8-Channel DAS with 18-Bit, Bipolar, Simultaneous Sampling ADC

The AD7608 is an 18-bit, 8-channel simultaneous sampling, analog-to-digital data acquisition system (DAS). The part contains analog input clamp protection, a second-order antialiasing filter, a track-and-hold amplifier, an 18-bit charge redistribution successive approximation 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 AD7608 operates from a single 5 V supply and can accommodate ±10 V and ±5 V true bipolar input signals while sampling at throughput rates up to 200 kSPS for all channels.

The input clamp protection circuitry can tolerate voltages up to ±16.5 V. The AD7608 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 AD7608 antialiasing filter has a 3 dB cutoff frequency of 22 kHz and provides 40 dB antialias rejection when sampling at 200 kSPS. The flexible digital filter is pin driven, yields improvements in SNR, and reduces the 3 dB bandwidth.

Applications

* Power line monitoring and protection systems

* Multiphase motor controls

* Instrumentation and control systems

* Multiaxis positioning systems

* Data acquisition systems (DAS)

* 8 simultaneously sampled inputs

* True bipolar analog input ranges: ±10 V, ±5 V

* Single 5 V analog supply and 2.3 V to 5.25 V VDRIVE

* Fully integrated data acquisition solution

* Analog input clamp protection

* Input buffer with 1 MΩ analog input impedance

* Second-order antialiasing analog filter

* On-chip accurate reference and reference buffer

* 18-bit ADC with 200 kSPS on all channels

* Oversampling capability with digital filter