CDB5463U Cirrus Logic Inc, CDB5463U Datasheet - Page 15

• Manufacturer Part Number: CDB5463U
• Description: BOARD EVAL & SOFTWARE CS5463 ADC
• Manufacturer: Cirrus Logic Inc
• Type: A/Dr

Specifications of CDB5463U

• Main Purpose: Power Management, Energy/Power Meter
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: CS5463
• Primary Attributes: 1-Phase, Energy-to-Frequency Output
• Secondary Attributes: GUI, USB, SPI Interfaces
• Product: Data Conversion Development Tools
• Maximum Clock Frequency: 4 MHz
• Interface Type: USB
• Supply Voltage (max): 5 V
• Supply Voltage (min): 3.3 V
• For Use With/related Products: CS5463
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant
• Other names: 598-1553

provides a pulse output that is proportional to the reac-
tive power or apparent power. Output E3 can also be set
to display the sign of the voltage applied to the voltage
channel or the PFMON comparator output.
The apparent power (S) is the combination of the active
power and reactive power, without reference to an im-
pedance phase angle, and is calculated by the CS5463
using the following formula:
Power Factor (PF) is the active power (P
by the apparent power (S)
The sign of the power factor is determined by the active
power.
The CS5463 calculates the reactive power, Q
ing trigonometric identities, giving the formula
Average reactive power, Q
ing the voltage multiplied by the current with a 90° phase
shift difference between them. The 90° phase shift is re-
alized by applying an IIR digital filter in the voltage chan-
nel to obtain quadrature voltage (see Figure 3). This
filter will give exactly -90° phase shift across all frequen-
cies, and utilizes epsilon (
line frequency.
The instantaneous quadrature voltage (V
(I) samples are multiplied to obtain the instantaneous
DS678F2
V *
I *
Q *
P *
+
Q
S
+
P off *
Trig
Σ
PF
=
V
=
=
RMS
PulseRate *
ε
X
X
Avg
) to achieve unity gain at the
P
----------------- -
S
Active
×
S
2
, is generated by averag-
–
Σ
Σ
I
RMS
N
N
P
Active
2
X
÷
÷
Figure 4. Power Calculation Flow.
Σ
Σ
N
N
N
N
Q
Active
Energy-to-pulse
) and current
Trig
÷
÷
) divided
√
√
N
N
utiliz-
+
+
V
I
ACoff
ACoff
Σ
Σ
E1
+
+
P
*
*
Q
ACTIVE
AVG
E2
*
X
quadrature power (Q). The product is then averaged
over N conversions, utilizing the formula
Fundamental active (P
culated by performing a discrete Fourier transform
(DFT) at the relevant frequency on the instantaneous
voltage (V) and current (I). Epsilon is used to set the fre-
quency of the internal sine (imaginary component) and
cosine (real component) waveform generator. The har-
monic active power (P
fundamental active power (P
(P
The peak current (I
the instantaneous current and voltage, respectively,
with the greatest magnitude detected during the last
computation cycle. Active, apparent, reactive, and fun-
damental power are updated every computation cycle.
4.4 Linearity Performance
The linearity of the V
power-factor power measurements (before calibration)
will be within ±0.1% of reading over the ranges speci-
fied, with respect to the input voltage levels required to
cause full-scale readings in the I
ters. Refer to
Until the CS5463 is calibrated, the accuracy of the
CS5463 (with respect to a reference line-voltage and
line-current level on the power mains) is not guaranteed
to within ±0.1%. (See Section 7.
page 37.) The accuracy of the internal calculations can
often be improved by selecting a value for the Cycle
Count Register that will cause the time duration of one
computation cycle to be equal to (or very close to) a
whole number of power-line cycles (and N must be
greater than or equal to 4000).
*
Active
V
E3
I
RMS
RMS
*
*
).
Inverse
X
Accuracy Specifications
S *
Q
X
X
Avg
peak
* DENOTES REGISTER NAME.
H
RMS
PF *
F
=
) is calculated by subtracting the
+
) and reactive (Q
) and peak voltage (V
------------------------ -
Σ
, I
-
n
∑
N
=
N
RMS
1
F
Q
) from the active power
√
n
, active, reactive, and
System Calibration
RMS
on page 7.
Q
and V
TRIG
F
*
) power is cal-
CS5463
RMS
peak
regis-
) are
on
15