True 24-bit ADC eliminates the need for autoranging
The new PS2400 analogue-to-digital
converter (ADC) board from
Earth Data Ltd, part of
the Southampton-based Kenda Group,
provides three independent channels of 24-bit conversion and
offers true 24-bit dynamic range. It can resolve signals from
1µV to ±8V in its normal gain mode or 50nV to
±400mV in its high
gain mode.
The wide dynamic range enables the ADC to monitor both small
and
large signals without the attendant range errors and the loss
of
resolution at high signal levels associated with autoranging
converters.
Offering programmable sample rates from 25 to 1000Hz, the
ADC
achieves a signal-to-noise ratio of better than 140dB up to
100Hz and 130dB at 1000Hz.
The PS2400 employs a 7th
order Delta Sigma architecture
resulting from a 5-year development programme aimed at
overcoming the compromises found in standard chipsets used
by
other manufacturers.
Featuring auto calibration of zero offset and gain, the ADC
also
includes temperature compensation to maintain an offset voltage
drift of only 0.2µV/ºC over the full operating
temperature range
of -40º to +60ºC.
The ADC is equipped with an RS232 port for control of the
unit
and retrieval of data. In addition, it can be operated with
a
GPS receiver which maintains timing accuracy and identifies,
within the transmitted RS232 data, the UTC time and the unit's
global position.
Using multilayer PCB and surface-mount technologies, the PS2400
can be supplied as a Eurocard or fully packaged in a waterproof
housing. It is primarily aimed at data-acquisition systems
used
in seismic, oil-exploration, hydrographic survey, engineering,
mining and automotive applications.
- ends -
15th October 1997 Ref. KE116/2
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