Overview
The INA326EA/250G4, produced by Texas Instruments, is a high-performance, low-cost, precision instrumentation amplifier. It features rail-to-rail input and output, making it suitable for a wide range of applications from general-purpose to high-accuracy. This amplifier is known for its excellent long-term stability, very low 1/f noise, and low offset voltage and drift. The INA326EA/250G4 operates on a single supply voltage and is available in an MSOP-8 package, specified over the industrial temperature range of –40°C to +85°C, with operation extending to +125°C.
Key Specifications
| Parameter | Condition | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Supply Voltage | +2.7 | +5.5 | V | ||
| Input Offset Voltage, RTI | VS = +5V, VCM = VS/2 | ±20 | ±100 | µV | |
| Input Impedance, Differential | 10^10 || 2 Ω || pF | ||||
| Input Impedance, Common-Mode | 10^10 || 14 Ω || pF | ||||
| Bandwidth, –3dB | G = 1 to 1k | 1 kHz | |||
| Slew Rate | VS = +5V, All Gains, CL = 100pF | V/µs | |||
| Quiescent Current | IO = 0, Diff VIN = 0V, VS = +5V | 2.4 | 3.4 | mA | |
| Operating Temperature Range | –40°C | +125°C | °C |
Key Features
- Precision Low Offset: The INA326EA/250G4 has a low input offset voltage and drift, ensuring high accuracy over time and temperature.
- Rail-to-Rail Input and Output: The amplifier can process input signals that extend beyond the positive and negative power-supply rails, making it highly versatile.
- High Common-Mode Rejection Ratio (CMRR): The unique internal topology of the INA326EA/250G4 provides excellent CMRR without the need for accurately matched resistors.
- Low Noise: The amplifier features low 1/f noise and high-frequency noise performance, making it suitable for sensitive applications.
- Input Protection: The inputs are protected by internal diodes connected to the power-supply rails, preventing damage from input signals that exceed the power supplies.
- Flexible Gain Setting: The gain can be set using external resistors (R1 and R2), allowing for a wide range of gain configurations.
Applications
The INA326EA/250G4 is suitable for a variety of applications, including:
- General-Purpose Instrumentation: Ideal for everyday measurement and monitoring tasks.
- High-Accuracy Measurements: Suitable for applications requiring precise signal amplification, such as in medical devices, industrial control systems, and scientific instruments.
- Thermocouple Amplification: Can be used to amplify signals from thermocouples, taking advantage of its high CMRR and low noise characteristics.
- Analog-to-Digital Conversion Pre-Amplification: The output filter can serve as an anti-aliasing filter ahead of an A/D converter.
Q & A
- What is the supply voltage range for the INA326EA/250G4?
The supply voltage range is from +2.7V to +5.5V.
- What is the typical input offset voltage of the INA326EA/250G4?
The typical input offset voltage is ±100 µV at VS = +5V and VCM = VS/2.
- What is the bandwidth of the INA326EA/250G4?
The bandwidth is 1 kHz for gains from 1 to 1000.
- How is the gain set for the INA326EA/250G4?
The gain is set using external resistors R1 and R2, with the overall gain described by the equation G = 2 * (R2/R1).
- What is the common-mode rejection ratio (CMRR) of the INA326EA/250G4?
The CMRR is excellent due to the unique internal topology, which does not rely on accurately matched resistors.
- What is the operating temperature range of the INA326EA/250G4?
The operating temperature range is from –40°C to +125°C.
- Does the INA326EA/250G4 have input protection?
Yes, the inputs are protected by internal diodes connected to the power-supply rails.
- Can the INA326EA/250G4 be used in single-supply applications?
Yes, it can be used in single-supply applications, but this may require adjusting the gain-setting resistors to ensure full output swing.
- What is the quiescent current of the INA326EA/250G4?
The quiescent current is typically 3.4 mA at VS = +5V.
- Is the INA326EA/250G4 suitable for battery-operated applications?
While the INA326EA/250G4 itself does not have a shutdown feature, the INA327 variant includes an enable/shutdown function that can significantly reduce power consumption in battery-operated applications).
