HP 5383A

F
ig ure 4-4 .
10 5/ Ηz
L ea d i n g Ze r o B la nk i n g F u n ctio n
M o d el 5383 Α
T h eory
of O pe r atio n
DIS PL
AY
DIGIT
S5
DS1
D ur i ng
sca n time S7, t
h
e RB latc h is agai
n p
r eset, dr
iving
t
h
e ou t pu t of N
A
N DGAT E U 20
low . As
α
r es u
lt,
t he RB I
gate
ou
t p ut is fo
r
ced
h ig h ; d efeati n g
t
he RB I sig n
al
a nd
allowi n g t he un it's H z ze r o d igit, t h
e
d ecimal p
oi
n t, a nd t he 0 .1 H z ze r o d igit to b e
d is p lay (i .e .,

0 .

0

) .
S4
DS2
CO N DITIO N S :

ΝΟ INPUT SIG NA L
GAT
E ΤΙΜΕ =
10s/Hz
SCAN TIME
s3 S2
I
S1 s
DS3
DS4 DS5
DS6
S9
DS7
S7 , Ι S6
DS9
D ur i ng sca n time
57,
R i pp le B la nk i n g (RB) L atc h A1 U 23 is p r eset . P i n
5 goes
h ig h ;
dr ivi ng t he o u t pu t of e n able d N A ND GAT E A1 U 20 low . T he low ou t pu t of U 20 fo r ces
t h e R i pp le B lan k i ng I npu t ( RB I) Gate outp u t h ig h . T he d isplay digits a r e not eval u ate d
a nd no bla nk ing occ ur s at t h is time .

,
T h e
low S5
signal
fo
r ces N AN
D GAT E A1 U 20
h ig
h .
Th
is
h ig h
dr ives enabled RB I gate
U 24
low,
allowi n g t he d is p lay d igits
to b
e
eval
u
ate
d .
Ze
r o
is
se n se
d ,
ca u
si
ng t
h e most
sig n ifica n t digit to b e bla nked dur i n g S5 a nd t h e R i pp le B la nk ing O u tp u t ( RB
O)
to
go low .
L ow RB O clea r s t h e RB latc h . T h e r es u lti n g low o u tp u t k ee p s N A ND GAT E U 20-8 h ig h ;
w h
ic h in t urn keeps t he RB I signal active (low) . Si n ce t h e r e is no i npu t signal to t he
co un te r , eac h d igit eval u ate d is ze r o, causing RB O to remain low .
(CA NT
4-7
FRE
Q
UEN CY
V A LUE
10' τ
MHz
UN IT'S
MHz
100' τ
kHz
10'
τ
kHz
UN
IT'S
kHz
100's
Hz
10's
HZ
'DEAD'
'TIME'
UN IT'S
Hz
0 .1
ι
SIGNIFICANT
DEC . ί
Ι
( M OST
DIGIT)
POINT
ι
SIG N I F
Ι
DIGIT)
Ι
ι
RB
K
D
L ATC H ι '
Α 1 U 23-5 Ί
Ι ~~
ι
10 τ D EFE AT ι
(
NAN D) -
GAT E
Α 1 U 20-8 Ι Ι
RB I Ι ι
Al U24-6
(ι , Ι1 . Ι1
ι
ι ΙΙ , Ι ~ ι Ι 1 ~ Γ 1 Ιι . ΙΙ , ~ Ι
R BO
Ι
Α2 υ 1-4
ιΙι ,~1 Ι , Ιι , ΙΙ ~~ Ιι . Ιι , Ιι ,,
. . . .
~Ι ~ Ι, Ιι , ι ~ h Ιι ~1~1~ Ι 1~ ι ~ h
Ι