Analog Devices Inc. EVAL-AD7706EBZ

Overview

EVAL-AD7706EBZ from Analog Devices is a full-featured evaluation board designed to interface with and characterize the AD7706 3V/5V, 450 µA, 3-channel, 16-bit sigma-delta ADC. It includes on-board AD780 (2.5 V) and AD589 (1.23 V) precision references, a 4.9152 MHz crystal oscillator, digital buffers, and user-configurable link options for clock, reference, and analog input routing - enabling rapid prototyping of low-frequency sensor measurement systems.

For engineers reviewing the EVAL-AD7706EBZ datasheet, EVAL-AD7706EBZ pinout, EVAL-AD7706EBZ application, or EVAL-AD7706EBZ equivalent, this board supports direct PC connection via parallel port (SKT2), flexible analog signal conditioning via SMB sockets (SKT3–SKT6), on-board patchwork area, and Windows-based software for register-level control, real-time data acquisition, noise analysis, and calibration verification.

Technical Context

The EVAL-AD7706EBZ implements a complete hardware test environment for the AD7706 ADC, featuring dual reference selection (2.5 V AD780 or 1.23 V AD589), configurable master clock source (on-board 4.9152 MHz crystal or external via SKT11), and eight jumper links (LK1–LK8) that route analog inputs (AIN1±, AIN2±, AIN3), reference inputs (REFIN±), and digital signals without soldering. All critical power rails - AVDD/AGND and DVDD/DGND - are independently decoupled using 10 µF tantalum + 0.1 µF ceramic capacitors.

Digital interfacing is supported through two connectors: a 9-way D-type (SKT1) for custom system integration and a 36-way Centronics (SKT2) for standard PC parallel port communication. Buffered serial signals (SCLK, DIN, DOUT, DRDY, CS, RESET) isolate the AD7706 from host noise, while SW1 provides hardware reset functionality aligned with the AD7706's active-low RESET requirement.

Key Specifications

Availability

EVAL-AD7706EBZ is available at Aetrix Electronics and suitable for industrial sensor interface development, precision instrumentation prototyping, and embedded analog front-end validation requiring stable component supply, traceable sourcing, and long-term evaluation platform continuity.

Supply support for EVAL-AD7706EBZ 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 (DSP) technologies, headquartered in Wilmington, MA, serving industrial, automotive, communications, and healthcare markets.

The EVAL-AD7706EBZ belongs to Analog Devices' precision data acquisition evaluation platform family, engineered specifically to accelerate design-in of sigma-delta ADCs in low-noise, low-drift, high-resolution measurement applications such as weigh scales, temperature monitoring, and bridge sensor interfaces.

FAQ

What is the primary function of the EVAL-AD7706EBZ?

The EVAL-AD7706EBZ is an evaluation board dedicated to the AD7706 3-channel, 16-bit sigma-delta ADC. It enables engineers to configure, program, acquire data from, and validate the performance of the AD7706 under real-world conditions - including reference selection, clock sourcing, analog input routing, and digital interface testing - all without custom PCB design. The EVAL-AD7706EBZ provides immediate access to all registers and analog paths defined in the AD7706 datasheet.

Does the EVAL-AD7706EBZ support both AD7705 and AD7706 devices?

Yes, the EVAL-AD7706EBZ is shared with the AD7705 and explicitly supports both devices - the board accommodates the AD7705 (2-channel) and AD7706 (3-channel) in identical footprint and pinout configurations. Jumpers LK5–LK8 allow full access to all three differential input pairs (AIN1±, AIN2±, AIN3±) when used with the AD7706, while maintaining backward compatibility with the AD7705's two-channel mode.

How is the EVAL-AD7706EBZ powered, and what are the voltage requirements?

The EVAL-AD7706EBZ requires separate analog and digital supplies: AVDD/AGND must be supplied at either +3 V or +5 V via terminal block J2, and DVDD/DGND may be supplied via J1, SKT1 pin 8, or SKT2 pin 9. The board implements strict analog/digital ground separation - AGND and DGND are joined only at the AD7706 GND pin - and mandates independent decoupling (10 µF tantalum + 0.1 µF ceramic) on each supply rail to preserve ADC accuracy.

Can the EVAL-AD7706EBZ operate without a PC connection?

No - the EVAL-AD7706EBZ is not a standalone measurement tool. It requires a host PC running the included Windows-based software to drive the AD7706 via SKT2 (parallel port) or SKT1 (custom interface). All register writes, data reads, calibration sequences, and noise analysis depend on the software stack; no onboard microcontroller or autonomous firmware is present on the EVAL-AD7706EBZ.

What reference voltages are available on the EVAL-AD7706EBZ, and how are they selected?

The EVAL-AD7706EBZ provides two precision references: AD780 (2.5 V) for +5 V AD7706 operation and AD589 (1.23 V) for +3 V operation. Selection is made via jumper LK2: position "A" routes AD780 to REFIN(+), and position "B" routes AD589. Additional flexibility is provided by LK3 and LK4, which allow external reference sources to be connected via SKT9 (REFIN+) and SKT10 (REFIN−), enabling custom reference configurations beyond the on-board options.