71M6541D Datasheet, PDF (13/166 Pages) Maxim Integrated Products – 0.1% Accuracy Over 2000:1 Current Range Energy Meter ICs

71M6541D/F/G and 71M6542F/G Data Sheet
Figure 3 shows the 71M6541D/F/G multiplexer interface with one local and one remote resistive shunt
sensor. As seen in Figure 3, when a remote isolated shunt sensor is connected via the 71M6x01, the
samples associated with this current channel are not routed to the multiplexer, and are instead
transferred digitally to the 71M6541D/F/G via the digital isolation interface and are directly stored in CE
RAM.
See Figure 6 for the multiplexer timing sequence corresponding to Figure 3. See Figure 36 for the meter
configurations corresponding to Figure 3.
ILINE
IAP
Local
Shunt
IAN
VADC10 (VA)
MUX
VREF
VREF
VADC
∆Σ ADC
CONVERTER
VREF
FIR
22
IN*
Remote
Shunt
INP
SP
71M6x01
SN
INN
IBP
Digital
Isolation
IBN
Interface
* IN = Optional Neutral Current
CE RAM
22
71M6541D/F
11/5/2010
Figure 3. 71M6541D/F/G AFE Block Diagram with 71M6x01
Figure 4 shows the 71M6542F/G AFE with locally connected sensors. The analog input signals (IAP-IAN,
VA, IBP-IBN and VB) are multiplexed to the ADC input and sampled by the ADC. The ADC output is
decimated by the FIR filter and stored in CE RAM where it can be accessed and processed by the CE.
See Figure 7 for the multiplexer timing sequence corresponding to Figure 4. See Figure 37 for the meter
configuration corresponding to Figure 4.
IA
IA
IAP
CT
or
Local
Shunt
IAN
VADC10 (VA)
MUX
VREF
VREF
VADC
∆Σ ADC
CONVERTER
VREF
FIR
22
CE RAM
VADC9 (VB)
IB
IBP
CT
IBN
71M6542F
11/5/2010
Figure 4. 71M6542F/G AFE Block Diagram (Local Sensors)