71M6521FE-IGT/F Maxim Integrated Products, 71M6521FE-IGT/F Datasheet - Page 86

• Manufacturer Part Number: 71M6521FE-IGT/F
• Description: IC ENERGY METER 32K FLASH 64LQFP
• Manufacturer: Maxim Integrated Products

Specifications of 71M6521FE-IGT/F

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The table below describes each transfer variable for fundamental energy measurement. All variables are signed 32
bit integers. Accumulated variables such as WSUM are internally scaled so they have at least 2x margin before
overflow when the integration time is 1 second. Additionally, the hardware will not permit output values to ‘fold back’
upon overflow.
WxSUM_X is the Wh value accumulated for element ‘X’ in the last accumulation interval and can be computed based
on the specified LSB value.
For example with VMAX = 600V and IMAX = 208A, LSB (for WxSUM_X ) is 0.08356 µWh.
The Frequency measurement is computed using the Frequency locked loop for the selected phase.
IxSQSUM_X and VxSQSUM are the squared current and voltage samples acquired during the last accumulation
interval. INSQSUM_X can be used for computing the neutral current.
The RMS values can be computed by the MPU from the squared current and voltage samples as follows:
MAINEDGE_X is 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 chip temperature or to implement temperature compensation.
Page: 86 of 107
Ix
Address
Address
0x76
0x72
0x75
0x71
RMS
0x7D
0x79
0x77
0x73
0x78
0x74
0x7E
CE
CE
=
IxSQSUM
VAR0SUM_X
VAR1SUM_X
WSUM_ACCUM
VSUM_ACCUM
W0SUM_X
W1SUM_X
V0SQSUM_X
V1SQSUM_X
I0SQSUM_X
I1SQSUM_X
Name
FREQ_X
Name
N
⋅
LSB
ACC
⋅
3600
Instantaneous Energy Measurement Variables
Fundamental Energy Measurement Variables
⋅
Description
The sum of Watt samples from each wattmeter element (In_8 is the gain
configured by IA_SHUNT or IB_SHUNT).
LSB = 6.6952*10
The sum of VAR samples from each wattmeter element (In_8 is the gain
configured by IA_SHUNT or IB_SHUNT).
LSB = 6.6952*10
F
Description
Fundamental frequency. LSB
The sum of squared current samples from each element.
LSB = 6.6952*10
The sum of squared voltage samples from each element.
LSB= 6.6952*10
These are roll-over accumulators for WPULSE and VPULSE
respectively.
S
Other Measurement Parameters
-13
-13
Vx
-13
-13
VMAX IMAX / In_8 Wh.
VMAX IMAX / In_8 Wh.
RMS
VMAX
IMAX
=
2
2
VxSQSUM
V
/ In_8
2
h
≡
2
2
F
A
32
S
2
h
≈
N
⋅
. 0
LSB
ACC
587
⋅
71M6521DE/DH/FE Data Sheet
3600
⋅
10
−
⋅
6
F
Hz
S
Rev 2