MCP3906 Microchip Technology, MCP3906 Datasheet - Page 19

• Manufacturer Part Number: MCP3906
• Description: (MCP3905 / MCP3906) Energy-Metering ICs
• Manufacturer: Microchip Technology

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4.7
The thresholds for the accumulated energy are
different for F
ent transfer functions). The F
frequencies are quite low in order to allow superior
integration time (see Section 4.6 “Low-Pass Filter
and DTF Converter”). The F
can be calculated with the following equation:
EQUATION 4-1:
TABLE 4-3:
© 2009 Microchip Technology Inc.
Where:
V
REF
F1
0
0
1
1
F
V
V
G = the PGA gain on Channel 0
C
0
1
F
= the RMS differential voltage on Channel 0
= the RMS differential voltage on Channel 1
= the frequency constant selected
= the voltage reference
F
Frequencies
OUT
OUT0/1
(current channel)
OUT0/1
(
F0
Hz
0
1
0
1
)
OUTPUT FREQUENCY CONSTANT FC FOR FOUT0/1 (V
and HF
=
and HF
F
OUTPUT EQUATION
8.06
---------------------------------------------------------- -
OUT
MCLK/2
MCLK/2
MCLK/2
MCLK/2
F
×
C
OUT
OUT
FREQUENCY
V
(
OUT0/1
(Hz)
0
V
OUT0/1
×
REF
(i.e., they have differ-
21
20
19
18
V
Output
1
)
×
2
output frequency
G F
allowed output
×
(MCLK = 3.58 MHz)
C
F
13.66
C
1.71
3.41
6.83
(Hz)
For a given DC input V, the DC and RMS values are
equivalent. For a given AC input signal with peak-to-
peak amplitude of V, the equivalent RMS value is V/
sqrt(2), assuming purely sinusoidal signals. Note that
since the active (real) power is the product of two RMS
inputs, the output frequencies of an AC signal is half
that of the DC equivalent signal, again assuming purely
sinusoidal AC signals. The constant F
F
F
settings.
OUT0
OUT0/1
F
OUT
with Full-Scale
and F
output frequencies for the different logic
Frequency (Hz)
DC Inputs
0.74
1.48
2.96
5.93
OUT1
digital settings.
REF
MCP3905/06
= 2.4V)
F
OUT
with Full-Scale
Frequency (Hz)
AC Inputs
DS21948E-page 19
C
Table 4-3
depends on the
0.37
0.74
1.48
2.96
shows