Overview
The INA821ID from Texas Instruments is a high-precision instrumentation amplifier designed for low power consumption and wide supply voltage range. It features super-beta input transistors, which provide low input offset voltage, offset voltage drift, input bias current, and input voltage and current noise. The device can operate on a single supply from 4.5 V to 36 V or dual supplies up to ±18 V. It is available in 8-pin SOIC, VSSOP, and WSON packages and is specified over a temperature range of –40°C to +125°C. The INA821ID is optimized for high common-mode rejection ratio and low noise, making it suitable for various precision measurement applications.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Input Stage Offset Voltage (VOSI) | 10 | 35 | 40 | µV |
| Output Stage Offset Voltage (VOSO) | 50 | 350 | 400 | µV |
| Offset Voltage Drift | 0.1 | 0.4 | 5 | µV/°C |
| Noise (eNI) | 7 | nV/√Hz | ||
| Bandwidth (BW) | 4.7 MHz (G = 1), 290 kHz (G = 100) | |||
| Gain Range | 1 | 10,000 | V/V | |
| Common-Mode Rejection Ratio (CMRR) | 92 | dB | ||
| Power Supply Voltage (VS) | 4.5 | 36 | V (Single Supply), ±2.25 to ±18 V (Dual Supply) | |
| Quiescent Current (IQ) | 600 | 650 | 870 | µA |
| Operating Temperature Range | –40 | 125 | °C |
Key Features
- Low offset voltage: 10 µV (typ), 35 µV (max)
- Gain drift: 5 ppm/°C (G = 1), 35 ppm/°C (G > 1) (max)
- Noise: 7 nV/√Hz
- Bandwidth: 4.7 MHz (G = 1), 290 kHz (G = 100)
- Stable with 1-nF capacitive loads
- Inputs protected up to ±40 V
- High common-mode rejection ratio: 92 dB (G = 1)
- High power supply rejection ratio: 110 dB (G = 1)
- Low supply current: 650 µA (max)
- Wide supply range: Single-supply 4.5 V to 36 V, Dual-supply ±2.25 V to ±18 V
- Specified temperature range: –40°C to +125°C
- Available in 8-pin SOIC, VSSOP, and WSON packages
Applications
- Analog input modules
- Flow transmitters
- Battery testing
- LCD testing
- Electrocardiogram (ECG) equipment
- Surgical equipment
- Process analytics (pH, gas, concentration, force, and humidity)
Q & A
- What is the typical input offset voltage of the INA821ID?
The typical input offset voltage is 35 µV. - What is the maximum gain that can be set for the INA821ID?
The maximum gain that can be set is 10,000. - What is the bandwidth of the INA821ID at a gain of 1?
The bandwidth at a gain of 1 is 4.7 MHz. - What is the common-mode rejection ratio (CMRR) of the INA821ID at a gain of 1?
The CMRR exceeds 92 dB at a gain of 1. - What is the power supply range for the INA821ID?
The INA821ID can operate on a single supply from 4.5 V to 36 V or dual supplies up to ±18 V. - What is the quiescent current of the INA821ID?
The quiescent current is typically 650 µA. - What are the available packages for the INA821ID?
The INA821ID is available in 8-pin SOIC, VSSOP, and WSON packages. - What is the operating temperature range of the INA821ID?
The operating temperature range is –40°C to +125°C. - How is the gain set for the INA821ID?
The gain is set using a single external resistor connected between the gain setting pins (RG). - What kind of input protection does the INA821ID have?
The inputs are protected against overvoltage up to ±40 V.
