SPT5216 Ver la hoja de datos (PDF) - Signal Processing Technologies
Número de pieza
componentes Descripción
Fabricante
SPT5216 Datasheet PDF : 10 Pages
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Figure 6 - Typical SPT5216 Application Circuit
Optional Gain Trim Network
R2
10 kΩ
+
15 µF
0.01 µF
330 kΩ
REF
OUT
GAIN REF
ADJ
IN
DAC
RTN 1
DAC
RTN
Sense
BPO
2 kΩ
SPT5216
R-2R Ladder Network
Bandgap
VRef
Gain gm
Adj
Switch
Bias
Network
DAC
RTN 2
1 kΩ
1 kΩ
DAC OUT
+
OP AMP
-
5 V FSR
10 V FSR
VOUT
Range
Selection
VOUT
VEE VEE AGND VCC
.01 µF
+
15 µF
.01 µF
+
15 µF
DGND
.01 µF
+
15 µF
VDD D15
(MSB)
D14
Data Input
D0
(LSB)
VEE AGND
VCC
DGND
VDD
Bipolar
Offset
Connection
470 kΩ
+15 V
10 kΩ
0.1 µF
10 kΩ
R1
10 kΩ
0.1 µF
-15 V
Optional Offset Trim Network
OFFSET AND GAIN CALIBRATION PROCEDURE
This calibration procedure is only applied to the I-to-V appli-
cations as shown in figure 6.
The calibration consists of adjusting the VOUT most negative
voltage to its ideal value for the offset adjustment and
adjusting the most positive VOUT to its ideal value for gain
adjustment. The offset and gain errors listed in the specifica-
tions for both unipolar and bipolar operation may be adjusted
to zero using R1 and R2 (see figure 6) respectively. All
components in the optional offset trim network and optional
gain trim network shown in figure 6 should have a low
temperature coefficient. The potentiometers (R1 and R2)
should be multi-turn components to ensure minute
adjustability.
If the adjustment is not needed, remove the optional offset
trim network from the circuit.
Unipolar
The first step is offset adjustment. Set the input code to 1111
1111 1111 1111 and adjust R1 until VOUT reads zero volts for
either 5 V FSR operation or 10 V FSR operation.
Next is the gain adjustment. Set the input code to 0000 0000
0000 0000 and adjust R2 until VOUT reads +4.999924 volts
for 5 V FSR operation or +9.999846 volts for 10 V FSR
operation.
Bipolar
For the Bipolar mode of operation, start the calibration by
adjusting the offset. Set the input code to 1111 1111 1111
1111 and adjust R1 until VOUT reads -2.50000 volts for 5 V
FSR or -5.00000 volts for 10 V FSR operation. The gain error
calibration is done by setting the input code to 0000 0000
0000 0000 and adjusting R2 until VOUT reads +2.499924 V
for 5 V FSR operation or +4.999848 volts for 10 V FSR
operation.
SPT
7
SPT5216
3/4/97
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