Page 330 - Electrical Engineering Dictionary

Gray code
decimal digit 0 1 2 3 4 5
Gray code 000 001 011 010 110 111

white with other gray levels in between these GRIN optics See graded index optics.
extremes.
grip a twisted wire tie which secures a
grayscale See gray scale. wire to an insulator or other fixture.

Green book See IEEE Color Books.
grip teeth a set of jaws which secures a
wire to a hoist or come-a-long cf so that it can
Green’s function the function that satis-
be pulled into place.
fies a given differential equation having as
source term a Dirac delta function. See delta
gripple See gain ripple.
function.
Green’s theorems consider a closed, reg- grooved media on an optical disk, the
ular, surface S bounding a volume V where embossment of the disk surface with grooves
the two scalar functions φ and ψ, continuous such that the disk tracks are either the grooves
together with their first and second deriva- themselvesortheregionsbetweenthegroves.
tives throughout V and on the surface S, are
defined. Green’s first identity states ground (1) an earth-connected electrical
conducting connection that may be designed
Z Z
2
∇ψ ·∇φdV + ψ∇ φdV = or non-intentionally created.
V V (2) the electrical “zero” state, used as the
Z
∂φ
ψ dS reference voltage in computer systems.
S ∂n
while Green’s second identity takes the form ground bounce a transient variation in the
potential of the ground terminal of a logic de-
Z

2
2
ψ∇ φ − φ∇ ψ dV vice caused by variations in the supply cur-
V rent acting on the ground impedance of the
Z Z
∂φ ∂ψ circuit as seen by the device. Usually caused
= ψ dS − φ dS
S ∂n S ∂n by simultaneous turnon of the pullup and
pulldown sections of totem-pole outputs.
whichisfrequentlyreferredtoasGreen’sthe-
orem.
ground bounce noise ground bounce oc-
grey level See gray level. curs when a large number of semiconduc-
tor circuit components are mounted on a
grey scale See gray scale. common semiconductor chip substrate, so
that they are imperfectly insulated from each
grid refers to the regular array of vertical other. In normal operation the substrate
and horizontal wires used for interconnecting should act as an insulator; however, during
the chip. certain unusual fluctuations in signal levels,
the systems power and ground connections
grid array a technique for combining the can experience fluctuations, which affect the
output of amplifiers or oscillators in space performance of each component in a ran-
by using a two-dimensional spatial array of dom way that has the characteristics of noise,
elements placed on a uniformly spaced grid. much like capacitive coupling.

c
2000 by CRC Press LLC