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KAD/ADC/129/S2
INFO: CURTISSWRIGHT.COM
EMAIL: [email protected]
KAD/ADC/129/S2
Full-bridge ADC (voltage excitation, programmable analog gain,
sense lines, 25kHz b/w) - 4ch at 100ksps
Key Features
•
Four full or ½-bridge, potentiometer or
differential ended input channels
•
Programmable input range (±10mV to ±10V)
•
High accuracy (0.02% FSR typical for range of
1V and 10V)
•
Programmable voltage excitation with
separate sense lines and balance adjust
•
Short on any channel does not affect others
•
16-bit simultaneous sampling on each channel
Applications
•
Bridge sensors and strain gage measurement
•
Differential voltage measurement
Overview
The KAD/ADC/129/S2 has four channels of signal conditioning and data
acquisition for differential voltages, strain gage or bridge measurements.
In addition to the measurement channel, the KAD/ADC/129/S2 provides
independent bipolar excitation for up to four channels. Each differential
ended signal has a separate programmable amplifier, filter and A/D
converter.
At the heart of the KAD/ADC/129/S2 is a hard-wired state-machine that
over-samples all channels at a rate between 200ksps and 400ksps and
digitally filters any noise above the user-programmable cutoff frequency.
This is achieved using cascaded, half-band, decimate by 2 x 15-tap,
Finite-Impulse-Response (FIR) filters followed by an 8
th
order Butterworth
Infinite-Impulse-Response (IIR) filter with a default cutoff point set at a
quarter of the sampling frequency. All signals are sampled simultaneously.
Thus, when several channels are sampled at different sampling rates, all
channels will be aligned at the start of an acquisition cycle.
The KAD/ADC/129/S2 is intended for use with strain gages, and should
not be used for asymmetric bridge transducers such as accelerometers,
pressure transducers unless sensor re-calibration is carried out on a
channel-by-channel basis. If the sense lines or internal offset adjust
(balance feature) are not required, refer to the KAD/ADC/129/S1.
Figure 1: First of four channels on the KAD/ADC/129/S2
ANALOG(0)
EXC_V(0)+
KAD/ADC/129/S2
ANALOG
DIGITAL
COUNTS
UNITS
+
-
DIGITAL
ANALOG
GAIN [1, 10, 100, 1000]
INST. AMP
AAAF
DIGITAL FILTER
LOOKUP TABLE
34.8K [RADJ ]
VADJ
DIGITAL
ANALOG
VREF
+
-
+
-
+
-
ST
AN
D
AR
D
BU
S
IN
T
ER
F
AC
E
AN
D
L
O
G
IC
51
GND
1
2
5
4
3
6
SENSE(0)+
+
EXC_V(0)-
SENSE(0)-
+
-
-