CS3302A Datasheet, PDF (10/16 Pages) Cirrus Logic – High-Z, Programmable Gain, Differential Amplifier

CS3302A
DS765PP1
CS3302A
2. GENERAL DESCRIPTION
The CS3302A is a high-impedance, low-noise
CMOS differential input, differential output ampli-
fier for precision analog signals between DC and
2 kHz. It has multiplexed inputs, rough/fine charge
outputs, and programmable gains of x1, x2, x4, x8,
x16, x32, and x64.
The performance of this amplifier makes it ideal
for low-frequency, high-dynamic-range applica-
tions requiring low distortion and minimal power
consumption. It is optimized for use in acquisition
systems designed around the CS5371A/72A sin-
gle/dual ∆Σ modulators and the CS5376A quad
digital filter or the CS5373A ∆Σ modulator and
CS5378 digital filter. Figure 3 shows the system-
level architecture of a 4-channel acquisition system
using four CS3302A, two CS5372A, one
CS4373A, and one CS5376A. Figure 4 shows the
system architecture of a single channel acquisition
system using a CS3302A, CS5373A, and CS5378.
2.1 Analog Signals
2.1.1 Analog Inputs
The amplifier analog inputs are designed for high-
impedance differential sensors. Input multiplexing
simplifies system connections by providing sepa-
rate inputs for a sensor and test DAC (INA, INB) as
well as an internal termination for noise tests. The
MUX0, MUX1 digital pins determine which multi-
plexed input is connected to the amplifier.
2.1.2 Analog Outputs
The amplifier analog outputs are separated into rough
charge / fine charge signals to easily connect to the
CS5371A/72A/73A inputs. Each differential output
Geophone
or
Hydrophone
Sensor
Geophone
or
Hydrophone
Sensor
Geophone
or
Hydrophone
Sensor
Geophone
or
Hydrophone
Sensor
10
CS3301A
CS3302A
M
U
AMP
X
CS5371A
CS5372A
∆Σ
CS3301A
Modulator
CS3302A
M
U
AMP
X
CS3301A
CS3302A
M
U
AMP
CS5371A
X
CS5372A
∆Σ
CS3301A
Modulator
CS3302A
M
U
AMP
X
Switch
SMwUitXch
MUX
CS5376A
Digital Filter
CS4373A
Test
DAC
Figure 3. System Architecture
System Telemetry
µController
or
Configuration
EEPROM
Communication
Interface
DS765PP1