Skip to main content

ATE glossary of terms

This handy reference of commonly used terms will help you navigate and understand the complex language of the automated test equipment industry.

Silicon chip image

ATE – Automated test equipment

A test equipment system that is computer driven and able to run test programs to test the unit under test.


The ability of an instrument to automatically choose the optimum range of the instrument for the magnitude of the measurement being made.

AVO –Amps, volts and ohms

This term is often used to indicate a type of meter. It is a trade name and their major products were robust, quality, analogue multimeters.

BIST – Built-in self test

A facility contained within a circuit, module or unit that enables it to test itself. It will typically consist of some additional circuitry and software.

BIT – Built-in test

Another name for BIST.

BITE –Built-in test equipment

This refers to the circuitry or "equipment" that is built in to a unit of assembly to enable to undergo a self test.

CMRR – Common mode rejection ratio

It is a measure of the ability of a test instrument to reject interference that is common to both of its measurement input terminals. It is expressed in decibels and it is the ratio of the actual or common signal level appearing on the two input terminals together to the measured level.

Boundary scan

A test methodology that uses shift registers in the output connections of integrated circuits, one IC often is connected to the next. A data pattern is passed through the chain and the observed returned data stream affected by the circuit conditions gives an indication of any faults present. The system is defined under IEEE standard 1149.1 and is also often known as JTAG (Joint Test Action Group).

DMM – Digital multimeter

This a digital meter that is capable of making a variety of types of measurement. The basic measurements that are normally made include voltage, current (both AC and DC) as well as resistance. Many meters have a variety of other measurements that can be made and these may include frequency (normally not to a high degree of accuracy), capacitance, temperature, etc.

FATE - Functional automated test equipment

An automated test equipment that tests the operation of the UUT. This type of system is normally used in large scale electronics equipment manufacture and test.

FSD – Full scale deflection

This is the maximum calibrated reading for a meter.

Frequency counter

An instrument for measuring the frequency of a signal accurately. It operates by 'counting' the number of crossings of the signal that occur across a certain trigger level.

GPIB – General purpose interface bus

Originally known as HP-IB (Hewlett Packard Interface Bus) and also defined as IEEE 488, this bus is used for communicating between devices. One of its main uses is for automatic test applications where a computer is used to control a number of test instruments.


This is a form of meter that is capable of making a variety of measurements. It is normally applied to a meter that can make measurements of current, voltage and resistance, although digital versions available today may be capable of making a variety of measurements. Normally a multimeter is a small, portable and robust instrument.


A form of measuring instrument that displays waveforms of a screen, the horizontal axis being indicative of time, and the vertical providing the instantaneous amplitude at that given instant. An oscilloscope is an invaluable test tool for anyone testing or developing circuits in which there are repetitive waveforms that need to be viewed.

PPM – Parts per million

This is normally used to indicate the accuracy of an item. A component may be said to have an accuracy of 100 PPM. In this case its value is accurate to within 100 parts in a million or 0.01%.

Settling time

The time required after a change for a circuit or test instrument to reach its steady state.

UUT – Unit under test

This a term used in commercial production testing to define the target item that is being tested.


Contact Form

Get in touch with Vicor

Thank you for contacting us

You should receive a reply to your request within one business day.