71M6531D_10 Datasheet, PDF (93/120 Pages) Teridian Semiconductor Corporation – Energy Meter IC

FDS 6531/6532 005
Data Sheet 71M6531D/F-71M6532D/F
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I1SQSUM_X
LSB_I = 6.6952*10^-13 IMAX² / In_8² A²h
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V0SQSUM_X
V1SQSUM_X
The sum of squared voltage samples from each element.
LSB_V= 6.6952*10^-13 VMAX² V²h
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0x46
WSUM_ACCUM These registers contain roll-over accumulators for WPULSE and
VSUM_ACCUM ^{VPULSE respectively.}
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0x48
SUM3_ACCUM These registers contain roll-over accumulators for pulse outputs
SUM4_ACCUM ^{XPULSE and YPULSE respectively.}
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0x9A
I0SQRES_X
I1SQRES_X
These registers hold residual current measurements with double-
precision accuracy. The exact current ISQn is:
ISQn = InSQSUM_X + 2³² * InSQRES_X
The RMS values can be computed by the MPU from the squared current and voltage samples as follows:
Ix_RMS =
IxSQSUM ⋅ LSB_I ⋅ 3600 ⋅ F_S
N _ACC
Vx_RMS =
VxSQSUM ⋅ LSB_V ⋅ 3600 ⋅ F_S
N _ACC
Other Measurement Parameters
Table 63 describes the CE measurement parameters listed below:
• MAINEDGE_X: Useful for implementing a real-time clock based on the input AC signal. MAINEDGE_X
is the number of half-cycles accounted for in the last accumulated interval for the AC signal.
• TEMP_RAW: May be used by the MPU to monitor the chip temperature or to implement temperature
compensation.
• GAIN_ADJ: A scaling factor for measurements based on the temperature. GAIN_ADJ can be controlled
by the MPU for temperature compensation.
• VBAT_SUM_X: This result can be used to calculate the measured battery voltage (VBAT).
CE
Address
0x83
0x81
0x9D
0x40
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Table 63: Useful CE Measurement Parameters
Name
Default
Description
MAINEDGE_X
TEMP_RAW_X
TEMP_X
GAIN_ADJ
VBAT_SUM_X
N/A
N/A
N/A
16384
N/A
The number of zero crossings of the voltage selected with
FREQSELn in the previous accumulation interval. Zero crossings
are either direction and are debounced.
The filtered, un-scaled reading from the temperature sensor.
This register contains the difference between the die temperature
and the reference/calibration temperature as established in the
TEMP_NOM register, measured in 0.1°C.
Scales all voltage and current inputs. A value of 16384 provides
unity gain. This register is used by the CE or by the MPU to
implement temperature compensation.
Output of the battery measurement. This value is equivalent to
twice the measured ADC value.
4.3.8 Pulse Generation
Table 64 describes the CE pulse generation parameters WRATE, APULSEW, APULSER, APULSE2 and
APULSE3.
WRATE controls the number of pulses that are generated per measured Wh and VARh quantities. The lower
WRATE is the slower the pulse rate for measured energy quantity. The metering constant Kh is derived from
WRATE as the amount of energy measured for each pulse. That is, if Kh = 1 Wh/pulse, a power applied
to the meter of 120 V and 30 A (3,600 W) results in one pulse per second. If the load is 240 V at 150 A
(36,000 W), ten pulses per second will be generated.
The maximum pulse rate is 7.5 kHz for APULSEW and APULSER and 1.2 kHz for APULSE2 and APULSE3.
v1.3
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