Texas Instruments INA Series Instrumentation Amplifiers are available at Mouser Electronics. Mouser offers inventory, pricing, & datasheets for Texas. The INA is a low power, general purpose instru- mentation amplifier offering excellent accuracy. Its versatile 3-op amp design and small size make it ideal. Texas Instruments INA Linear – Amplifiers – Instrumentation, OP Amps, Buffer Amps parts available at DigiKey.
|Published (Last):||2 August 2016|
|PDF File Size:||5.23 Mb|
|ePub File Size:||5.27 Mb|
|Price:||Free* [*Free Regsitration Required]|
The contribution of R G ina118 gain ina118 and drift can be directly inferred inna118 Equation 1. Low resistor values required for high gain can make wiring resistance important.
This is a result of its current-feedback topology and is not an indication of instability. Information in the following applications sections ina118 not part of the TI component specification, and Ina118 does not ina118 its accuracy or completeness.
As shown in Equation 1the gain of the INA is set by connecting a single external resistor, R Gconnected between pins 1 and 8. iina118
Optional Trimming of Output Offset Voltage. The INA measures a small differential voltage with a ina118 common-mode voltage developed between the ina118 and inverting input.
INA Precision, Low Power Instrumentation Amplifier |
Customers should validate and test their design implementation to confirm system functionality. Ina118 inherent common-mode rejection of instrumentation amplifiers enables accurate measurements even in the presence of ground loop potentials. Input circuitry must provide ina118 path for this input bias current for proper operation. Figure ina118 shows the basic connections required for operation of the INA The output is referred to the ina118 reference Ref terminal, which is normally grounded.
The voltage applied to the Ref terminal is ins118 at the output. This must be a low-impedance connection to assure ina118 common-mode rejection. A simple pole at kHz or lower produces a flat passband unity gain response. Because industrial process control systems often involve ina18 interconnecting jna118 multiple subsystems, ground loops are frequently encountered and often ina118 not easily solved.
The Figure 1 shows that, despite its low quiescent current, the INA achieves wide bandwidth, even at high gain. However, a path ina118 be provided for the input bias current of both inputs. Applications with noisy or high impedance power supplies may require decoupling capacitors close to the device pins as shown.
If the differential ina118 resistance is ina118, the bias current return path can ina118 connected to one input ina118 the thermocouple example in Figure The accuracy and temperature coefficient of these resistors are included in the gain accuracy and drift specifications of the INA Ina118 higher source impedance, using two equal resistors provides ina118 balanced input, with the possible advantages of lower input offset voltage due to bias current, and better high-frequency common-mode rejection.
Commonly used gains ina118 resistor values are shown in Figure Ina118 INA is laser-trimmed for low offset voltage and drift. Figure 26 depicts an input signal with ina118 5-mV, 1-kHz signal with a ina18 common-mode signal, a condition often observed in process control systems. Figure ina118 and Figure 29 depict the performance of a typical application of the INA in a shop floor vibration sensing application.
Without a bias current path, ina118 inputs float to a potential which exceeds the common-mode ina118 of the INA, and the input amplifiers saturates. The stability and ina118 drift of the external gain setting resistor, R Galso affects gain. The op una118 buffer provides low impedance at the Ref terminal to preserve good common-mode rejection.
Sockets add to the wiring resistance, which contributes additional gain error possibly an unstable gain error in gains of approximately or greater.
Figure 27 ina118 an optional circuit for trimming the output offset voltage. These on-chip metal film resistors are laser-trimmed to accurate absolute ina118.
INA データシート 高精度、低消費電力、計測アンプ |
The high common-mode rejection makes the INA suitable for a wide range ina118 applications. Figure 28 shows various ina118 for an input bias current path. Most applications require no ina118 offset adjustment. Settling time also remains excellent at high gain. This is due to the current-feedback topology of the INA The typical application was tested in a system ina118 these requirements: The ability to set the reference pin to adjust the functionality ina118 the output signal offers additional flexibility that is practical for multiple configurations.
High input impedance means that this input bias current changes very little with varying input voltage.