EVAL-AD7795 Datasheet, PDF (1/16 Pages) Analog Devices – Evaluation Board for the AD7795 16-Bit, Low Power Sigma-Delta ADC (6 Channels)

Evaluation Board for the AD7795 16-Bit,
Low Power Sigma-Delta ADC (6 Channels)
EVAL-AD7795
FEATURES
Full-featured evaluation board for the AD7795
Standalone USB interface
Various linking options
PC software for control of AD7795
GENERAL DESCRIPTION
This data sheet describes the evaluation board for the AD7795,
a low power, 16-bit Σ-Δ ADC. The AD7795 is a complete
analog front end for low frequency measurement applications.
It contains six differential inputs and includes a low noise
instrumentation amplifier, an embedded reference, as well as
programmable current sources and a low-side power switch.
The update rate can be varied from 4.17 Hz to 500 Hz. It also
has an on-board clock, eliminating the need for an external
clock. It employs a Σ-Δ conversion technique to realize up to
16 bits of no missing codes performance. The input signal is
applied to an analog modulator. The modulator output is
processed by an on-chip digital filter. The analog input channel
of the AD7795 accepts analog input signals of ±VREF/gain, with
gain equal to 1 to 128. With a gain of 64 and the update rate
programmed to 16.7 Hz, the rms noise is 86 nV. Simultaneous
50 Hz/60 Hz rejection is also available at this data update rate.
Full details on the AD7795 are available in the AD7795 data
sheet, available from Analog Devices, Inc., and should be
consulted in conjunction with this data sheet when using the
evaluation board.
The evaluation board interfaces to the USB port of an IBM-
compatible PC. Software is available with the evaluation board,
which allows the user to communicate easily with the AD7795.
Note that the AD7795 evaluation board software must be installed
before connecting the AD7795 evaluation board to the PC.
Other components on the AD7795 evaluation board include
the ADP3303 high precision, low power, 3.3 V output, voltage
regulator, which is used to power the USB/SPI interface.
FUNCTIONAL BLOCK DIAGRAM
AVDD
TEMPERATURE
SENSOR
VOLTAGE
REGULATOR
ANALOG _AD7795
INPUTS
SPI/USB
INTERFACE
Figure 1.
USB
CONNECTOR
PC AND
LabVIEW™
BASED
SOFTWARE
Rev. 0
Evaluation boards are only intended for device evaluation and not for production purposes.
Evaluation boards are supplied “as is” and without warranties of any kind, express, implied, or
statutory including, but not limited to, any implied warranty of merchantability or fitness for a
particular purpose. No license is granted by implication or otherwise under any patents or other
intellectual property by application or use of evaluation boards. Information furnished by Analog
Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result
from its use. Analog Devices reserves the right to change devices or specifications at any time
without notice. Trademarks and registered trademarks are the property of their respective owners.
Evaluation boards are not authorized to be used in life support devices or systems.
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