ad7710en.pdf

The AD7710 is a complete analog front end for low frequency
measurement applications. The device accepts low level signals
directly from a strain gage or transducer and outputs a serial
digital word. It employs a sigma-delta conversion technique to
realize up to 24 bits of no missing codes performance. The inp
signal is applied to a proprietary programmable gain front end
based around an analog modulator. The modulator output is
processed by an on-chip digital filter. The first notch of this
digital filter can be programmed via the on-chip control registe
allowing adjustment of the filter cutoff and settling time.
The part features two differential analog inputs and a differen-
tial reference input. Normally, one of the channels will be used
as the main channel with the second channel used as an auxil-
iary input to periodically measure a second voltage. It can be
operated from a single supply (by tying the VSS pin to AGND)
provided that the input signals on the analog inputs are more
positive than –30 mV. By taking the VSS pin negative, the part
can convert signals down to –VREF on its inputs. The AD7710
thus performs all signal conditioning and conversion for a singl
or dual channel system.
The AD7710 is ideal for use in smart, microcontroller based
systems. Input channel selection, gain settings and signal polar
ity can be configured in software using the bidirectional serial
port. The AD7710 contains self-calibration, system calibration
and background calibration options and also allows the user to
read and write the on-chip calibration registers.