16-Channel DAS with 14-Bit, Bipolar Input, Dual Simultaneous Sampling ADC

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

The input clamp protection circuitry can tolerate voltages up to ±21 V. The AD7617 has 1 MΩ 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 2.5 V reference and reference buffer, and high speed serial and parallel interfaces. The AD7617 is serial peripheral interface (SPI)/QSPI™/DSP/MICROWIRE compatible.

Applications

* Power line monitoring

* Protective relays

* Multiphase motor control

* Instrumentation and control systems

* Data acquisition systems (DASs)

* 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