CDB5376 Cirrus Logic Inc, CDB5376 Datasheet - Page 19

• Manufacturer Part Number: CDB5376
• Description: EVALUATION BOARD FOR CS5376
• Manufacturer: Cirrus Logic Inc

Specifications of CDB5376

• Main Purpose: Seismic Evaluation System
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: CS3301A, CS3302A, CS4373A, CS5372A, CS5376A
• Primary Attributes: Quad Digital Filter
• Secondary Attributes: Graphical User Interface, SPI™ & USB Interfaces
• Processor To Be Evaluated: CS330x, CS4373A, CS537x
• Interface Type: USB
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant
• Other names: 598-1778

5. OPERATIONAL MODES
The CS4373A has six operational modes and
two sleep modes selected by the MODE2,
MODE1, and MODE0 pins.
5.1 Sleep Modes
Sleep modes (MODE 0, 7) save power during
normal acquisition by turning off the AC and
DC test circuitry after system self-tests are
complete. In sleep mode the OUT and BUF
analog outputs are high impedance.
5.2 AC Test Modes
AC test modes use the digital test bit stream
(TBS) input from the CS5376A digital filter to
construct analog AC waveforms. The digital bit
stream input to the TDATA pin encodes the
analog waveform as over-sampled one bit ∆Σ
data, which is then converted into precision
differential or common mode analog AC sig-
nals by the CS4373A.
5.2.1
The first three AC test modes (MODE 1, 2, 3)
create precision differential analog signals for
THD and impulse testing of the measurement
channel. In mode 1, both sets of differential an-
alog outputs (OUT and BUF) are enabled. In
mode 2 only the OUT analog output is en-
abled, and BUF is high impedance. In mode 3
DS699F2
Selection MODE[2:0]
0
1
2
3
4
5
6
7
AC Differential
Table 2. Operational Modes
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
Sleep mode.
AC OUT and BUF outputs.
AC OUT only, BUF high-z.
AC BUF only, OUT high-z.
DC common mode output.
DC differential output.
AC common mode output.
Sleep mode.
Mode Description
only the BUF analog output is enabled, and
OUT is high impedance.
Differential AC signals out of the CS4373A
consist of two halves with equal but opposite
magnitude, varying about a common mode
voltage. A full-scale 5 V
nal centered on a -0.15 V common mode volt-
age will have:
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-
CS4373A
CS4373A
CS4373A
MODE 2
MODE 3
MODE 1
Figure 8. AC Differential Modes
OUT+
OUT+
BUF+
OUT+
BUF+
OUT-
BUF+
OUT-
OUT-
BUF-
BUF-
BUF-
PP
differential AC sig-
CS4373A
Impedance
Impedance
Differential
Differential
Differential
Differential
Maximum
Maximum
Maximum
Maximum
5 Vpp
5 Vpp
5 Vpp
5 Vpp
High
High
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