CRD-5378 Cirrus Logic Inc, CRD-5378 Datasheet - Page 16

• 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
The CS3301A/02A amplifiers act as a low-noise gain stage for internal or external differential analog sig-
nals.
2.2.2.1
By default, CRD5378 uses the CS3302A hydrophone amplifier. The CS3302A amplifier is a very high in-
put impedance device and achieves a 1/f noise performance typically buried below the low-frequency
ocean noise. To minimize leakage from high impedance sensors connected to the CS3302A amplifier, pin
13 produces a GUARD signal output to actively drive a sensor cable shield with the common mode volt-
age of the sensor signal.
Comparing the CS3301A and CS3302A amplifiers, the functionality of pin 13 (MCLK input vs. GUARD
output) is the only external difference. The CS3301A amplifier is chopper-stabilized requiring a clock
source on input pin 13. In order to run the chopper circuitry synchronous to the modulator analog sampling
clock, the CS3301A amplifier pin 13 connects to the CS5378 digital filter (MCLK).
CRD5378 can be converted to use either the CS3301A and CS3302A amplifiers by installing the amplifier
device and populating R8, R9, and R10 with 0 Ω resistors accordingly.
Replacement amplifiers can be requested as samples from the local Cirrus Logic sales representative.
2.2.2.2
The analog outputs of the CS3301A/02A differential amplifiers are split into rough charge and fine charge
signals for input to the CS5373A ∆Σ modulator.
16
Analog Signals
INA
INB
OUTR, OUTF
GUARD
Digital Signals
MUX[0..1]
GAIN[0..2]
PWDN
CLK
Differential Amplifiers
MCLK Input vs. GUARD Output
Rough-Fine Outputs - OUTR, OUTF
Amplifier
Table 7. Amplifier Pin 13 Resistor Settings
Description
Sensor analog input
Test DAC analog input
Analog rough / fine outputs
CS3302A guard output (R10 = 0 Ω, R9 = NO POP)
Description
Input mux selection
Gain range selection
Power down mode enable
CS3301A clock input (R10 = NO POP, R9 = 0 Ω)
U19
CS3301A
R8 + R9
CS3302A
*R10
CRD5378
DS639RD2