Datasheet

71M6515H
Energy Meter IC
DATA SHEET
JULY 2011
Page: 38 of 60 © 2005−2011 Teridian Semiconductor Corporation 1.6
A Maxim Integrated Products Brand
Bits 13-8: These six bits (SUM_CYCLES) define the length of the accumulation interval τ per the formula:
6.2520
42_ ⋅
=
CYCLESSUM
τ
Allowed values are 24 (400ms) through 60 (1000ms), unless the post-processor is disabled. Bit 8 is the LSB.
It is important to note that the length of the accumulation interval, as determined by SUM_CYCLES, is not an exact multiple
of 1000ms. For example, if SUM_CYCLES = 60, the resulting accumulation interval is:
ms
Hz
Hz
75.999
62.2520
2520
13
32768
4260
==
⋅
=
τ
This means that accurate time measurements should be based on the RTC, not the accumulation interval.
Bit 14: This bit (CKOUT_DISB) disables the CKOUT pin when set. The CKOUT pin can be used for diagnostics. For EMC
compliance and power saving reasons, CKOUT_DISB should always be set.
Bit 15: This bit (ADC_DIS) disables the ADC when set, e.g. to save power. Of course, no metering or measuring can be
performed with the ADC disabled.
Bits 18-16: These three bits (TMUX) select the source for the TMUX diagnostic output pin. For EMC compliance and
power saving reasons, TMUX should be zero (default) if unused.
Bit 18
TMUX2
Bit 17
TMUX1
Bit 16
TMUX0
TMUX
Signal Selected for the TMUX Pin
0
0
0
0
GND
0
0
1
1
MUX_SYNC
0
1
0
2
RTM
0
1
1
3
RTC Output
1
0
0
4
CE_BUSY
1
0
1
5
XFER_BUSY
1
1
0
6
VX_OK (Comparator Output)
1
1
1
7
V3P3/2 =1.5V internal analog voltage