Analog Devices Inc. EVAL-AD976CB

Overview

EVAL-AD976CB from Analog Devices is an evaluation board designed to demonstrate and validate the AD976/AD976A 16-bit, 100 kSPS/200 kSPS BiCMOS analog-to-digital converter. It provides full access to the ADC's parallel interface, internal 2.5 V reference, on-chip clock, ±10 V analog input range, and dual ground architecture (AGND1/AGND2/DGND) for precision signal acquisition in industrial data acquisition and test instrumentation systems.

For engineers reviewing the EVAL-AD976CB datasheet, EVAL-AD976CB pinout, EVAL-AD976CB application, or EVAL-AD976CB equivalent, this board enables rapid functional verification of the AD976/AD976A's DC accuracy (±3 LSB INL), AC performance (83 dB S/(N+D)), timing behavior (4–8 µs conversion time), and reference flexibility (internal or external 2.5 V) under real-world layout and supply conditions.

Technical Context

The EVAL-AD976CB implements a complete signal chain for the AD976/AD976A, including buffered ±10 V analog input conditioning with 200 Ω series resistor and 2.2 µF tantalum decoupling at REF/CAP pins, dedicated analog/digital power planes, and direct connection to a 16-bit parallel bus with BYTE and R/C control logic routing. It supports both AD976 (100 kSPS) and AD976A (200 kSPS) variants via jumper-selectable configuration.

Board-level design enforces strict separation between AGND1 (reference ground), AGND2 (capacitor buffer ground), and DGND (digital ground), with star-point grounding at the ADC's ground pins. The PCB layout follows Analog Devices' recommended practices for high-resolution ADC evaluation, including minimized trace lengths for VIN, REF, CAP, and BUSY signals, and controlled-impedance routing for D0–D15 data lines.

Key Specifications

Availability

EVAL-AD976CB is available at Aetrix Electronics and suitable for industrial data acquisition, automated test equipment, and precision instrumentation requiring stable component supply, full-signal-chain validation, and factory-calibrated ADC performance verification.

Supply support for EVAL-AD976CB 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 Wilmington, MA.

The EVAL-AD976CB belongs to Analog Devices' precision data conversion evaluation platform family, engineered to accelerate prototyping and characterization of high-resolution ADCs in demanding measurement applications.

FAQ

What is the primary function of the EVAL-AD976CB evaluation board?

The EVAL-AD976CB evaluation board is specifically designed to evaluate the AD976 and AD976A 16-bit analog-to-digital converters. It provides a fully laid-out, tested platform with proper grounding, decoupling, and signal routing to validate key parameters-including integral nonlinearity (±3 LSB), signal-to-noise-plus-distortion (83 dB), and conversion timing-under real operating conditions. The board enables immediate functional testing without custom PCB development.

Which ADC variants does the EVAL-AD976CB support?

The EVAL-AD976CB supports both the AD976 (100 kSPS throughput) and AD976A (200 kSPS throughput) families. Jumper settings allow users to configure the board for either variant, ensuring correct timing margins, power sequencing, and reference biasing per device specification. Pin compatibility across all 28-lead package options (DIP, SOIC, SSOP) is maintained.

Does the EVAL-AD976CB include an on-board power supply?

No, the EVAL-AD976CB does not include an on-board power supply. It requires two clean, regulated +5 V supplies: one for VANA (analog) and one for VDIG (digital), each capable of delivering ≥15 mA. Separate ground returns (AGND1, AGND2, DGND) must be connected at the board's designated star point to preserve ADC accuracy and minimize noise coupling.

How is analog input protection implemented on the EVAL-AD976CB?

The EVAL-AD976CB implements ±25 V absolute maximum input protection on VIN using the AD976/AD976A's internal clamping structure. External circuitry includes a 200 Ω series resistor (per datasheet recommendation) to limit current and stabilize sampling dynamics, along with proper 2.2 µF tantalum capacitor placement at REF and CAP pins referenced to AGND1 and AGND2 respectively.

Can the EVAL-AD976CB be used with an external reference voltage?

Yes, the EVAL-AD976CB supports external reference operation. The REF pin is accessible via test point and header, allowing connection of a stable 2.3–2.7 V external reference. When used, the internal 2.5 V reference is disabled, and the board maintains full specification compliance-including full-scale error drift (±0.5 %) and linearity-provided the external source meets current drain (≤100 µA) and noise requirements outlined in the AD976/AD976A datasheet.