Analog Devices Inc. EVAL-AD7718EBZ

Overview

EVAL-AD7718EBZ from Analog Devices is a fully featured evaluation board for the AD7718 - an 8/10-channel, 24-bit sigma-delta ADC with on-chip programmable gain, digital filtering, and factory calibration. It supports analog input ranges from transducer-level signals, uses dual on-board AD780 2.5 V references, and interfaces via PC parallel port using bundled Windows software for register control, multi-channel sampling, and noise analysis.

For engineers reviewing the EVAL-AD7718EBZ datasheet, EVAL-AD7718EBZ pinout, EVAL-AD7718EBZ application, or EVAL-AD7718EBZ equivalent, this board enables rapid functional validation of the AD7718 in low-frequency precision measurement systems - including configuration of filter update rate, channel selection, reference sourcing, I/O pin control, and system-level calibration without custom hardware.

Technical Context

The EVAL-AD7718EBZ implements direct interface to the AD7718's serial 3-wire (SCLK/DIN/DOUT) and control (CS/RESET/SYNC/RDY) signals via buffered digital buffers (74HC4050N, 74ACT244), ensuring signal integrity between PC and IC. It provides configurable analog input routing through 15 link options (LK1–LK15) for AIN1–AIN8, AINCOM, REFIN1(±), REFIN2(±), AIN9/AIN10, and XTAL1 clock source selection.

Power architecture separates analog (AVDD/AGND) and digital (DVDD/DGND) domains with dedicated decoupling: 10 µF tantalum + 0.1 µF ceramic at AVDD/DVDD inputs and near U1; AGND and DGND are joined only at the AD7718 GND pin to minimize noise coupling. The board ships with default link settings enabling immediate use with on-board 32.768 kHz crystal and dual AD780 references.

Key Specifications

Availability

EVAL-AD7718EBZ is available at Aetrix Electronics and suitable for precision sensor interface validation, industrial process monitoring, weigh-scale development, and medical instrumentation prototyping requiring stable component supply and traceable evaluation hardware.

Supply support for EVAL-AD7718EBZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Wilmington, MA, with design centers worldwide.

The EVAL-AD7718EBZ belongs to Analog Devices' precision data acquisition evaluation platform family, designed specifically to accelerate development of low-frequency, high-resolution measurement systems using their sigma-delta ADCs.

FAQ

What is the primary function of the EVAL-AD7718EBZ?

The EVAL-AD7718EBZ is a dedicated evaluation board for the AD7718 24-bit sigma-delta ADC. It enables engineers to configure, test, and validate the full functionality of the AD7718 - including channel selection, gain setting, digital filter tuning, reference sourcing, calibration, and I/O control - using included Windows software and standardized PC connectivity. The EVAL-AD7718EBZ does not replace the AD7718 but serves as its complete hardware interface and control environment.

Does the EVAL-AD7718EBZ support external reference voltages?

Yes, the EVAL-AD7718EBZ supports external reference voltages via dedicated SMB sockets: SKT10 and SKT11 for REFIN2(+)/AIN9 and REFIN2(−)/AIN10; SKT12 and SKT13 for REFIN1(+) and REFIN1(−). Link options LK10–LK13 must be set to position "B" to route external signals to these pins. Default configuration uses on-board AD780 references, confirmed in Table 1 of the board documentation.

How is the EVAL-AD7718EBZ powered?

The EVAL-AD7718EBZ requires two independent power supplies: +5 V applied between AVDD and AGND for analog circuitry (including AD7718 core and references), and DVDD/DGND for digital buffers. AVDD and DVDD are decoupled separately using 10 µF tantalum + 0.1 µF ceramic capacitors - at board input and adjacent to U1 and buffer ICs. AGND and DGND are internally joined only at the AD7718 GND pin, per design guidance to prevent ground-loop noise.

Which PC interface does the EVAL-AD7718EBZ use?

The EVAL-AD7718EBZ interfaces to a Windows PC via a standard parallel (Centronics) printer port using connector J1 and a 36-pin cable. Software communicates with the AD7718 through buffered SCLK, DIN, DOUT, CS, and RDY signals. A secondary 9-pin D-sub (J4) is provided for non-PC system interfacing, maintaining identical signal buffering and logic levels as J1.

Can the EVAL-AD7718EBZ evaluate both main and auxiliary ADC channels of the AD7718?

Yes, the EVAL-AD7718EBZ fully supports both the main and auxiliary ADC channels of the AD7718. Its bundled software includes a Multi-Channel Test screen that allows independent configuration of update rate, polarity, and range per channel, and displays real-time hex codes for all enabled inputs. The RDY pin behavior - reflecting readiness of either ADC - is implemented and monitored directly on the board, confirming dual-channel operation capability.