Time Ze Ro Ca L I B Ra T I O - HP 5363B Operating And Service Manual

M od e l 5363 B
S e rv i c e
I NPUT
VO LTAG E
T R I G G E R V O LTA G E
V
O FFSE T O LTAGE
Ti me Z e ro Cali b ration
8 -7 7 .
T h e re is p re s e n t in any a p p l i c a t i o n c o n f i g u ra t i o n . a s m a l l t i me d e l a y c a u se d b y t h e
8-78.
T i m e I n te rva l P r o b e s , t h e e l e c t ro n i c c o u n te r a n d t h e c o n n e c t i n g c a b l e s . T h e T i m e Z e r o
Ca l i b ra t i o n r o u t i n e p rovi d e s a m e t h o d of ba l a n c i n g o u t t h i s d e l a y . I n s e rt i n g t h e p r o b e s i n t h e
ca l i b ra t i o n j a c k s a n d p ress i ng t h e f ro n t p a n e l T I M E Z E R O s w i t c h i nj ec ts a s t rea m of h i g h ­
speed p u l se s i n to b o t h STA R T a n d S T O P c h a n n e l s s i m u l ta n e o u s l y . A c o n t r o l p o t o n t h e f ro n t
pa n e l c o n t r o l s t h e a d j u sta b l e d e l a y i n t h e S T O P c h a n n e l B y i nj e c t i n g p u l ses a n d adj u st i n g t h e
STO P c h a n n e l d e l a y. t h e system g e n e rated t i m e d e l a y c a n b e m a t c h e d a n d effec t i ve l y
red uced t o z e ro . A f i xed d e l a y l i n e i s s w i t c h e d i n to t h e STO P c h a n n e l to a l l o w o p e ra t i o n w i t h
c o u n te rs w h ose m i n i m u m ti m e i n te rva l reso l u t i o n e xceed s 1 - n a n osec o n d . T h i s f i xed d e l a y .
h o we ve r. m u st b e s u b t racted f r o m t h e c o u n te r d i s p l a y b y t h e o p e ra t o r .
8 - 1 8
+ 1 5V
[OCCU R S W H E N : ( I NPUT VO LTAGE )
( T R I GG E R VO LTAG E) + (OF FSET VO LTAG E )
- 1 5V
=
Level set o n t h u m bwhee l switches, o r v i a H P- I B , from Reference D A C A2.
O.OOV
==
d u r i n g C a l i brati o n .
[ V(gs2)-V(gS1 ) ) V
==
+ ( co m parator offset )
V
+ ( co m mon-base l oad offset ) .
< <
-75 m V offset voltage
Figure 8 - 4 . Simplified 53638 Input Circuit
T R I G G E R
( T R I GG E R VO LTAG E ) + ( O F FSET VO LTAG E ) ]
+75 m V
�