cs5461 Cirrus Logic, Inc., cs5461 Datasheet - Page 5

• Manufacturer Part Number: cs5461
• Description: Single-phase, Bidirectional Power/energy Ic
• Manufacturer: Cirrus Logic, Inc.

CS5461
1. GENERAL DESCRIPTION
The CS5461 is a CMOS monolithic power measurement device with a real power/energy computation en-
gine. The CS5461 combines two programmable gain amplifiers, two ∆Σ modulators, two high-rate filters,
system calibration, and calculation functions. The device provides instantaneous voltage and current data
samples and calculates average (real) power, V
, I
, and instantaneous power data samples.
RMS
RMS
The CS5461 functionality is optimized for power measurement applications and is optimized to interface
to a shunt or current transformer for current measurement, and to a resistive divider or potential transform-
er for voltage measurement. To accommodate various input voltage levels from a multitude of current sen-
sors, the CS5461’s current channel has a front-end-programmable gain amplifier (PGA), which allows for
two available full-scale differential input signal ranges on the current channel: 100 mV
and 500 mV
,
P-P
P-P
while the voltage channel has a set input range of 500 mV
. With single +5 V (common-mode) supply
P-P
across VA+/VA-, both of the CS5461’s input channels can accommodate (common-mode + signal) levels
between -0.25 V and VA+. This allows for a completely bipolar differential input configuration. The com-
mon-mode voltage level of the differential input signals can be anywhere between the supply voltage levels
on the VA+/VA- pins, as long as enough voltage margin is left over so that the addition of the differential
signals will not cause the total swing to go below -0.25 V or above +5 V.
The CS5461 includes two high-rate digital filters, which decimate the output from the two ∆Σ modulators.
These filters integrate the output of the ∆Σ modulators for both channels to yield instantaneous voltage and
current waveform output data at a (MCLK/K)/1024 output word rate (OWR).
To facilitate communication to a microcontroller, the CS5461 includes a simple three-wire serial interface
which is SPI™ and Microwire™ compatible.
DS546F2
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