Datasheet

71M6513/71M6513H
3-Phase Energy Meter IC
DATA SHEET
AUGUST 2011
Page: 68 of 104 © 2005-2011 Teridian Semiconductor Corporation
A Maxim Integrated Products Brand
During operation, the MPU is in charge of controlling the multiplexer cycles, for example by inserting an alternate multiplexer
sequence at regular intervals using MUX_ALT. This enables temperature measurement. The polarity of CHOP must be altered
for each sample. It must also alternate for each alternate multiplexer reading.
The MPU must program CHOP_EN alternately between 01 and 10 on every CE_BUSY interrupt except for the first CE_BUSY
after an XFER_BUSY interrupt. Note that when XFER_BUSY occurs, it will always be at the same time as a CE_BUSY
interrupt.
Operating CE codes with environment parameters deviating from the values specified by Teridian will lead to
unpredictable results.
CE Calculations
The CE performs the precision computations necessary to accurately measure power. These computations include offset
cancellation, phase compensation, product smoothing, product summation, frequency detection, VAR calculation, sag
detection, peak detection, and voltage phase measurement. All data computed by the CE is dependent on the selected meter
equation as given by EQU (in I/O RAM). As a function of EQU, the element components V0 through I2 take on different
meanings.
EQU
Watt & VAR Formula
(WSUM/VARSUM)
Element Input Mapping
W0SUM/
VAR0SUM
W1SUM/
VAR1SUM
W2SUM/
VAR2SUM
I0SQ
SUM
I1SQ
SUM
I2SQ
SUM
0
VA IA (1 element, 2W 1φ)
VA*IA - - IA - -
1
VA*(IA-IB)/2
(1 element, 3W 1φ)
VA*(IA-IB)/2 - (IA-IB) IB -
2
VA*IA + VB*IB
(2 element, 3W 3φ Delta)
VA*IA VB*IB - IA IB -
3
VA*(IA-IB)/2 + VC*IC
(2 element, 4W 3φ Delta)
VA*(IA-IB)/2 - VC*IC IA-IB IB IC
4
VA*(IA-IB)/2 + VB*(IC-IB)/2
(2 element, 4W 3φ Wye)
VA*(IA-IB)/2 VB*(IC-IB)/2 - IA-IB IC-IB IC
5
VA*IA + VB*IB + VC*IC
(3 element, 4W 3φ Wye)
VA*IA VB*IB VC*IC IA IB IC
CE RAM Locations
The information given in the following tables apply to CE code Version CE13B09D.