AD8421 Amplifier：Pinout, Datasheet, Schematic

AD8421Symbol

AD8421 Footprint

AD8421 3D Model

The AD8421 is a low cost, low power, extremely low noise, ultralow bias current, high-speed instrumentation amplifier that is ideally suited for a broad spectrum of signal conditioning and data acquisition applications. This product features extremely high CMRR, allowing it to extract low-level signals in the presence of high-frequency common-mode noise over a wide temperature range.

• Low power

• 2.3 mA maximum supply current

• Low noise

• 3.2 nV/√Hz maximum input voltage noise at 1 kHz

• 200 fA/√Hz current noise at 1 kHz

• Excellent ac specifications

• 10 MHz bandwidth (G = 1)

• 2 MHz bandwidth (G = 100)

• 0.6 μs settling time to 0.001% (G = 10)

• 80 dB CMRR at 20 kHz (G = 1)

• 35 V/μs slew rate

• High precision dc performance (AD8421BRZ)

• 94 dB CMRR minimum (G = 1)

• 0.2 μV/°C maximum input offset voltage drift

• 1 ppm/°C maximum gain drift (G = 1)

• 500 pA maximum input bias current

• Inputs protected to 40 V from opposite supply

• ±2.5 V to ±18 V dual supply (5 V to 36 V single supply)

• Gain set with a single resistor (G = 1 to 10,000)

• Medical instrumentation

• Precision data acquisition

• Microphone preamplification

• Vibration analysis

• Multiplexed input applications

• ADC driver

The AD8421 is based on the classic 3-op-amp topology. This topology has two stages: a preamplifier to provide differential amplification, followed by a difference amplifier that removes the common-mode voltage. A simplified schematic of the AD8421 is shown below.

AD8421 Schematic

AD8421 Package

Analog Devices is an international market leader in the design, production, and commercialization of a large range of high-performance integrated circuits (ICs) for analogue, mixed-signal, and digital signals (DSP) processing of almost all electronic systems. Since we started in 1965, the focus has been on the engineering challenge in electronic equipment related to signal to process. Our signal processing solutions, utilized by over 100,000 customers worldwide, play a key role in the conversion, conditioning, and processing of real-world events such as temperature, pressure, sonority, illumination, speed, and movement to electric signals for a wide range of electronic devices.