AD8429 Datasheet

• Low noise
  1 nV/√Hz input noise
  45 nV/√Hz output noise
• High accuracy dc performance (AD8429BRZ)
  90 dB CMRR minimum (G = 1)
  50 μV maximum input offset voltage
  0.02% maximum gain accuracy (G = 1)
• Excellent ac specifications
  80 dB CMRR to 5 kHz (G = 1)
  15 MHz bandwidth (G = 1)
  1.2 MHz bandwidth (G = 100)
  22 V/μs slew rate
  THD: −130 dBc (1 kHz, G = 1)
• Versatile
  ±4 V to ±18 V dual supply
  Gain set with a single resistor
  (G = 1 to 10,000)
• Temperature range for specified performance
  −40°C to +125°C

• Medical instrumentation
• Precision data acquisition
• Microphone preamplification
• Vibration analysis

The AD8429 is an ultralow noise, instrumentation amplifier designed for measuring extremely small signals over a wide temperature range (−40°C to +125°C).

The AD8429 excels at measuring tiny signals. It delivers ultralow input noise performance of 1 nV/√Hz. The high CMRR of the AD8429 prevents unwanted signals from corrupting the acqui-sition. The CMRR increases as the gain increases, offering high rejection when it is most needed. The high performance pin configuration of the AD8429 allows it to reliably maintain high CMRR at frequencies well beyond those of typical instrumentation amplifiers.

The AD8429 reliably amplifies fast changing signals. Its current feedback architecture provides high bandwidth at high gain, for example, 1.2 MHz at G = 100. The design includes circuitry to im-prove settling time after large input voltage transients. The AD8429 was designed for excellent distortion performance, allowing use in demanding applications such as vibration analysis.

Gain is set from 1 to 10,000 with a single resistor. A reference pin allows the user to offset the output voltage. This feature can be useful to shift the output level when interfacing to a single supply signal chain. The AD8429 performance is specified over the extended industrial temperature range of −40°C to +125°C. It is available in an 8-lead plastic SOIC package.