Datasheet AD7609 (Analog Devices) - 4

Data Sheet AD7609 GENERAL DESCRIPTION
The AD7609 is an 18-bit, 8-channel, true differential, The AD7609 operates from a single 5 V supply and can simultaneous sampling analog-to-digital data acquisition accommodate ±10 V and ±5 V true bipolar differential input system (DAS). The part contains analog input clamp protection, signals while sampling at throughput rates up to 200 kSPS for a second-order antialiasing filter, a track-and-hold amplifier, an all channels. The input clamp protection circuitry can tolerate 18-bit charge redistribution successive approximation analog- voltages up to ±16.5 V. The AD7609 has 1 MΩ analog input to-digital converter (ADC), a flexible digital filter, a 2.5 V impedance regardless of sampling frequency. The single supply reference and reference buffer, and high speed serial and operation, on-chip filtering, and high input impedance elimi- parallel interfaces. nate the need for driver op amps and external bipolar supplies. The AD7609 antialiasing filter has a −3 dB cutoff frequency of 32 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. Rev. B | Page 3 of 36 Document Outline Features Applications Companion Products Functional Block Diagram Table of Contents Revision History General Description Specifications Timing Specifications Timing Diagrams Absolute Maximum Ratings Thermal Resistance ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Terminology Theory of Operation Converter Details Analog Input Analog Input Ranges Analog Input Impedance Analog Input Clamp Protection Analog Input Antialiasing Filter Track-and-Hold Amplifiers ADC Transfer Function Internal/External Reference External Reference Mode Internal Reference Mode Typical Connection Diagram Power-Down Modes Conversion Control Simultaneous Sampling on All Analog Input Channels Simultaneously Sampling Two Sets of Channels Digital Interface Parallel Interface (/PAR/SER SEL = 0) Serial Interface (/PAR/SER SEL = 1) Reading During Conversion Digital Filter Layout Guidelines Outline Dimensions Ordering Guide