CRD-5378 Cirrus Logic Inc, CRD-5378 Datasheet - Page 19

• Manufacturer Part Number: CRD-5378
• Description: Audio Modules & Development Tools Ref Bd LP Sngl-Ch Decimation Filter
• Manufacturer: Cirrus Logic Inc

Specifications of CRD-5378

• Description/function: Audio D/A
• Operating Supply Voltage: 3.3 V
• Product: Audio Modules
• Supply Current: 100 mA
• For Use With/related Products: CS3302A, CS5373A, CS5378
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2.2.5.1
The voltage reference output is provided to the CS5373A ∆Σ modulator and test DAC through a low-pass
RC filter. By filtering the voltage reference to the device, high-frequency noise is eliminated and any sig-
nal-dependent sampling of VREF is isolated. The voltage reference signal is routed as a separate differ-
ential pair from the large RC filter capacitor to control the sensitive VREF source-return currents and keep
them out of the ground plane. In addition to the RC filter function, the 68 uF filter capacitor provides a large
charge-well to help settle voltage reference sampling transients.
2.3
2.3.1
The CS5378 digital filter performs filtering and decimation of the ∆Σ bit stream from the CS5373A modu-
lator. It also creates a ∆Σ bit stream output to create analog test signals in the CS5373A test DAC.
The CS5378 requires several control signal inputs from the external system.
Configuration and data collection are through the SPI port.
Modulator ∆Σ data is input through the modulator interface, and test DAC ∆Σ data is generated by the test
bit stream generator.
DS639RD2
Digital Hardware
Control Signals
RESETz
BOOT
TIMEB
CLK
SYNC
SPI1 Signals
DRDYz
SCK
MISO
MOSI
SS: EECSz
Modulator Signals
MCLK
MSYNC
MDATA
MFLAG
TBSDATA
Digital Filter
VREF_MOD
Description
Data ready output, active low
Serial clock
Master in / slave out serial data
Master out /slave in serial data
Serial chip select, active low
Description
Modulator clock output
Modulator synchronization output
Modulator delta-sigma data input
Modulator over-range flag input
Test DAC delta-sigma data output
Description
Reset input, active low
Microcontroller / EEPROM boot mode select
Time Break input, rising edge triggered
Master clock input, 32.768 MHz
Master synchronization input, rising edge triggered
CRD5378
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