7 active (real) power register, 8 rms current & voltage registers ( i, 9 epsilon register ( e ) – Cirrus Logic CS5463 User Manual
Page 28: Cs5463, 7 active (real) power register ( p, 9 epsilon register
CS5463
28
DS678F3
6.1.6 Instantaneous Current, Voltage, and Power Registers ( I , V , P )
Address: 7 (Instantaneous Current); 8 (Instantaneous Voltage); 9 (Instantaneous Power)
I and V contain the instantaneous measured values for current and voltage, respectively. The instantaneous
voltage and current samples are multiplied to obtain Instantaneous Power (P). The value is represented in two's
complement notation and in the range of -1.0
I, V, P 1.0, with the binary point to the right of the MSB.
6.1.7 Active (Real) Power Register ( P
Active
)
Address: 10 (Active Power)
The instantaneous power is averaged over each computation cycle (N conversions) to compute Active Power
(P
Active
). The value will be within in the range of -1.0
P
Active
1.0. The value is represented in two's complement
notation, with the binary point to the right of the MSB.
6.1.8 RMS Current & Voltage Registers ( I
RMS
, V
RMS
)
Address: 11 (I
RMS
); 12 (V
RMS
)
I
RMS
and V
RMS
contain the Root Mean Square (RMS) values of I and V, calculated each computation cycle. The
value is represented in unsigned binary notation and in the range of 0.0
I
RMS
, V
RMS
1.0, with the binary point
to the left of the MSB.
6.1.9 Epsilon Register (
)
Address: 13
Default = 0x01999A = 0.0125 sec
Epsilon (
) is the ratio of the input line frequency to the sample frequency of the ADC (See Section 5.4
on page 16). Epsilon is either written to the register, or measured during conversions. The
value is represented in two's complement notation and in the range of -1.0
1.0, with the binary point to the
right of the MSB. Negative values have no significance.
MSB
LSB
-(2
0
)
2
-1
2
-2
2
-3
2
-4
2
-5
2
-6
2
-7
.....
2
-17
2
-18
2
-19
2
-20
2
-21
2
-22
2
-23
MSB
LSB
-(2
0
)
2
-1
2
-2
2
-3
2
-4
2
-5
2
-6
2
-7
.....
2
-17
2
-18
2
-19
2
-20
2
-21
2
-22
2
-23
MSB
LSB
2
-1
2
-2
2
-3
2
-4
2
-5
2
-6
2
-7
2
-8
.....
2
-18
2
-19
2
-20
2
-21
2
-22
2
-23
2
-24
MSB
LSB
-(2
0
)
2
-1
2
-2
2
-3
2
-4
2
-5
2
-6
2
-7
.....
2
-17
2
-18
2
-19
2
-20
2
-21
2
-22
2
-23