OPA333_17 Datasheet, PDF (15/42 Pages) Texas Instruments – 1.8-V, microPower, CMOS Operational Amplifiers, Zero-Drift Series

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8 Application and Implementation
OPA333, OPA2333
SBOS351E – MARCH 2006 – REVISED DECEMBER 2015
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The OPAx333 family is a unity-gain stable, precision operational amplifier with very low offset voltage drift; these
devices are also free from output phase reversal. Applications with noisy or high-impedance power supplies
require decoupling capacitors close to the device power-supply pins. In most cases, 0.1-μF capacitors are
adequate.
8.2 Typical Applications
8.2.1 High-Side Voltage-to-Current (V-I) Converter
The circuit shown in Figure 20 is a high-side voltage-to-current (V-I) converter. It translates in input voltage of 0 V
to 2 V to and output current of 0 mA to 100 mA. Figure 21 shows the measured transfer function for this circuit.
The low offset voltage and offset drift of the OPA333 facilitate excellent dc accuracy for the circuit.
V+
V_IN ⁺
±
V+
+
A1
R_S2
470
VRS2
I_RS2
10 k ^R4
R_S3
4.7
C₇
2200 pF
I_RS3
VRS3
R₅
A2
+
330
Q2
200
Q1
R₃
1000 pF
C₆
10 k _R2
R_S1
2k
VRS1
I_RS1
R_LOAD
VLOAD
I_LOAD
Figure 20. High-Side Voltage-to-Current (V-I) Converter
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Product Folder Links: OPA333 OPA2333
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