Datasheet

-2.5V
+2.5V
+5V
12
5
6
3 4
R
1
10kW
R
2
10kW
-5V
+5V
OPA735
REF3225
ADS7822
REF3233
V
CC
CS
D
OUT
DCLOCK
V
REF
+In
-In
GND
GND
V
IN
V
S
+
+
5W
1mFto10mF
0.47 Fm
1 Fto10 Fm m
0.1 Fm
Microcontroller
V+
3.3V
2 1
35
6
4
REF3212, REF3220
REF3225, REF3230
REF3233, REF3240
www.ti.com SBVS058C –JUNE 2005– REVISED AUGUST 2011
APPLICATION CIRCUITS
NEGATIVE REFERENCE VOLTAGE
For applications requiring a negative and positive
reference voltage, the REF32xx and OPA735 can be
used to provide a dual-supply reference from a ±5V
supply. Figure 25 shows the REF3225 used to
provide a ±2.5V supply reference voltage. The low
drift performance of the REF32xx complements the
low offset voltage and zero drift of the OPA735 to
provide an accurate solution for split-supply
applications. Care must be taken to match the
temperature coefficients of R
1
and R
2
.
DATA ACQUISITION
Data acquisition systems often require stable voltage
references to maintain accuracy. The REF32xx family
features stability and a wide range of voltages
NOTE:: Bypass capacitor is not shown.
suitable for most microcontrollers and data
converters. Figure 26, Figure 27, and Figure 28 show
Figure 25. REF3225 Combined with OPA735 to
basic data acquisition systems.
Create Positive and Negative Reference Voltages
Figure 26. Basic Data Acquisition System 1
Copyright © 2005–2011, Texas Instruments Incorporated 11