CRD-5378 Cirrus Logic Inc, CRD-5378 Datasheet - Page 13

• 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
2.2.1
2.2.1.1
External signals into CRD5378 are from two major classes of sensors, moving coil geophones and piezo-
electric hydrophones. Geophones are low-impedance sensors optimized to measure vibrations in land
applications. Hydrophones are high-impedance sensors optimized to measure pressure in marine appli-
cations. Other sensors for earthquake monitoring and military applications are considered as geophones
for this data sheet.
External signals connect to CRD5378 through a 3-pin header on the left side of the PCB. This header
makes a connection to the differential INA amplifier inputs and to either a GND or GUARD signal for con-
nection to the sensor cable shields, if present.
2.2.1.2
The CS3302A hydrophone amplifier provides a GUARD signal output on pin 13 designed to actively drive
the cable shield of a high impedance sensor with the common mode voltage of the sensor differential sig-
nal. This GUARD output on the cable shield minimizes leakage by minimizing the voltage differential be-
tween the sensor signal and the cable shield. The CS3301A geophone amplifier does not have a GUARD
output. Instead, the CS3301A amplifier expects an MCLK clock input to pin 13, which is needed for its
chopper stabilization circuitry. When using a CS3301A amplifier, a cable shield termination to GND is pro-
vided for the sensor connection.
By default, CRD5378 uses the CS3302A amplifier. Therefore, the GUARD signal is connected to pin 3 of
the input signal header, J4.
To configure CRD5378 with the CS3301A geophone amplifier, simply make the following three changes:
2.2.1.3
The CS5373A test DAC has two high performance differential test outputs, a precision output (DAC_OUT)
and a buffered output (DAC_BUF). The DAC_OUT signal is wired directly to the INB inputs of the
CS3302A amplifier for testing the performance of the electronics channel. The DAC_BUF signal is wired
to the INA inputs of the amplifier and is used to test the performance of the measurement channel with a
sensor attached.
DS639RD2
1) De-solder the 0 Ω resistor at R10 to remove the GUARD signal from pin 3 of J4.
2) Populate R8 with a 0 Ω resistor to provide a cable shield termination to GND.
3) Populate R9 with a 0 Ω resistor so that the CS3301A amplifier can receive its required master clock
(MCLK) from the CS5378 digital filter.
Analog Hardware
Analog Inputs
External Inputs - INA
GUARD Output, GND Connection
Internal Inputs - DAC_OUT, DAC_BUF
Table 6. Pin Header Input Connections
Signal Input
CH1 INA
Pin Header
J4
CRD5378
13