Analog Devices Inc. AD7124 Analog Front End (AFE) Portfolio

Analog Devices AD7124 Analog Front End (AFE) Portfolio features low power, low noise, completely integrated AFEs for high precision measurement applications. The devices contain a low noise, 24-bit sigma-delta (Σ-Δ) analog-to-digital converter (ADC). An on-chip low gain stage ensures that a small amplitude signal can be interfaced directly to the ADC. Developed with the highest degree of signal chain integration, the AD7124 AFEs provide a precision, low noise, low drift internal band gap reference. The devices also accept an external differential reference, which can be internally buffered.

Features

  • Three power modes
  • RMS noise
  • 24n Vrms at 1.17SPS, gain = 128 (255µA typical) low power
  • 20n Vrms at 2.34SPS, gain= 128 (355µA typical) mid power
  • 23n Vrms at 9.4SPS, gain= 128 (930µA typical) full power
  • Up to 22 noise-free bits in all power modes (gain = 1)
  • Output data rate
  • 9.38SPS to 19,200SPS full power
  • 2.34SPS to 4800SPS mid power
  • 1.17SPS to 2400SPS low power
  • Rail-to-rail analog inputs for gains > 1
  • Simultaneous 50Hz/60Hz rejection at 25SPS (single cycle settling)
  • Diagnostic functions (which aid safe integrity level (SIL) certification)
  • Crosspoint multiplexed analog inputs
  • Programmable gain (1 to 128)
  • Band gap reference with 15ppm/°C drift maximum (65µA)
  • Matched programmable excitation currents
  • Internal clock oscillator
  • On-chip bias voltage generator
  • Low-side power switch
  • General-purpose outputs
  • Multiple filter options
  • Internal temperature sensor
  • Self and system calibration
  • Sensor burnout detection
  • Automatic channel sequencer
  • Per channel configuration
  • 2.7V to 3.6V and ±1.8V power supply
  • Independent interface power supply
  • 5μA maximum power-down current
  • -40°C to +105°C temperature range
  • 32-lead LFCSP/24-lead TSSOP
  • 3-wire or 4-wire serial interface
  • SPI, QSPI™, MICROWIRE™, and DSP-compatible Schmitt trigger on SCLK
  • 4kV ESD

Applications

  • Temperature measurement
  • Pressure measurement
  • Industrial process control
  • Instrumentation
  • Smart transmitters
Published: 2018-08-15 | Updated: 2023-02-22