Cirrus-logic CDB5374 Manual de usuario descargar pdf (Pagina 18)

CDB5374

18 DS862DB1

2.2.4 Delta-Sigma Test DAC

The CS4373A DAC creates differential analog signals for system tests. Multiple test modes are available

and their use is described in the CS4373A data sheet.

2.2.4.1 Precision Output - DAC_OUT

The CS4373A test DAC has a precision output (DAC_OUT) that is routed to the input selection jumpers

for each channel. This output is sensitive to loading, and on CDB5374 should only be jumper-ed into the

INB inputs which do not have passive RC filter components installed. The input impedance of the INB am-

plifier inputs are high enough that the precision output can be directly connected to the INB inputs of all

channels simultaneously.

2.2.4.2 Buffered Output - DAC_BUF

The CS4373A test DAC has a buffered output (DAC_BUF) that is routed to the input selection jumpers

for each channel. This output is less sensitive to loading than the precision outputs, and can be jumper-

ed into either the INA or INB inputs 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 CS4373A data sheet.

Analog Signals Description

OUT Precision differential analog output

BUF Buffered differential analog output

CAP Capacitor connection for internal anti-alias filter

VREF Voltage reference analog inputs

Digital Signals Description

TDATA Delta-sigma test data input

MCLK Clock input

SYNC Synchronization input

MODE[0..2] Test mode selection

ATT[0..2] Attenuation range selection

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Cirrus-logic CDB5374 Manual de usuario Pagina 18