Analog Devices Inc. AD9251-20EBZ

Overview

AD9251-20EBZ from Analog Devices is a full-featured evaluation board designed to characterize the AD9251 12-bit, 20 MSPS analog-to-digital converter in multiple configurations. It supports SPI-based setup, dual-channel CMOS output capture, transformer-coupled clock input, and flexible analog input drive via balun or optional amplifier paths. The board enables high-fidelity AC performance evaluation up to ~150 MHz input frequency with 2 V p-p full-scale range.

For engineers reviewing the AD9251-20EBZ datasheet, AD9251-20EBZ pinout, AD9251-20EBZ application, or AD9251-20EBZ equivalent, key selection considerations include its support for internal/external reference modes, LDO vs. ADP2114 switching power supply options, default transformer-coupled clock path with Valpey Fisher oscillator (50/65/80 MHz), and compatibility with HSC-ADC-EVALCZ FPGA data capture platform.

Technical Context

The AD9251-20EBZ implements a dedicated hardware interface for the AD9251 ADC, featuring dual independent analog input channels (A/B) with configurable 50 Ω terminated, double-balun-coupled front ends optimized for up to ~150 MHz analog input frequencies. It integrates on-board clock conditioning using a high-bandwidth 1:1 transformer (T601) and supports both internal (1.0 V) and external reference sources.

SPI communication is routed directly to the AD9251's control pins (CS, SCLK/DFS, SDIO/DCS) via jumpers J302, enabling register configuration for data format (offset binary/twos complement), DCS enable, and power-down/OE control. Power delivery includes default LDO regulation (6 V input → 1.8 V AVDD/DRVDD/DVDD) and an optional ADP2114 buck converter configuration for improved efficiency.

Key Specifications

Availability

AD9251-20EBZ is available at Aetrix Electronics and suitable for high-speed data acquisition, communications test equipment, and instrumentation applications requiring stable component supply, traceable sourcing, and long-term evaluation platform continuity.

Supply support for AD9251-20EBZ 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 high-speed conversion.

The AD9251-20EBZ belongs to Analog Devices' high-speed ADC evaluation platform family, engineered specifically to accelerate characterization and system integration of pipeline ADCs in demanding RF, instrumentation, and communications applications.

FAQ

What is the primary function of the AD9251-20EBZ?

The AD9251-20EBZ is an evaluation board-not a semiconductor component-that provides all necessary support circuitry to operate the AD9251 12-bit, 20 MSPS dual-channel analog-to-digital converter. It enables engineers to validate AC performance (SNR, SFDR), configure SPI registers, test clocking options (on-board oscillator or external source), and integrate the AD9251 into system-level designs using VisualAnalog and SPI Controller software tools.

Does the AD9251-20EBZ include the AD9251 IC?

Yes, the AD9251-20EBZ evaluation board is populated with the AD9251 ADC as the device under test (DUT). The board is pre-configured with default jumpers (e.g., J302 for SPI, J605 for oscillator enable) and calibrated passive components to match the AD9251's electrical specifications, including 2 V p-p full-scale input range and 1.0 V internal reference voltage.

Which clock sources are supported by the AD9251-20EBZ?

The AD9251-20EBZ supports three clock configurations: (1) on-board Valpey Fisher VFAC3-BHL oscillator (50/65/80 MHz, enabled via J605), (2) external single-ended sine wave (2.8 V p-p or 13 dBm) via SMA connector J602, and (3) differential LVPECL output from AD9517 clock generator (U701), activated by populating R607/R608/R731/R732 and removing R609/R610/R611/R612.

Can the AD9251-20EBZ be powered using bench supplies instead of the included wall adapter?

Yes, the AD9251-20EBZ can be powered via external bench supplies. To do so, remove ferrite beads E101, E102, E114, E103, E105, and E107 to isolate on-board LDOs, then apply 1.8 V (1 A) to P102 for DUT_AVDD/DRVDD and 1.8 V (1 A) to P103 for DVDD. A separate 3.3 V (1 A) supply is required for 3V_CLK if using SPI or alternate clock modes.

Is the AD9251-20EBZ compatible with other ADC families listed in UG-003?

No-the AD9251-20EBZ is specifically configured for the AD9251 and shares hardware compatibility only with other members of the AD9269 family (AD9231, AD9204, AD9269, AD6659) per Table 1 in UG-003. While the board's physical layout accommodates multiple families, jumper settings, input networks (Figure 5), reference voltages (1.0 V), and clock circuitry are fixed for AD9251 operation and must not be assumed interoperable with AD9268 or AD9650 variants.