Glossary Terms and Definitions Beginning with the Letter J

J See Joule
JALT Jitter attentuator limit trip
JBOD Just a Bunch of Disks: An array of hard disks without a controller.
JEDEC Joint Electron Device Engineering Council
JFET A JFET, or junction field-effect transistor, or JUGFET, is a FET in which the gate is created by reverse-biased junction (as opposed to the MOSFET which creates a junction via a field generated by conductive gate, separated from the gate region by a thin insulator).

For example: A p-channel JFET would consist of a bar of p-type silicon with the "drain" at one end and the "source" at the other. Between these two terminals is some n-type material connected to a "gate". A positive voltage applied to the gate creates a "depletion field" which restricts current flow between the source and drain.

JITT Just-in-time tester
Jitter The slight movement of a transmission signal in time or phase that can introduce errors and loss of synchronization. More jitter will be encountered with longer cables, cables with higher attenuation, and signals at higher data rates. Also, called phase jitter, timing distortion, or intersymbol interference.

For more information and illustrations, see:

Joule Joule (abbreviated J): A measurement of energy or work. In mechanical systems, it's the a force of one newton, moving an object a distance of one meter.

In electronics, it's the same amount of energy, in electrical units. One joule is one watt of power, applied for one second (a watt-second); or a coulomb of electrical charge raised to a potential of one volt.

JPEG Joint Photography Experts Group; more commonly, files that are compressed using the JPEG standard.
Junction Diode Sensor The use of a PN junction on a silicon die for determining die temperature.
Junction FET See JFET
Junction Temp Sensor See Remote Temperature Sensor
Junction Temperature Sensor See Remote Temperature Sensor
Just A Bunch of Disks See JBOD
JVM Java virtual machine.