78M6612-IMR/F Maxim Integrated Products, 78M6612-IMR/F Datasheet - Page 86

• Manufacturer Part Number: 78M6612-IMR/F
• Description: IC POWER MEASUREMENT AC 68-QFN
• Manufacturer: Maxim Integrated Products

Specifications of 78M6612-IMR/F

• Mounting Style: SMD/SMT
• Package / Case: QFN-68
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

78M6612 Data Sheet
4.4.7.1 Fundamental Energy Measurement Variables
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 = 52A, LSB (for WxSUM_X) is 0.005222
4.4.7.2 Instantaneous Energy Measurement Variables
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:
86
Ix
Address
Address
RMS
0x7A
0x7B
0x7C
0x72
0x78
0x79
0x18
0x74
0x75
0x76
0x77
CE
CE
=
IxSQSUM
WSUM_ACCUM
VAR1SUM_X
VAR2SUM_X
V1SQSUM_X
V2SQSUM_X
V3SQSUM_X
I1SQSUM_X
I2SQSUM_X
W1SUM_X
W2SUM_X
FREQ_X
Name
Name
N
⋅
LSB
ACC
⋅
3600
⋅
Description
The sum of Watt samples from each measurement element (In_8 is the
gain configured by IA_SHUNT or IB_SHUNT).
LSB = 1.67380 *10
The sum of VAR samples from each measurement element (In_8 is the
gain configured by IA_SHUNT or IB_SHUNT).
LSB = 1.67380 *10
F
Description
Fundamental frequency. LSB
The sum of squared current samples from each element.
LSB = 4.1845*10
The sum of squared voltage samples from each element.
LSB= 6.6952 * 10
The sum of squared voltage difference samples (V1-V2) between the
elements.
LSB= 6.6952 * 10
This is the roll-over accumulator for WPULSE.
S
Vx
RMS
-14
-13
-13
-13
-13
=
IMAX
VMAX
VMAX
VMAX * IMAX / In_8 Wh.
VMAX * IMAX / In_8 Wh.
VxSQSUM
2
2
2
A
V
V
2
h
2
2
h
h
≡
2
F
N
32
⋅
S
LSB
ACC
≈
. 0
⋅
3600
587
⋅
⋅
10
F
µ
S
Wh.
−
6
Hz
DS_6612_001
Rev. 1.2