"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",
"N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"

J1850. An automotive bus used for diagnostics and data sharing applications in vehicles. J1850 may use either a single or differential wire approach. [J1850 Bus Description]

JACK. A socket. A receptacle.

JACKET. The outer sheath which protects a cable

JITTER. Jitter is the difference [deviation] between the expected occurrence of a signal edge and the time the edge actually occurs [phase variation]. Jitter may also be expressed as the movement of a signal edge from its ideal position in time [the expected position]. Abrupt and unwanted variations of one or more signal characteristics, such as the interval between successive pulses, the amplitude of successive cycles, or the frequency or phase of successive cycles.

JTAG. Joint Test Action Group. IEEE Std 1149.1-1990, Test Access Port and Boundary-Scan Architecture (3) The JTAG interface is a serial bus with four signals: Test Clock (TCK), Test Mode Select (TMS), Test Data Input (TDI), and Test Data Output (TDO).
[JTAG Bus Description]