AD760 View Datasheet(PDF) - Analog Devices
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AD760 Datasheet PDF : 13 Pages
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CALIBRATED LINEARITY PERFORMANCE
The cumulative probability plots for the AD760 INL and DNL
shown in Figures 3 and 4 represent the maximum absolute-
value (peak) linearity error for each part. Roughly 100 parts
from each of 3 wafer lots were used.
The calibrated DNL and INL performance for the sample
populations shown also represent the expected performance for
a single part calibrated often. There is essentially no difference
between the expected performance of many parts calibrated
once and one part calibrated often. The AD760 calibrated per-
formance is guaranteed at any temperature within the operating
temperature range. The peak nonlinearity for the sample popu-
lations shown are also representative of the expected maximum
linearity errors of a single part recalibrated at temperature.
100
40
80
30
60
20
40
10
20
0
0
0
0.125
0.25
0.375
0.5
0.625
0.75
16-BIT LSB
Figure 3. AD760 Peak INL
50
100
40
80
30
60
20
40
10
20
0
0
0
0.125
0.25
0.375
0.5
16-BIT LSB
Figure 4. AD760 Peak DNL
ANALOG CIRCUIT CONNECTIONS
Internal scaling resistors provided in the AD760 may be con-
nected to produce a unipolar output range of 0 V to +10 V or a
bipolar output range of –10 V to +10 V. Gain and offset drift
are minimized in the AD760 because of the thermal tracking of
the scaling resistors with other device components.
AD760
UNIPOLAR CONFIGURATION
The configuration shown in Figure 5a will provide a unipolar
0 V to +10 V output range. In this mode a 50 resistor is tied
between REF OUT (Pin 26) and REF IN (Pin 25). It is pos-
sible to use the AD760 without any external components by
tying Pin 26 directly to Pin 25. Eliminating this resistor will
increase the gain error by 0.50% of FSR.
AD760
9.95kΩ
+10V REF
10kΩ
10kΩ
MAIN DAC
REFIN
25
50Ω
REFOUT
26
SPAN/BIP OFF
24
23 VOUT
Figure 5a. 0 V to +10 V Unipolar Voltage Output
If it is desired to adjust the gain error to zero, this can be ac-
complished using the circuit shown in Figure 5b. The adjust-
ment procedure is as follows:
STEP 1 . . . OFFSET ADJUST
Initiate calibration sequence. CALOK (Pin 1) must remain high
throughout Gain Adjust.
STEP 2 . . . GAIN ADJUST
Turn all bits ON and adjust gain trimmer, R1, until the output
is 9.999847 volts. (Full scale is adjusted to 1 LSB less than the
nominal full scale of 10.000000 volts.)
AD760
REFI N
25
R1
100Ω
9.95kΩ
+10V REF
10kΩ
10kΩ
MAIN DAC
REFOUT
26
SPAN/BIP OFF
24
23 VOUT
Figure 5b. 0 V to +10 V Unipolar Voltage Output with
Gain Adjust
BIPOLAR CONFIGURATION
The circuit shown in Figure 6a will provide a bipolar output
voltage from –10.000000 V to +9.999694 V with positive full
scale occurring with all bits ON. As in the unipolar mode, resis-
tor R1 may be eliminated altogether to provide AD760 bipolar
operation without any external components. Eliminating this
resistor will increase the gain error by 0.50% of FSR in the
bipolar mode.
REV. B
–7–
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