CS3302A-ISZ Cirrus Logic Inc, CS3302A-ISZ Datasheet - Page 11

• Manufacturer Part Number: CS3302A-ISZ
• Description: Hydrophone Instrumentation Amp
• Manufacturer: Cirrus Logic Inc

Specifications of CS3302A-ISZ

• Amplifier Type: Programmable Gain
• Number Of Circuits: 2
• Output Type: Differential
• Current - Input Bias: 1pA
• Voltage - Input Offset: 250µV
• Current - Supply: 5mA
• Current - Output / Channel: 25mA
• Voltage - Supply, Single/dual (±): ±2.45V ~ 2.55V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 598-1778 - EVALUATION BOARD FOR CS5376
• -3db Bandwidth: -
• Slew Rate: -
• Gain Bandwidth Product: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

DS765PP1
requires two series resistors and a differential capaci-
tor to create the modulator anti-alias RC filter.
2.1.3
Analog signals into and out of the CS3302A are
differential, consisting of two halves with equal but
opposite magnitude varying about a common mode
voltage.
A full scale 5 V
-0.15 V common mode can have:
For the reverse case:
The total swing for SIG+ relative to SIG- is
(+2.5 V) - (-2.5 V) = 5 V
can be done for SIG- relative to SIG+. Note that a
5 V
common mode voltage never exceeds 1.1 V and
never drops below -1.4 V on either half of the sig-
nal.
Differential
SIG+ = -0.15 V + 1.25 V = 1.1 V
SIG- = -0.15 V - 1.25 V = -1.4 V
SIG+ is +2.5 V relative to SIG-
SIG+ = -0.15 V - 1.25 V = -1.4 V
SIG- = -0.15 V + 1.25 V = 1.1 V
SIG+ is -2.5 V relative to SIG-
pp
Sensor
differential signal centered on a -0.15 V
Differential Signals
pp
differential signal centered on a
M
U
X
pp
. A similar calculation
AMP
CS3301A
CS3302A
Figure 4. System Architecture
CS5373A
DS765PP1
CS3302A
Modulator
DAC
Test
∆Σ
By definition, differential voltages are to be mea-
sured with respect to the opposite half, not relative
to ground. A multimeter differentially measuring
between SIG+ and SIG- in the above example
would properly read 1.767 V
2.1.4
The GUARD pin outputs the common mode volt-
age of the currently selected analog signal input. It
can be used to drive the cable shield between a
high-impedance sensor and the amplifier inputs.
Driving the cable shield with the analog signal
common mode voltage minimizes leakage and im-
proves signal integrity from high-impedance sen-
sors.
The GUARD output is defined as the midpoint
voltage between the + and - halves of the currently
selected differential input signal, and will vary as
the signal common mode varies. The GUARD out-
put will not drive a significant load, it only pro-
vides a shielding voltage.
2.2
2.2.1
The CS3302A supports gain ranges of x1, x2, x4,
x8, x16, x32, and x64. They are selected using the
GAIN0, GAIN1, and GAIN2 pins as shown in
Table 1 on page
Digital Signals
Guard Output
Gain Selection
CS5378
Digital Filter
8.
rms
, or 5 V
Configuration
µController
Telemetry
EEPROM
System
CS3302A
or
pp
.
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