CDB5378 Datasheet, PDF (19/72 Pages) Cirrus Logic – Single-channel Seismic Evaluation System

CDB5378
2.2.4 Delta-Sigma Test DAC
The CS5373A ∆Σ DAC creates differential analog signals for system tests. Multiple test modes are avail-
able and their use is described in the CS5373A data sheet.
Analog Signals
OUT
BUF
CAP
VREF
Description
Precision differential analog output
Buffered differential analog output
Capacitor connection for internal anti-alias filter
Voltage reference analog inputs
Digital Signals
TDATA
MCLK
MSYNC
MODE[0..2]
ATT[0..2]
Description
Delta-sigma test data input
Clock input
Synchronization input
Test mode selection
Attenuation range selection
2.2.4.1 Precision Output - DAC_OUT
The CS5373A test DAC has a precision output (DAC_OUT) that is routed to the input selection jumper.
This output is sensitive to loading, and on CDB5378 should only be jumpered into the INB input which
does not have passive RC filter components installed. The input impedance of the CS3301/02 amplifiers
are high enough that the DAC precision output can be connected to the INB input directly.
2.2.4.2 Buffered Output - DAC_BUF
The CS5373A test DAC has a buffered output (DAC_BUF) that is also routed to the input selection jump-
er. This output is less sensitive to loading than the precision output, and can be jumpered into either the
INA or INB input without affecting performance. The buffered output can also drive a sensor attached to
the input screw terminals, provided the sensor meets the impedance requirements specified in the
CS5373A data sheet.
DS639DB3
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