71M6515H-IGT/F Maxim Integrated Products, 71M6515H-IGT/F Datasheet - Page 46

• Manufacturer Part Number: 71M6515H-IGT/F
• Description: IC ENERGY METER AFE 3PH 64-LQFP
• Manufacturer: Maxim Integrated Products

Specifications of 71M6515H-IGT/F

• Mounting Style: SMD/SMT
• Package / Case: LQFP-64
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

WH_A (0x00), WH_B (0x01), WH_C (0x02)
FREQ_DELTA_T (0x11)
MAIN_EDGE_CNT (0x35)
Registers Controlling Alarms and Thresholds
CREEP_THRSLD (0x1D)
SAG (0x2E)
Page: 46 of 60
If higher precision is required, the host must calculate the RMS voltages from the values in the VASQSUM, VBSQSUM, and
VCSQSUM registers.
These registers hold the real energy collected during the previous accumulation interval. The magnitude of the values is
determined by:
This register holds frequency and temperature information in two bytes each.
Bits 31-16: These bits (FREQUENCY) represent the frequency of the input signal selected with the F_SELECT bit of the
CONFIG register. One LSB is equivalent to 0.1Hz.
This register holds the number of zero crossings of the input phase selected by the F_SELECT bits in the CONFIG register
detected in the previous accumulation interval. The value in MAIN_EDGE_CNT can be used by the host to correct its own
RTC or to synchronize events to the line voltage.
The four bytes written to this register determine the creep threshold. Setting a creep threshold helps suppressing I2H, Wh
and VARh readings when the values of WSUM and VARSUM are determined to be below the creep threshold.
This register holds the voltage and timing threshold for sag detection.
Bits 15-0: These bits (SAG_CNT) hold the sag count. A sag condition must persist for at least SAG_CNT samples before a
sag alarm is generated. The allowed range is 1 to (2
SAG_CNT is:
LSB
=
T = SAG_CNT*397µs
. 9
A Maxim Integrated Products Brand
4045
The rounded down value of 8520 is written to the CREEP_THRSLD register.
By multiplying with 3,600, we get 100Wh/h, which means the applied power is 100W.
Example: The register WH_A reads the value 236,675 for one accumulation interval of one second. Assuming
600V for VMAX, 208A for IMAX, and unity gain, we determine the real energy to be:
E = 236,675*600*208*9.4045*10
of 8. The numerical value for the CREEP_THRSLD register is to be determined.
Example: The creep threshold of a meter operating with an accumulation interval of 1000ms is to be configured
to be 15mA at 240V. The meter is using a VMAX of 600V, an IMAX of 208A, and is not using the additional gain
With 15mA, the power per phase will be 3.6W, or 0.001Wh per second. With the LSB of WSUM readings given
as 9.4045*10
Example: The register VRMS_B reads the value 425,778,000. Assuming VMAX to be 600V, and using the
formula above, we determine the RMS voltage of phase B to:
V
RMS
⋅
10
n = 0.001Wh / (9.4045*10
−
=
13
425778000
VMAX
-13
In
*VMAX*IMAX [Wh], we determine the value to:
_
IMAX
8
⋅
. 6
8781
Wh
© 2005−2011 Teridian Semiconductor Corporation
⋅
60
10
−
-13
9
600
-13
*VMAX*IMAX /In_8 Wh) = 8520.2
Wh = 0.0277781Wh.
=
226
.
85
V
15
-1), and the default is 80 (31.7ms). The time period defined by
Energy Meter IC
DATA SHEET
71M6515H
JULY 2011
1.6