Texas Instruments Ina128ua/2k5 Datasheet

In the complex circuits of electronic devices, amplifiers play a crucial role, especially in application scenarios where high signal precision and stability are required. The INA128UA/2K5 (https://www.sic-components.com/product/product?product_id=300998) precision instrumentation amplifier introduced by Texas Instruments stands out among numerous electronic components with its excellent performance, becoming an ideal choice for engineers when designing high-precision signal conditioning circuits.​

I. Outstanding Performance Characteristics​
(1) High-Precision Indicators​
Low Offset Voltage: The maximum offset voltage of the INA128UA/2K5 is only 50 μV. This means that the initial error introduced by the amplifier itself during the signal amplification process is extremely small. For example, in precision measurement circuits, the tiny offset voltage ensures that the weak signals collected by sensors remain highly accurate after amplification, without significant deviations caused by the amplifier's errors, thus providing a reliable basis for subsequent data processing.​
Low Drift: Its drift is as low as 0.5 μV/°C (maximum). In practical applications, the ambient temperature often changes, and the low-drift characteristic ensures the stability of the amplifier's output signal under different temperature conditions. For instance, in industrial automation control systems, even if the equipment operates for a long time in a workshop environment with large temperature fluctuations, the INA128UA/2K5 can still stably amplify various sensor signals, ensuring precise control of the system.​
High Common-Mode Rejection Ratio (CMRR): The minimum CMRR of this amplifier is 120 dB. The high CMRR enables it to effectively suppress common-mode signals. That is, when the same interference signals appear at both input terminals simultaneously, the amplifier can greatly reduce the impact of such interference on the output signal. In the bioelectrical signal acquisition systems of medical devices, there are various electromagnetic interferences around the human body. With its high CMRR, the INA128UA/2K5 can clearly extract weak bioelectrical signals, such as electrocardiogram and electroencephalogram signals, while suppressing common-mode interference signals to an extremely low level.​
(2) Low-Power Advantage​
The quiescent current of the INA128UA/2K5 is only 700 μA. In today's trend of advocating energy conservation and environmental protection, the low-power characteristic not only helps to extend the battery life of battery-powered devices but also reduces the overall power consumption of the system and the heat dissipation requirements. For example, in battery-powered applications such as portable medical monitoring devices and wireless sensor nodes, the low-power characteristic of the INA128UA/2K5 enables the devices to operate continuously for a longer time with limited battery capacity, improving the convenience and reliability of device use.​
(3) Wide Power Supply Voltage Range and Input Protection​
Wide Power Supply Voltage Range: Its power supply voltage range is ±2.25V to ±18V, enabling this amplifier to adapt to a variety of different power supply systems. Whether in some small electronic devices powered by low voltage or in industrial equipment that requires higher voltage drive, the INA128UA/2K5 can operate stably, providing great flexibility for different application scenarios.​
Input Protection: The input protection voltage can reach ±40V. In actual circuits, overvoltage conditions may occur at the input terminals for various reasons, such as electrostatic discharge and power surges. The input protection function of the INA128UA/2K5 can effectively prevent these overvoltages from damaging the internal circuits of the amplifier, improving the reliability and stability of the amplifier in complex electromagnetic environments and reducing the risks in circuit design.​

II. Unique Working Principle​
The INA128UA/2K5 adopts a multi-functional three-stage operational amplifier design and a current feedback input circuit. The current feedback input circuit enables the amplifier to provide a wide bandwidth even at high gains (e.g., 200 kHz, G = 100). Users can flexibly set any gain within the range of 1 to 10,000 through a single external resistor. Specifically, the gain setting of this amplifier follows the industry's common gain formula, and its internal circuit structure can accurately adjust the amplification factor according to the change of the external resistor, achieving precise amplification of signals with different amplitudes. This design not only ensures the performance stability of the amplifier under different gain settings but also provides convenience for users to flexibly adjust the signal amplification factor according to specific requirements in practical applications.​

III. Extensive Application Areas​
(1) Industrial Control Field​
Sensor Signal Amplification: In the industrial production process, various sensors are used to monitor physical quantities such as temperature, pressure, and flow. The INA128UA/2K5 can perform high-precision amplification of the weak electrical signals output by these sensors, providing accurate signal inputs for the control system. For example, in chemical production, after the signals output by pressure sensors are amplified by the INA128UA/2K5, the control system can monitor the pressure changes in pipelines in real-time and accurately, thus ensuring the safe and stable production process.​
Motor Drive Control: In motor drive systems, it is necessary to accurately monitor and amplify the current and voltage signals of the motor to achieve precise control of the motor's operating status. The INA128UA/2K5 can be used to amplify these feedback signals, helping the control system to timely adjust parameters such as the motor's speed and torque, improving the efficiency and reliability of the motor drive system.​
(2) Medical Equipment Field​
Bioelectrical Signal Detection: As mentioned above, in medical devices such as electrocardiographs and electroencephalographs, the INA128UA/2K5 can effectively amplify extremely weak bioelectrical signals while suppressing electromagnetic interference in the surrounding environment, providing doctors with clear and accurate bioelectrical signal patterns to assist in disease diagnosis.​
Medical Monitoring Equipment: In portable medical monitoring equipment, such as dynamic electrocardiogram monitors and blood glucose monitors, the low-power and high-precision characteristics of the INA128UA/2K5 make it an ideal choice for signal amplification. It can operate with low power during long-term monitoring, ensuring the equipment's battery life, and accurately amplify physiological parameter signals, ensuring the reliability of monitoring data.​
(3) Data Acquisition Systems​
In data acquisition systems, it is necessary to collect and preprocess signals from various sensors. The INA128UA/2K5 can perform high-quality amplification of sensor signals, ensuring that the collected data has high precision and reliability. For example, in environmental monitoring data acquisition systems, after the sensor signals used to detect parameters such as air quality and water quality are amplified by the INA128UA/2K5, they can be accurately collected and transmitted to the data processing center, providing reliable data support for environmental monitoring and analysis.​

IV. Packaging Forms and Temperature Adaptability​
The INA128UA/2K5 is available in 8-pin plastic DIP and SO-8 surface-mount packages. The 8-pin plastic DIP package has good mechanical strength and electrical performance, making it suitable for use in occasions where high requirements are placed on the installation firmness of components. The SO-8 surface-mount package, on the other hand, has the advantages of occupying less circuit board space and being easy to achieve automated production, making it suitable for application scenarios with limited circuit board space and a pursuit of miniaturized design. In addition, the rated temperature range of this amplifier is –40°C to +125°C, enabling it to operate normally in relatively harsh temperature environments. Whether in cold outdoor environments or high-temperature industrial production workshops, the INA128UA/2K5 can stably perform its signal amplification function, ensuring the normal operation of the equipment.​

In conclusion, the INA128UA/2K5 precision instrumentation amplifier from Texas Instruments occupies an important position in the electronic components market with its outstanding performance, unique working principle, extensive application areas, and good packaging forms and temperature adaptability. It provides reliable solutions for numerous applications with strict requirements for signal precision and stability and is a key component trusted by electronics engineers in circuit design. With the continuous development of electronic technology, it is believed that the INA128UA/2K5 will play an important role in more innovative applications, promoting the development of electronic devices towards higher performance, lower power consumption, and smaller size.​



Products: https://www.sic-components.com/product/product?product_id=300998
Datasheet: https://www.ti.com/lit/ds/symlink/ina128.pdf?ts=1750758875288&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FINA128%252Fpart-details%252FINA128UA%252F2K5