71m6511h-igtr Maxim Integrated Products, Inc., 71m6511h-igtr Datasheet - Page 68

• Manufacturer Part Number: 71m6511h-igtr
• Description: Single-phase Energy Meter Ic
• Manufacturer: Maxim Integrated Products, Inc.

Instantaneous Power Measurement Variables
The FREQSEL Register selects the input phase used for frequency measurement and for the MAIN_EDGE counter. The
frequency measurement is implemented using the frequency locked loop of the CE 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 per the formulae:
Note: FS = 2520.6Hz (MUX_DIV = 1) or 3276.8Hz (MUX_DIV = 2)
Other Measurement Parameters
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 of the phase specified in the FREQSEL register.
Page: 68 of 95
Ix
Address
Address
RMS
CE
CE
4A
4B
4C
4D
4E
4F
33
41
50
52
53
55
=
IxSQSUM
MAINEDGE_X
V0SQSUM_X
RESERVED
RESERVED
I0SQSUM_X
I1SQSUM_X
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
FREQ_X
Name
Name
N
⋅
LSB
ACC
⋅
3600
Description
The number of edge crossings of the selected voltage in the previous
accumulation interval. Edge crossings are either direction and are de-
bounced.
Description
Fundamental frequency.
or
The sum of squared current samples from each element.
LSB = 6.6952*10
LSB = 5.1501*10
The sum of squared voltage samples from each element.
LSB= 6.6952*10
LSB = 5.1501*10
© 2005-2007 TERIDIAN Semiconductor Corporation
LSB
⋅
F
2
F
S
32
S
≡
≈
2
F
32
. 0
S
Vx
763
≈
RMS
. 0
-13
⋅
-13
-13
-13
587
10
=
VMAX
IMAX
IMAX
VMAX
−
6
⋅
10
Hz for MUX_DIV = 2
VxSQSUM
2
2
2
−
2
/ In_8
/ In_8
6
V
V
Hz for MUX_DIV = 1
2
2
h (for MUX_DIV = 1)
h (for MUX_DIV = 2)
Single-Phase Energy Meter IC
2
2
A
A
2
2
h (for MUX_DIV = 1)
h (for MUX_DIV = 2)
N
⋅
LSB
ACC
71M6511/71M6511H
⋅
3600
DATA SHEET
⋅
F
S
AUGUST 2007
V2.6