
Copyright
Cirrus Logic, Inc. 2006
(All Rights Reserved)
http://www.cirrus.com
CS5373A
Low-power, High-performance
Σ
Modulator and Test DAC
Modulator Features
z
Fourth-order
Σ
Architecture
Clock-jitter-tolerant architecture
Input signal bandwidth: DC to 2 kHz
Max AC amplitude: 5 V
pp
differential
Max DC amplitude: ± 2.5 V
dc
differential
z
High Dynamic Range
127 dB SNR @ 215 Hz BW (2 ms sampling)
124 dB SNR @ 430 Hz BW (1 ms sampling)
z
Low Total Harmonic Distortion
-118 dB THD typical (0.000126%)
-112 dB THD maximum (0.000251%)
z
Low Power Consumption:
25 mW, 10 μW
Test DAC Features
z
Digital
Σ
Input from CS5378 Digital Filter
z
Selectable Differential Analog Outputs
Precision output (OUT±) for electronics tests
Buffered output (BUF±) for sensor tests
z
Multiple AC and DC Operational Modes
Output signal bandwidth: DC to 100 Hz
Max AC amplitude: 5 V
pp
differential
Max DC amplitude: + 2.5 V
dc
differential
z
Selectable Attenuation for CS3301A / CS3302A
1, 1/2, 1/4, 1/8, 1/16, 1/32, 1/64
z
Outstanding Performance
AC (OUT): -116 dB THD typical, -112 dB max
AC (BUF): -108 dB THD typical, -90 dB max
DC absolute accuracy: 0.4% typical, 1% max
z
Low Power Consumption
AC modes / DC modes: 40 mW / 20 mW
Sleep mode / Power down: 1 mW / 10 μW
Common Features
z
Extremely Small Footprint
28-pin SSOP package, 8 mm x 10 mm
z
Bipolar Power Supply Configuration
VA+ = +2.5 V; VA- = -2.5 V; VD = +3.3 V
Description
The CS5373A is a high-performance, fourth-order
Σ
modulator integrated with a
Σ
digital-to-analog convert-
er (DAC). When combined with a CS3301A / CS3302A
differential amplifier and the CS5378 digital filter, a
small, low-power, self-testing, high-accuracy, single-
channel measurement system results.
The modulator has high dynamic range and low total har-
monic distortion with very low power consumption. It
converts differential analog input signals from the
CS3301A / CS3302A amplifier to an oversampled serial
bit stream at 512 kbits per second. This oversampled bit
stream is then decimated by the CS5378 digital filter to a
24-bit output at the selected output word rate.
The test DAC operates in either AC or DC test modes.
AC test modes measure system dynamic performance
through THD and CMRR tests while DC test modes are
for gain calibration and pulse tests. It has two sets of dif-
ferential analog outputs,
OUT
and
BUF
, as dedicated
outputs for testing the electronics channel and for in-
circuit sensor tests. Output attenuation settings are
binary weighted and match the gain settings of the
CS3301A / CS3302A differential amplifiers for full-scale
testing at all gain ranges.
ORDERING INFORMATION
See
page 39
.
24-Bit
Σ
Test DAC
Attenuator
1/1 to 1/64
Clock
Generator
VA+
MODE(0, 1, 2)
ATT(0, 1, 2)
VD
VA-
VREF+
VREF-
GND
MCLK
MSYNC
24-Bit
Σ
Modulator
OUT+
OUT-
BUF+
BUF-
TDATA
CAP+
CAP-
MDATA
MFLAG
INR+
INF+
INF-
INR-
DEC ‘06
DS703F1