Overview
The AD8421ARMZ-R7, produced by Analog Devices Inc., is a low-cost, low-power, high-speed instrumentation amplifier. It is designed to offer extremely low noise, ultralow bias current, and high precision dc performance, making it ideal for a broad range of signal conditioning and data acquisition applications. This amplifier is particularly suited for applications requiring high channel count and multiplexed systems, such as medical instrumentation, precision data acquisition, and vibration analysis.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Bandwidth (G = 1) | - | 10 | - | MHz |
| Bandwidth (G = 100) | - | 2 | - | MHz |
| Settling Time to 0.001% (G = 10) | - | 0.6 | - | µs |
| Settling Time to 0.001% (G = 100) | - | 0.8 | - | µs |
| CMRR at 20 kHz (G = 1) | 80 | - | - | dB |
| Slew Rate | - | 35 | - | V/µs |
| Input Voltage Noise at 1 kHz | - | 3.2 | - | nV/√Hz |
| Input Bias Current | - | 500 | - | pA |
| Input Offset Voltage Drift | - | 0.2 | - | µV/°C |
| Gain Drift (G = 1) | - | 1 | - | ppm/°C |
| Supply Voltage Range | ±2.5 | - | ±18 | V |
| Supply Current | - | 2.3 | - | mA |
| Operating Temperature Range | -40 | - | 85 | °C |
| Package Type | - | 8-Lead MSOP | - | - |
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 performance: 10 MHz bandwidth at G = 1 and 2 MHz bandwidth at G = 100.
- Fast settling time: 0.6 µs to 0.001% at G = 10.
- High common-mode rejection ratio (CMRR): 80 dB at 20 kHz (G = 1) and 94 dB minimum (G = 1).
- Ultralow bias current: 500 pA maximum.
- High precision dc performance with low input offset voltage drift (0.2 µV/°C) and low gain drift (1 ppm/°C).
- Input protection up to 40 V from the opposite supply rail.
- Gain adjustable with a single resistor from 1 to 10,000.
- Reference pin for precise output voltage offset.
Applications
- Medical instrumentation.
- Precision data acquisition.
- Microphone preamplification.
- Vibration analysis.
- Multiplexed input applications.
- ADC driver.
Q & A
- What is the bandwidth of the AD8421 at a gain of 1?
The bandwidth of the AD8421 at a gain of 1 is 10 MHz. - What is the settling time of the AD8421 to 0.001% at a gain of 10?
The settling time of the AD8421 to 0.001% at a gain of 10 is 0.6 µs. - What is the common-mode rejection ratio (CMRR) of the AD8421 at 20 kHz and a gain of 1?
The CMRR of the AD8421 at 20 kHz and a gain of 1 is 80 dB. - What is the maximum input bias current of the AD8421?
The maximum input bias current of the AD8421 is 500 pA. - What is the input voltage noise of the AD8421 at 1 kHz?
The input voltage noise of the AD8421 at 1 kHz is 3.2 nV/√Hz. - What is the operating temperature range for the AD8421 in the 8-lead MSOP package?
The operating temperature range for the AD8421 in the 8-lead MSOP package is from -40°C to +85°C. - How is the gain of the AD8421 adjusted?
The gain of the AD8421 is adjusted using a single resistor, allowing gains from 1 to 10,000. - What is the maximum supply voltage for the AD8421?
The maximum supply voltage for the AD8421 is ±18 V (or 5 V to 36 V single supply). - What kind of input protection does the AD8421 offer?
The AD8421 offers input protection up to 40 V from the opposite supply rail. - What are some typical applications of the AD8421?
Typical applications include medical instrumentation, precision data acquisition, microphone preamplification, vibration analysis, and multiplexed input applications.
