Analog Devices Inc. EVAL-AD7621CBZ

Overview

EVAL-AD7621CBZ from Analog Devices is an evaluation board designed for the AD7621 16-bit, 3MSPS PulSAR® successive approximation register (SAR) analog-to-digital converter. It provides buffered parallel (16-bit wide) and serial interfaces, on-board precision reference (AD780/ADR431/ADR435), clock oscillator, analog signal conditioning circuitry, and supports stand-alone or capture-board-integrated operation with EVAL-CED1Z or EVAL-CONTRL BRDxZ.

For engineers reviewing the EVAL-AD7621CBZ datasheet, EVAL-AD7621CBZ pinout, EVAL-AD7621CBZ application, or EVAL-AD7621CBZ equivalent, this board enables rapid characterization of DC accuracy (histogram), AC performance (SNR, SINAD, THD, SFDR via FFT), decimated oversampling up to 32-bit resolution, and configurable input ranges (0–2.5V differential unipolar) for high-fidelity data acquisition system prototyping.

Technical Context

The EVAL-AD7621CBZ implements a 4-layer PCB layout with separated analog and digital ground planes joined directly under the ADC to preserve 16-bit resolution. It uses a gate array (U10) to generate CNVST, manage BUSY signaling, and buffer conversion data - supporting both internal (40MHz oscillator U12) and external CNVST sources via SMB connector J3.

Analog input conditioning includes dual op-amps (U6, U7) configured as unity-gain buffers by default, with selectable ±12V supplies (via SJ1/SJ2) and jumper-configurable reference routing (JP4), buffer enable (JP1/JP2), and output supply (JP6). The board delivers BD[0:15] on a 40-pin IDC connector (P2) and routes serial signals (SDOUT, SCLK, SYNC) to test points TP17–TP19.

Key Specifications

Availability

EVAL-AD7621CBZ is available at Aetrix Electronics and suitable for high-precision data acquisition, industrial sensor interface, medical instrumentation, and test & measurement applications requiring stable component supply and full-spectrum ADC validation capability.

Supply support for EVAL-AD7621CBZ 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 semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control systems.

The EVAL-AD7621CBZ belongs to Analog Devices' PulSAR® ADC evaluation platform family, engineered to accelerate development of high-speed, high-resolution data acquisition systems using SAR architecture converters.

FAQ

What is the primary function of the EVAL-AD7621CBZ?

The EVAL-AD7621CBZ is an evaluation board specifically designed to characterize and validate the AD7621 16-bit, 3MSPS SAR ADC. It provides complete hardware infrastructure-including reference, clock, analog conditioning, parallel/serial I/O, and PC software-for measuring DC accuracy (transition noise), AC performance (SNR, SINAD, THD), and oversampled resolution. The EVAL-AD7621CBZ does not operate as a standalone data acquisition device but serves exclusively as a development and verification tool for the AD7621 IC.

Which ADC models does the EVAL-AD7621CBZ support besides the AD7621?

The EVAL-AD7621CBZ is part of the EVAL-AD76XXCBZ family and supports multiple 48-lead PulSAR® ADCs including AD7622, AD7623, AD7625, AD7641, AD7643, and selected AD761x/AD763x/AD765x/AD766x/AD767x/AD795x variants. However, its default configuration-jumper settings (JP19, JP6), power rails (+2.5V AVDD), and analog input scaling-is optimized for the AD7621's 0–2.5V differential unipolar input range and 3MSPS throughput. Other devices require manual reconfiguration per their datasheet requirements.

Does the EVAL-AD7621CBZ include on-board clock and reference circuitry?

Yes, the EVAL-AD7621CBZ integrates a 40MHz local oscillator (U12) for master clock generation and supports three precision voltage references: AD780, ADR431, or ADR435. Reference routing is controlled by jumper JP4 (REF/VDD), and buffering is enabled/disabled via JP20 (BUFF/NO BUFF). These components ensure low-jitter CNVST timing and stable reference voltage-critical for achieving the AD7621's specified 92.5dB SNR and ±1.5 LSB INL-without requiring external support circuitry.

Can the EVAL-AD7621CBZ operate without a host capture board like EVAL-CED1Z or EVAL-CONTRL BRDxZ?

Yes, the EVAL-AD7621CBZ supports stand-alone operation. When the CONTROL input to the gate array (U10) is held LOW (default via pull-down), U10 autonomously generates CNVST, manages BUSY signaling, and buffers conversion data onto BD[0:15]. In this mode, parallel output is continuously updated on the 40-pin IDC connector P2 after BUSY goes HIGH, and configuration is managed via DIP switches S16/S35-not software. No PC connection or capture board is required for basic conversion and output monitoring.

What software tools are provided for the EVAL-AD7621CBZ?

Analog Devices provides two dedicated Windows-based software packages: "AD76xx Evaluation Software CED" (for use with EVAL-CED1Z) and "AD76xx Evaluation Software ECB" (for EVAL-CONTROL-BRDXZ). Both support histogram analysis (DC code distribution), FFT-based AC testing (SNR, SINAD, THD, SFDR), and decimated oversampling. The CED version supports EVAL-AD7621CBZ directly; the ECB version requires EVAL-CONTROL-BRD3 for decimation. Software installs USB or parallel-port drivers and provides real-time visualization of raw and processed ADC data.