advantest corporation TR5821, Руководство по эксплуатации

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5 -3 . M e a s u re m e n t A c c u ra c y
5 -3 -1 . F r e q u e n c y M e a s u r e m e n t ( F R E Q . A , C )
T h e m e a s u r e m e n t m e t h o d e m p lo y e d h e r e c o u n ts t h e n u m b e r o f r e p e titio n s
o f th e sig n al to b e m e a s u re d p e r u n it tim e a n d d is p la y s it as th e fr e q u e n c y
( c /s = H z ). A s a c o n s e q u e n c e , t h e q u a n t iz a ti o n e r r o r o f ±1 c o u n t as s h o w n
b e lo w o c c u rs in t h e le a s t s ig n if ic a n t d ig it.
Signal to be measured
M easurem ent gate A
M easurem ent gate B
C o u n tin g b y gate A
C o u n tin g b y gate B
T h is is e x p re s s e d a s fo llo w s :
f * T = ± L S D o f t h e d is p la y
I X ^ 1 G
w h e r e : f x = M e a s u re d f r e q u e n c y (H z )
T
g
= G a te tim e (s )
T h e a c c u ra c ie s fo r d if f e r e n t f r e q u e n c ie s a n d g ate tim e s are s h o w n b e lo w .
F R E Q . C u ses a d iv id e - b y - tw e n ty p r e s c a le r ; th e a c c u ra c y is r e d u c e d b y 1
d ig it f o r th e sa m e g a te tim e .
I I ....... I I I I I I I I I
ft
ta
- L
il- TB --L
1 1 1 1 I I ......... II
1 1 1 1 1 1 1 1 11 1 1 1
T
a
-TB
- 14 cou nts
- 1 3 co u n ts
5-7