C V P A R D ( R I P P L E A N D N O I S - Agilent Technologies E3646A/47A User Manual

Appendix Service Information
Constant Voltage (CV) Verifications
CV PARD (Ripple and Noise)
P e r i o d i c a n d r a n d o m d e v i a t i o n s ( P A R D ) i n t h e o u t p u t ( r i p p l e a n d n o i s e )
c o m b i n e t o p r o d u c e a r e s i d u a l a c v o l t a g e s u p e r i m p o s e d o n t h e d c o u t p u t
v o l t a g e . C V P A R D i s s p e c i f i e d a s t h e r m s o r p e a k - t o - p e a k o u t p u t v o l t a g e i n t h e
f r e q u e n c y r a n g e f r o m 2 0 H z t o 2 0 M H z .
• V R M S m e a s u r e m e n t t e c h n i q u e s :
W h e n m e a s u r i n g V r m s r i p p l e a n d n o i s e , t h e m o n i t o r i n g d e v i c e s h o u l d b e
p l u g g e d i n t o t h e f r o n t o f t h e t e r m i n a l s a t ( A ) i n F i g u r e A - 2 . U s e t h e B N C
( F e m a l e ) r e c e p t a c l e a n d t h e c a b l e ( B N C t o B N C ) t o c o n n e c t t h e m o n i t o r d e v i c e
t o t h e p o w e r s u p p l y . T o r e d u c e t h e m e a s u r e m e n t e r r o r c a u s e d b y c o m m o n
m o d e n o i s e , i t i s r e c o m m e n d e d t o t w i s t t h e c o n n e c t i o n w i r e b e t w e e n t h e B N C
r e c e p t a c l e a n d t h e o u t p u t t e r m i n a l s . T h e l o a d r e s i s t o r i s c o n n e c t e d t o t h e
t e r m i n a l a t ( B ) i n F i g u r e A - 2 . T w i s t e d l e a d s b e t w e e n t h e l o a d r e s i s t o r a n d t h e
p o w e r s u p p l y h e l p s r e d u c e n o i s e p i c k u p f o r t h e s e m e a s u r e m e n t s .
Load Resistor
(Front Panel Connections)
N o t e :
For better measurement result, it is recommended to make the connection between
the BNC receptacle and the output terminals shorter as much as possible, and to use
the recommended split ferrites with the cable (BNC to BNC) as shown above.
182
RMS voltmeter
Input
Load Resistor
(Rear Panel Connections)
RMS voltmeter
Input
BNC
Receptacle
BNC Cable
Split Ferrites*