek") means to make small adjustments to a system to improve its performance.
Twisted-Pair See Differential Signaling
Tx Transmit