New Industry Products

14-Bit DAS for Power Line Monitoring and Multi-phase Motor Control

August 15, 2017 by Paul Shepard

Analog Devices has added the AD7617, a 14-bit DAS that supports dual simultaneous sampling of 16 channels. The AD7617 operates from a single +5V supply and can accommodate ±10V, ±5V, and ±2.5V true bipolar input signals while sampling at throughput rates up to 1 MSPS per channel pair with 85dB signal-to-noise ratio (SNR).

Higher SNR performance can be achieved with the on-chip oversampling mode (85.3 dB for an oversampling ratio (OSR) of 2). Applications are expected to include power line monitoring, protective relays, multiphase motor control, instrumentation and control systems and data acquisition systems (DASs).

The input clamp protection circuitry can tolerate voltages up to ±21V. The AD7617 has 1MΩ analog input impedance, regardless of sampling frequency. The single-supply operation, on-chip filtering, and high input impedance eliminate the need for driver op amps and external bipolar supplies.

The device contains analog input clamp protection, a dual, 14-bit charge redistribution successive approximation register (SAR) analog-to-digital converter (ADC), a flexible digital filter, a 2.5V reference and reference buffer, and high speed serial and parallel interfaces. The AD7617 is serial peripheral interface (SPI)/QSPI™/DSP/MICROWIRE compatible.

Features and benefits include:

  • 16-channel, dual, simultaneously sampled inputs
  • Independently selectable channel input ranges
    • True bipolar: ±10 V, ±5 V, ±2.5 V
  • Single 5 V analog supply and 2.3 V to 3.6 V VDRIVE supply
  • Fully integrated data acquisition solution
    • Analog input clamp protection
    • Input buffer with 1 MΩ analog input impedance
    • First-order antialiasing analog filter
    • On-chip accurate reference and reference buffer
    • Dual 14-bit SAR ADC
    • Throughput rate: 2× 1 MSPS per channel pair
    • Oversampling capability with digital filter
    • Flexible sequencer with burst mode
  • Flexible parallel/serial interface
    • SPI/QSPI/MICROWIRE/DSP compatible
    • Optional CRC error checking
  • Hardware/software configuration
  • Performance
    • 85.3 dB typical SNR at 500 kSPS (2× oversampling)
    • 85 dB typical SNR at 1 MSPS
    • −103 dB typical THD at ±10 V range
    • ±0.3 LSB INL (typical), ±0.99 LSB DNL (maximum)
    • 8 kV ESD analog input pins only
  • On-chip self detect function
  • 80-lead LQFP package