Overview
The AD8421ARZ-RL, produced by Analog Devices Inc., is a low-cost, low-power, extremely low-noise, ultra-low bias current, high-speed instrumentation amplifier. It is ideally suited for a broad spectrum of signal conditioning and data acquisition applications. The AD8421 features high common-mode rejection ratio (CMRR), making it capable of extracting low-level signals in the presence of high-frequency common-mode noise over a wide temperature range.
Key Specifications
| Parameter | Unit | Min | Typ | Max |
|---|---|---|---|---|
| Supply Voltage | V | ±2.5 to ±18 (dual), 5 to 36 (single) | ||
| Input Voltage Noise | nV/√Hz | 3.2 | ||
| Input Bias Current | pA | 500 | ||
| CMRR (G = 1) | dB | 80 | 94 | |
| Bandwidth (G = 1) | MHz | 10 | ||
| Settling Time to 0.001% (G = 10) | µs | 0.6 | ||
| Slew Rate | V/µs | 35 | ||
| Input Offset Voltage Drift | µV/°C | 0.2 | ||
| Gain Drift (G = 1) | ppm/°C | 1 | ||
| Operating Temperature Range | °C | −40 to +85 (MSOP, SOIC), −40 to +125 (LFCSP) |
Key Features
- Low power consumption with a maximum supply current of 2.3 mA
- Extremely low noise: 3.2 nV/√Hz input voltage noise and 200 fA/√Hz current noise at 1 kHz
- High speed: 10 MHz bandwidth (G = 1), 2 MHz bandwidth (G = 100), and 0.6 µs settling time to 0.001% (G = 10)
- High CMRR: 80 dB to 20 kHz (G = 1) and 94 dB minimum (G = 1)
- High precision DC performance: 0.2 µV/°C maximum input offset voltage drift and 1 ppm/°C maximum gain drift (G = 1)
- Inputs protected to 40 V from opposite supply rail
- Gain set with a single resistor (G = 1 to 10,000)
- Available in 8-lead LFCSP, 8-lead MSOP, and 8-lead SOIC packages
Applications
- Medical instrumentation
- Precision data acquisition
- Microphone preamplification
- Vibration analysis
- Multiplexed input applications
- ADC driver
Q & A
- What is the typical input voltage noise of the AD8421?
The AD8421 has a typical input voltage noise of 3.2 nV/√Hz at 1 kHz.
- What is the maximum input bias current of the AD8421?
The maximum input bias current is 500 pA.
- What is the CMRR of the AD8421 at G = 1?
The CMRR at G = 1 is 80 dB to 20 kHz, with a minimum of 94 dB.
- What is the bandwidth of the AD8421 at G = 1 and G = 100?
The bandwidth is 10 MHz at G = 1 and 2 MHz at G = 100.
- How is the gain set in the AD8421?
The gain is set with a single resistor and can range from 1 to 10,000.
- What are the available package types for the AD8421?
The AD8421 is available in 8-lead LFCSP, 8-lead MSOP, and 8-lead SOIC packages.
- What is the operating temperature range for the AD8421 in different packages?
The operating temperature range is −40°C to +85°C for MSOP and SOIC packages, and −40°C to +125°C for the LFCSP package.
- What are some typical applications of the AD8421?
Typical applications include medical instrumentation, precision data acquisition, microphone preamplification, vibration analysis, multiplexed input applications, and ADC driver.
- Does the AD8421 have any special versions for defense and aerospace applications?
Yes, the AD8421-EP supports defense and aerospace applications with a military temperature range (−55°C to +125°C) and other enhanced features.
- How is the input protection of the AD8421?
The inputs are protected to 40 V from the opposite supply rail.
