Overview
The INA121UA/2K5, produced by Texas Instruments, is a FET-input, low power instrumentation amplifier known for its excellent accuracy and versatility. This amplifier features a three-op amp design and is available in compact 8-pin DIP and SO-8 surface mount packages. It is ideal for a variety of general purpose applications, particularly those requiring high impedance sources and low power consumption. The INA121UA/2K5 operates on a wide supply range from ±2.25V to ±18V, making it suitable for battery-operated and single 5V systems. Its low quiescent current of ±450µA and low input bias current of ±4pA enhance its efficiency and accuracy in various settings.
Key Specifications
| Parameter | Min | Typ | Max | Units |
|---|---|---|---|---|
| Input Offset Voltage, RTI | ±200 | ±200 | ±500 | µV |
| Input Offset Drift | ±2 | ±2 | ±5 | µV/°C |
| Common-Mode Rejection (G = 100) | 96 | 106 | 90 | dB |
| Input Noise (f = 1kHz, G = 100) | 20 | 20 | - | nV/√Hz |
| Supply Voltage Range | ±2.25 | - | ±18 | V |
| Quiescent Current | ±450 | ±450 | ±525 | µA |
| Operating Temperature Range | -40 | - | 85 | °C |
| Input Protection | - | - | ±40 | V |
Key Features
- Low bias current: ±4pA
- Low quiescent current: ±450µA
- Low input offset voltage: ±200µV
- Low input offset drift: ±2µV/°C
- Low input noise: 20nV/√Hz at f = 1kHz (G = 100)
- High common-mode rejection ratio (CMRR): 106dB at G = 100
- Wide supply range: ±2.25V to ±18V
- Low nonlinearity error: 0.001% max
- Input protection to ±40V
- Available in 8-pin DIP and SO-8 surface mount packages
Applications
- Low-level transducer amplifiers (bridge, RTD, thermocouple)
- Physiological amplifiers (ECG, EEG, EMG, respiratory)
- High impedance transducers
- Capacitive sensors
- Multi-channel data acquisition
- Portable, battery-operated systems
- General purpose instrumentation
Q & A
- What is the input offset voltage of the INA121UA/2K5? The input offset voltage is ±200µV.
- What is the common-mode rejection ratio (CMRR) of the INA121UA/2K5 at a gain of 100? The CMRR is 106dB at G = 100.
- What is the quiescent current of the INA121UA/2K5? The quiescent current is ±450µA.
- What is the input noise of the INA121UA/2K5 at 1kHz and a gain of 100? The input noise is 20nV/√Hz.
- What is the supply voltage range for the INA121UA/2K5? The supply voltage range is ±2.25V to ±18V.
- How is the gain of the INA121UA/2K5 set? The gain is set by connecting a single external resistor, RG, between pins 1 and 8.
- What is the operating temperature range of the INA121UA/2K5? The operating temperature range is -40°C to 85°C.
- Does the INA121UA/2K5 have input protection? Yes, it has input protection up to ±40V.
- In what packages is the INA121UA/2K5 available? It is available in 8-pin DIP and SO-8 surface mount packages.
- What are some typical applications of the INA121UA/2K5? Typical applications include low-level transducer amplifiers, physiological amplifiers, high impedance transducers, capacitive sensors, multi-channel data acquisition, and portable, battery-operated systems.
