Analog Devices Inc. EVAL-AD7655CBZ

Overview

EVAL-AD7655CBZ from Analog Devices is an evaluation board designed for the AD7655 - a 16-bit, 4-channel, single-ended, unipolar SAR ADC with 500 kSPS throughput and 0 V to 5 V analog input range. It provides buffered parallel (16-bit) and serial interfaces, on-board precision reference (AD780/ADR431/ADR435), clock oscillator, signal conditioning op-amps, and analog/digital prototyping area. It supports stand-alone operation or integration with EVAL-CED1Z or EVAL-CONTRL BRDxZ capture boards for data acquisition system validation.

For engineers reviewing the EVAL-AD7655CBZ datasheet, EVAL-AD7655CBZ pinout, EVAL-AD7655CBZ application, or EVAL-AD7655CBZ equivalent, this page delivers verified technical context, interface configuration options, power supply routing guidance, software-supported test modes (histogram, FFT, decimation), and hardware setup requirements for high-resolution ADC evaluation in industrial and instrumentation designs.

Technical Context

The EVAL-AD7655CBZ implements a flexible gate array (U10) that generates CNVST, manages BUSY signaling, buffers ADC output data (BD[0:15]), and supports both parallel and serial read modes. It accommodates the AD7655's 4-channel SE unipolar architecture via configurable analog front-end op-amps (U6/U7), selectable ±12 V / +5 V supplies, and jumper-controlled reference routing (JP4), buffer enable (JP1/JP2), and digital I/O voltage (JP21).

Hardware configuration is managed through dual DIP switches (S16/S35) enabling mode selection (Warp/Normal/Impulse), binary vs. 2's complement output, byte-swapping, and serial clock source (internal or external). The board uses a 4-layer PCB layout with separated analog/digital ground planes tied under the ADC to preserve SNR performance during dynamic testing.

Key Specifications

Availability

EVAL-AD7655CBZ is available at Aetrix Electronics and suitable for high-precision data acquisition, industrial process monitoring, and test & measurement equipment requiring stable component supply, traceable sourcing, and long-term evaluation platform continuity.

Supply support for EVAL-AD7655CBZ 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 Norwood, MA, with design and manufacturing expertise spanning precision converters, amplifiers, RF, and power management.

The EVAL-AD7655CBZ belongs to Analog Devices' PulSAR® evaluation platform family, engineered specifically to accelerate development of high-resolution SAR ADC systems for instrumentation, energy metering, and automated test equipment where DC accuracy and AC fidelity are critical.

FAQ

What is the primary function of the EVAL-AD7655CBZ?

The EVAL-AD7655CBZ is an evaluation board purpose-built to characterize and validate the AD7655 - a 16-bit, 4-channel, single-ended, unipolar SAR ADC operating up to 500 kSPS. It provides full hardware and software infrastructure for DC and AC performance testing, including histogram, FFT, and decimation analysis, and supports both stand-alone use and integration with EVAL-CED1Z or EVAL-CONTRL BRDxZ capture boards. The EVAL-AD7655CBZ enables rapid prototyping of data acquisition systems before final PCB design.

Which ADC models does the EVAL-AD7655CBZ support besides the AD7655?

The EVAL-AD7655CBZ is part of the broader EVAL-AD76XXCBZ platform supporting multiple 48-lead PulSAR® ADCs, including AD761x, AD762x, AD763x, AD764x, AD766x, AD767x, and AD795x families. Specific compatibility with the AD7655 is confirmed by its inclusion in Table 1 of the preliminary technical data, which lists AD7655 with 16-bit resolution, 500 kSPS, 0 V to 5 V input, and 4-channel single-ended configuration. The board's jumper and switch settings (e.g., S16-A0/M0 for AD7654/AD7655) are explicitly tailored for the AD7655's channel multiplexing behavior.

How does the EVAL-AD7655CBZ handle analog input configuration for the AD7655?

The EVAL-AD7655CBZ configures the AD7655's analog input using a dual-op-amp signal conditioning stage (U6/U7) with jumper-selectable gain, supply rails (JP3, JP8), and buffering (JP1/JP2). For the AD7655's 0 V to 5 V unipolar input, the board is factory-set with unity-gain buffers and ±12 V supplies. Input range scaling or bipolar adaptation requires discrete modifications per AN594 or device-specific datasheet guidance - not automatic reconfiguration. The EVAL-AD7655CBZ does not auto-detect ADC type; users must manually set S16/S35 switches and jumpers to match AD7655 timing, coding, and interface requirements.

Can the EVAL-AD7655CBZ operate without a host PC or capture board?

Yes, the EVAL-AD7655CBZ supports true stand-alone operation. When the CONTROL input to the gate array (U10) is held LOW (default via pull-down), it autonomously generates CNVST, manages BUSY signaling, and buffers conversion data onto BD[0:15] at P2. In parallel mode, CS and RD are driven LOW, enabling continuous data streaming without tri-state control. The AD7655's full 16-bit output appears directly on the 40-pin IDC connector, and test points (e.g., TP1 for BUSY, T3–T6 for serial signals) allow oscilloscope-based verification independent of PC software or capture hardware.

What software tools are provided for the EVAL-AD7655CBZ, and what tests do they perform?

Analog Devices provides two dedicated software packages: AD76xx Evaluation Software CED (for EVAL-CED1Z) and AD76xx Evaluation Software ECB (for EVAL-CONTRL BRDxZ). Both support histogram (transition noise, code distribution), FFT (SNR, SINAD, THD, SFDR), and decimated AC analysis. The software acquires raw ADC data, performs real-time computation, and displays time-domain waveforms, spectral plots, and statistical summaries. For the EVAL-AD7655CBZ, these tools validate the AD7655's 16-bit linearity and dynamic performance under actual system conditions - not just datasheet conditions - using calibrated on-board references and low-jitter clock sources.