Maxim Integrated 71M6533-DB - Manual (Page 36)

71M6533- DB Demo Board User’s Manual
Page: 36 of 75 ` REV 3
From the voltage measurement, we determine that
1. 1
 
V XV
E A
We use the other two measurements to determine

S
and A
XI
.
2. 1 ) cos( 1
) 0 cos(
) 0 cos(
0
  


S XI XV
S XI XV A A
IV
A A IV
E


2a.
) cos(
1
0
S
XI XV
E
A A



3. 1
) 60 cos(
) 60 cos(
1
) 60 cos(
) 60 cos(
60


 


S
XI XV
S XI XV A A
IV
A A IV
E
 
3a.
 
1
) 60 cos(
) sin( ) 60 sin( ) cos( ) 60 cos(
60



S S XI XV
A A
E
 
1 ) sin( ) 60 tan( ) cos(
  
S XI XV S XI XV
A A A A
 
Combining 2a and 3a:
4. ) tan( ) 60 tan( ) 1 (
0 0 60 S
E E E
   
5.
) 60 tan( ) 1 (
) tan(
0
0 60



E
E E
S

6. 







 
) 60 tan( ) 1 (
tan
0
0 60 1
E
E E
S

and from 2a:
7.
) cos(
1
0
S XV
XI
A
E
A



Now that we know the A
XV
, A
XI
, and

S
errors, we calculate the new calibration voltage gain coefficient from the
previous ones:
XV
NEW
A
V CAL
V CAL
_
_

We calculate PHADJ from

S
, the desired phase lag:
 
  





   
   

 
 
) 2 cos( ) 2 1 ( 1 ) tan( ) 2 sin( ) 2 1 (
) 2 cos( ) 2 1 ( 2 ) 2 1 ( 1 ) tan(
2
0
9
0
9
0
9 2 9
20
T f T f
T f
PHADJ
S
S
  
 