Agilent Technologies 4284A, Operation Manual

Page: 175 / 460

Figure 6-4. Inductance Circuit Mode Selection
The following is a rule of th um b for selecting the circuit mo de
according to the imp edance of the inductor.
Belo w appro x. 10 : use series circuit mo de
Ab o v e appro x. 10 k : use parallel circuit mo de
Bet w een ab o v e v alues : follo w the man ufacturer's
recommendation
F or example, to measure a 1 mH inductor at the 1 kHz (imp edance
may b e appro ximately 6.3 ), L
s
-D or L
s
-Q function is suitable.
Signal Lev el
Most comp onen ts ha v e imp edance c haracteristics that are dep endent
on the applied signal lev el. So, the oscillator lev el setting should b e
set appropriate for the DUT.
Signal Lev el
Across The DUT
Figure 6-5 sho ws a simplied mo del of the 4284A and a DUT. The
signal lev el across the DUT dep ends on the oscillator lev el, the source
resistance of the 4284A, and the imp edance of the DUT, as follo ws.
j V
m
j =
j Z
x
j
j R
so
+ Z
x
j
2 j V
osc
j
j I
m
j =
j V
osc
j
j R
so
+ Z
x
j
Where, j V
osc
j : oscillator v oltage lev el of the 4284A,
R
so
: Source resister of the 4284A (= 100 ),
j V
m
j : Signal v oltage lev el applied on DUT,
j I
m
j : Signal curren t lev el o w ed in DUT,
j Z
x
j : Imp edance of DUT.
Measurement Procedure and Examples 6-7