OPA191_017 Datasheet, PDF (31/51 Pages) Texas Instruments – 36-V, Low Power, Precision, CMOS, Rail-to-Rail Input/Output, Low Offset Voltage, Low Input Bias Current Op Amp

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9 Application and Implementation
OPA191, OPA2191, OPA4191
SBOS701A – DECEMEBER 2015 – REVISED APRIL 2016
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.
9.1 Application Information
The OPAx191 family offers outstanding dc precision and ac performance. These devices operate up to 36-V
supply rails and offer true rail-to-rail input/output, ultralow offset voltage and offset voltage drift, as well as
2-MHz bandwidth and high capacitive load drive. These features make the OPAx191 a robust, high-performance
operational amplifier for high-voltage industrial applications.
9.2 Typical Applications
9.2.1 Low-side Current Measurement
Figure 61 shows the OPA191 configured in a low-side current sensing application. For a full analysis of the
circuit shown in Figure 61 including theory, calculations, simulations, and measured data see the 0-1A, single-
supply, low-side, current sensing solutionTIPD129.
VCC
LOAD
ILOAD
RSHUNT
100m
5V
+ ^OPA191
±
LM7705
VOUT
RF
360k
RG 7.5k
Figure 61. OPA191 in a Low-Side, Current-Sensing Application
9.2.1.1 Design Requirements
The design requirements for this design are:
• Load current: 0 A to 1 A
• Output voltage: 4.9 V
• Maximum shunt voltage: 100 mV
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Product Folder Links: OPA191 OPA2191 OPA4191