DEM-ADS1216 Datasheet, PDF (4/9 Pages) Texas Instruments – EVALUATION FIXTURE

Unipolar/Bipolar
The results of the unipolar/bipolar selection are shown in
Table II.
ANALOG INPUT
DIGITAL OUTPUT
Bipolar
+FSR
Zero
-FSR
0x7FFFFF
0x000000
0x800000
Unipolar
+FSR
Zero
-FSR
0xFFFFFF
0x000000
0x000000
TABLE II. Unipolar/Bipolar Selection Results.
Settling Mode
Three Sinc filters can be selected. When the input changes,
the fast settling filter settles in one data output interval, Sinc²
settles in two periods, and Sinc³ takes three periods to fully
settle. However, the Sinc³ filter has the highest resolution.
The desired filter can be selected. Auto mode selects the fast
settling filter when the input changes, then it changes to the
Sinc² filter for the second period, and on the third data out
period it will use the output of the Sinc³ filter. This gives fast
settling when the input channel changes, but the same high-
resolution results after the necessary number of conversion
periods.
OK
Selecting OK will save the selected setup.
SELECT INPUT CHANNELS
Figure 5 gives a graphical method to select the multiplexer
channel. This also shows the full flexibility of the ADS1216
multiplexer, which allows any input to be selected as the
positive or negative input for a measurement. The mouse
selects which switch to close. Additionally, the internal
diode can be connected, which turns on the burn out current
sources. By measuring the voltage on the diode, a tempera-
ture measurement can be made. IDAC1 can also drive this
sensing diode.
Calibrate Internal Temp Sensor
The Calibrate Temp button opens the Internal Temp Sensor
Calibration window for calibration of the internal tempera-
ture diode. This allows you to force the temperature readout
to match the temperature you enter. This is not intented to
give a high-accuracy temperature readout, but will give a
reading that is reasonable for a single diode voltage mea-
surement.
FIGURE 6. Temperature Calibration.
SET IDAC_S/PGA/V_REF
The screen shown in Figure 7 provides the means to observe
the interaction of the IDAC settings, R_EXT and V_REF. Addi-
tionally, the PGA can be set from this screen.
FIGURE 7. PGA Settings.
FIGURE 5. Input Multiplexer.
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DEM-ADS1216
SBAU038