CS3301 Datasheet, PDF (10/16 Pages) Cirrus Logic – Low-noise, Programmable Gain, Differential Amplifier

CS3301
2. GENERAL DESCRIPTION
The CS3301 is a low-noise chopper-stabilized
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 amplifier’s performance makes it ideal for
low-frequency, high dynamic range applications
requiring low distortion and minimal power con-
sumption. It’s optimized for use in acquisition sys-
tems designed around the CS5371/72 single/dual
∆Σ modulators and the CS5376A quad digital fil-
ter. Figure 3 shows the system architecture of a 4-
channel acquisition system using four CS3301, two
CS5372, one CS4373A, and one CS5376A.
2.1 Analog Signals
2.1.1 Analog Inputs
The amplifier analog inputs are designed for differ-
ential sensors. Input multiplexing simplifies sys-
tem connections by providing separate inputs for a
sensor and test DAC (INA, INB) as well as an in-
ternal termination for noise tests. The MUX0,
MUX1 digital pins determine which multiplexed
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 CS5371/72 inputs. Each output also includes
a series resistor, requiring only two differential ca-
pacitors to create the CS5371/72 input anti-alias
filter.
Geophone
or
Hydrophone
Sensor
Geophone
or
Hydrophone
Sensor
Geophone
or
Hydrophone
Sensor
Geophone
or
Hydrophone
Sensor
CS3301
M
CS3302
U
AMP
X
CS5371
CS5372
∆Σ
Modulator
CS3301
M
CS3302
U
AMP
X
CS3301
M
CS3302
U
AMP
X
CS5371
CS5372
∆Σ
CS3301
Modulator
M
CS3302
U
AMP
X
Switch
SMwUitcXh
MUX
CS5376A
Digital Filter
CS4373A
Test
DAC
System Telemetry
µController
or
Configuration
EEPROM
Communication
Interface
Figure 3. Multi-Channel System Architecture
10
DS595F2