CS5471
2. GENERAL DESCRIPTION
2.1
Theory of Operation
The CS5471 is designed for single-phase power The CS5471 is designed to operate from a single
meter applications and interfaces to a current trans- +3V supply and provides a 40 mV and 800 mV
formers or shunt to measure current, and a resistive
divider or transformer to measure voltage.
input range for the current channel and 800 mV
range for the voltage channel. These voltages rep-
resent the maximum zero-to-peak voltage levels
that can be presented to the inputs. The CS5471 is
designed to accommodate common mode + signal
levels from VA- to VA+. Figure 2 illustrates the
CS5471 typical inputs and power supply connec-
tions.
The CS5471 combines two ∆Σ modulators and
decimation filters, one channel assigned for current
input that has programmable input gain amplifiers,
and one channel assigned for voltage input.
The CS5471 includes two decimation filters that
output data at a 2000 Hz or 4000 Hz output word
rate (OWR) when the input frequency at XIN =
4.096 MHz.
2.2
Performing Measurements
The converter outputs are transferred in 16-bit
signed (two’s complement) data formats as a per-
The device outputs data on a serial output port.
+3 V
VD+
VA+
REFIN
Optional
External
REFOUT
1.2 V
Reference
+
VIN
+
V
PHASE
-
VIN
IIN+
I
PHASE
NOTE: Current input channel
actually measures voltage.
IIN-
AGND
VA-
DGND
-2 V
Figure 2. Typical Connection Diagram
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