CS5464-IS Cirrus Logic Inc, CS5464-IS Datasheet - Page 14

• Manufacturer Part Number: CS5464-IS
• Description: Other Power Management 3-Ch Single Phase Power/Energy IC
• Manufacturer: Cirrus Logic Inc

Specifications of CS5464-IS

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

4. SIGNAL PATH DESCRIPTION
The data flow for voltage and current measurement and
the other calculations are shown in Figures 3, 4, and 5.
The data flow consists of two current paths and two volt-
age paths. Both voltage paths are derived from the
same differential input pins. Each current path has its
own differential input pins.
4.1 Analog-to-Digital Converters
The voltage and temperature channels use second-or-
der delta-sigma modulators and the two current chan-
nels use fourth-order delta-sigma modulators to convert
the analog inputs to single-bit digital data streams. The
converters sample at a rate of DCLK/8. This high sam-
pling provides a wide dynamic range and simplifies an-
ti-alias filter design.
4.2 Decimation Filters
The single-bit modulator output data is widened to
24 bits and down-sampled to DCLK/1024 with low-pass
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Figure 3. Signal Flow for V1, I1, P1, Q1 Measurements
Figure 4. Signal Flow for V2, I2, P2, Q2 Measurements
V1
I1
V2
I2
OFF
OFF
OFF
OFF
decimation filters. These decimation filters are third-or-
der Sinc. Their outputs are passed through third-order
IIR “anti-sinc” filters, used to compensate for the ampli-
tude roll-off of the decimation filters.
4.3 Phase Compensation
Phase compensation changes the phase of current rel-
ative to voltage by changing the sampling time in the
decimation filters. The amount of phase shift is set by
bits PC[7:0] in the Configuration register ( Config ) for
channel 1 and bits PC[7:0] in the Control register ( Ctrl )
for channel 2.
Phase compensation, PC[7:0] is a signed two’s comple-
ment binary value in the range of -1.0 to almost +1.0
output word rate (OWR) samples. For a sample rate of
4000 Hz, the delay range is ±250 µ S, a phase shift of
±4.5° at 50 Hz and ±5.4° at 60 Hz. The step size would
be 0.0352° at 50 Hz and 0.0422° at 60 Hz at this sample
rate.
V1
I1
V2
I2
GAIN
GAIN
GAIN
GAIN
CS5464
DS682F1