DG406/407
Vishay Siliconix
APPLICATIONS HINTS
The block diagram shown in Figure 6 illustrates a typical data
acquisition front end suitable for low-level analog signals.
Differential multiplexing of small signals is preferred since
this method helps to reject any common mode noise. This is
especially important when the sensors are located at a
distance and it may eliminate the need for individual
amplifiers. A low r
DS(on)
, low leakage multiplexer like the
DG407 helps to reduce measurement errors. The low power
dissipation of the DG407 minimizes on-chip thermal
gradients which can cause errors due to temperature
mismatch along the parasitic thermocouple paths. Please
refer to Application Note AN203 for additional information.
To
Sensor 1
Analog
Multiplexer
Inst
Amp
S/H
12-Bit
A/D
Converter
To
Sensor 8
DG407
Controller
Figure 6. Measuring low-level analog signals is more accurate when using a differential multiplexing technique.
Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon Tech-
nology and Package Reliability represent a composite of all qualified locations. For related documents such as package/tape drawings, part marking, and reliability
data, see
http://www.vishay.com/ppg?70061.
Document Number: 70061
S-71009–Rev. I, 14-May-07
www.vishay.com
11
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