PDF, 333 Kb, Idioma: en, Revisión: D, Archivo subido: oct 9, 2017, Páginas: 29
CMOS, Low Power 24-Bit Sigma-Delta, Signal Conditioning ADC with Matched RTD Current Sources
Extracto del documento
LC2MOS
Loop-Powered Signal Conditioning ADC
AD7713 APPLICATIONS
Loop Powered (Smart) Transmitters
RTD Transducers
Process Control
Portable Industrial Instruments GENERAL DESCRIPTION The AD7713 is a complete analog front end for low frequency
measurement applications. The device accepts low level signals
directly from a transducer or high level signals (4 ⫻ VREF) and
outputs a serial digital word. It employs ⌺-⌬ conversion
technique to realize up to 24 bits of no missing codes
performance. The input 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 register, allowing adjustment of the filter cutoff
and settling time.
The part features two differential analog inputs and one singleended high level analog input as well as a differential reference
input. It can be operated from a single supply (AVDD and DVDD
at 5 V). The part provides two current sources that can be used
to provide excitation in 3-wire and 4-wire RTD configurations.
The AD7713 thus performs all signal conditioning and conversion for a single-, dual-or three-channel system.
The AD7713 is ideal for use in smart, microcontroller-based
systems. Gain settings, signal polarity, and RTD current control …