Analog Devices Inc. EVAL-AD7685CBZ

Overview

EVAL-AD7685CBZ from Analog Devices is an evaluation board designed specifically for the AD7685CRMZ - a 16-bit, 250 kSPS PulSAR® successive-approximation ADC in a 10-lead MSOP package. It provides buffered parallel output, on-board 5 V ultrahigh-precision reference (ADR435), dual op-amp signal conditioning (ADA4841-x), and configurable analog front-end for unipolar/differential input modes. It supports lab-based performance validation of high-accuracy data acquisition systems.

For engineers reviewing the EVAL-AD7685CBZ datasheet, EVAL-AD7685CBZ pinout, EVAL-AD7685CBZ application, or EVAL-AD7685CBZ equivalent, this page delivers verified hardware configuration details, jumper-controlled signal path options (JP1–JP11), test point access (TP1–TP13), software-supported FFT/histogram analysis, and compatibility with EVAL-CONTROL BRD2/BRD3 controller boards for full-system characterization.

Technical Context

The EVAL-AD7685CBZ implements a four-layer PCB layout optimized for low-noise, high-accuracy ADC evaluation. It integrates dual ADA4841-x op-amps for gain/offset/flexibility in analog front-end conditioning and uses ADR435 as the primary 5 V reference source - selectable via JP4 and buffered optionally via AD8032 (JP5). The board supports both standalone serial interface operation (via 26-pin IDC P1) and synchronized parallel-mode evaluation (BD0–BD15, BBUSY) when paired with EVAL-CONTROL BRDx.

Configurable jumpers enable real-time adaptation to target ADC variants: JP3 selects unipolar (AD7683/AD7685/AD7694) or differential (AD7684/AD7687/AD7688) input mode; JP12 sets pin compatibility for AD7685CRMZ (position A); and JP1/J2 route signals through amplifiers (AMP+) or optional ADG739 multiplexer outputs (DB/DA). Power domains are isolated via SJ1 (digital) and SJ2 (analog), supporting independent supply testing.

Key Specifications

Availability

EVAL-AD7685CBZ is available at Aetrix Electronics and suitable for precision data acquisition, industrial sensor interface, and embedded instrumentation applications requiring stable component supply, traceable sourcing, and long-term evaluation platform continuity.

Supply support for EVAL-AD7685CBZ 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.

The EVAL-AD7685CBZ belongs to Analog Devices' PulSAR® ADC evaluation platform family, engineered to accelerate validation of high-resolution, low-power SAR converters in demanding measurement and instrumentation applications.

FAQ

What is the primary ADC supported by EVAL-AD7685CBZ?

EVAL-AD7685CBZ is factory-configured and validated for the AD7685CRMZ - a 16-bit, 250 kSPS PulSAR® ADC in a 10-lead MSOP package. Its jumper settings (especially JP3 set to "SGL" and JP12 in position A) match the AD7685CRMZ's unipolar input architecture and pinout. While compatible with other AD768x/AD769x devices, EVAL-AD7685CBZ's default calibration and documentation focus on AD7685CRMZ performance verification.

Does EVAL-AD7685CBZ require EVAL-CONTROL BRD2 or BRD3 to operate?

EVAL-AD7685CBZ supports two operational modes: When used with EVAL-CONTROL BRD2 or BRD3, it enables full PC-based software control (histogram, FFT, decimated averaging) via the 96-way connector P3. In standalone mode, EVAL-AD7685CBZ operates independently using its 26-pin IDC serial interface (P1), allowing direct microcontroller or FPGA integration without external controller hardware - though software analysis features are unavailable.

How is analog input configured for AD7685CRMZ on EVAL-AD7685CBZ?

For AD7685CRMZ evaluation, analog input is configured via JP3 (set to "SGL" for unipolar mode), JP1 (AMP+ position to route signal through U6 amplifier), and JP2 (AMP− position to route signal through U7 amplifier). Input signals connect via SMB connectors J1 (AIN+) and J2 (AIN−), with test points TP3 (SIG+) and TP13 (SIG−) providing direct access. Factory gain is unity, and mid-scale DC offset enables transition noise testing without external equipment.

What reference voltage options does EVAL-AD7685CBZ provide for AD7685CRMZ?

EVAL-AD7685CBZ offers two reference configurations for AD7685CRMZ: JP4 set to "ADR43X" selects the onboard 5 V ADR435 reference (low-drift, high-precision), while "VDD" routes the ADC's VDD supply as reference. JP5 further allows buffering of either source using AD8032 - critical when VDD exhibits noise or instability, as the buffer improves PSRR and reduces reference coupling into the conversion path.

Can EVAL-AD7685CBZ evaluate multiple ADCs simultaneously?

Yes - EVAL-AD7685CBZ includes provision for a second ADC (U8 location) to demonstrate daisy-chain operation, enabling synchronized sampling across two AD7685CRMZ (or compatible) devices. This requires manual population of U8 and configuration of JP12 for matching device type. The board's shared clock (MCLK), CNV, and SDO2 signals support timing-coherent multi-ADC evaluation without external synchronization circuitry.