Analog Devices Inc. EVAL-AD977ACB

Overview

EVAL-AD977ACB from Analog Devices is an evaluation board for the AD977A 16-bit, 200 kSPS successive approximation ADC, designed to demonstrate high-accuracy data acquisition in single 5 V supply systems. It supports ±10 V, ±5 V, and 0 V–5 V input ranges, features on-chip 2.5 V reference, high-speed serial interface, and operates in SOIC-20 or SSOP-28 packages.

For engineers reviewing the EVAL-AD977ACB datasheet, EVAL-AD977ACB pinout, EVAL-AD977ACB application, or EVAL-AD977ACB equivalent, key selection considerations include ADC resolution (16-bit), throughput (200 kSPS), unipolar/bipolar range flexibility, internal/external reference support, and serial data timing modes (internal vs. external DATACLK).

Technical Context

The EVAL-AD977ACB enables full characterization of the AD977A's factory-calibrated switched-capacitor SAR architecture, including dc accuracy (±0.3% full-scale error, ±10 mV bipolar zero error) and ac performance (85 dB SNR, 96 dB SFDR at 20 kHz). It supports both internal clock mode (16-pulse DATACLK burst) and external clock mode with SYNC framing for multi-device daisy-chaining via TAG.

Board-level implementation validates critical timing parameters: aperture delay (40 ns), acquisition time (1 µs), BUSY low duration (4–8 µs), and conversion + read latency under discontinuous clock (≤17 DATACLK edges for full 16-bit read). Power-down mode (50 µW) and dual ground isolation (AGND1/AGND2/DGND) are also verified.

Key Specifications

Availability

EVAL-AD977ACB is available at Aetrix Electronics and suitable for industrial process control, automated test equipment, and precision sensor signal conditioning requiring stable component supply and rapid prototyping validation.

Supply support for EVAL-AD977ACB 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-AD977ACB belongs to Analog Devices' precision data acquisition evaluation platform family, engineered to accelerate design-in of high-resolution ADCs in applications demanding low noise, tight linearity, and robust timing integrity.

FAQ

What is the primary function of the EVAL-AD977ACB evaluation board?

The EVAL-AD977ACB evaluation board is a fully assembled and tested platform for evaluating the AD977A 16-bit, 200 kSPS SAR ADC. It provides access to all critical signals-including R/C, CS, DATACLK, DATA, SYNC, and REF-to validate conversion accuracy, timing behavior, reference stability, and interface compatibility in real system conditions. The EVAL-AD977ACB does not contain the AD977A IC itself but is configured to host it in either SOIC-20 or SSOP-28 package variants.

Does the EVAL-AD977ACB support both AD977 and AD977A devices?

No - the EVAL-AD977ACB is specifically designed for the AD977A (200 kSPS version). While pin-compatible with the AD977 (100 kSPS), its layout, timing calibration, and documentation focus on AD977A specifications, including 1 µs transient response, 1 MHz full-power bandwidth, and 1.2 mA external reference current draw. Using the AD977 on EVAL-AD977ACB is possible but not characterized or supported by Analog Devices' official test data.

How is the reference voltage configured on the EVAL-AD977ACB?

The EVAL-AD977ACB supports both internal and external reference operation. The AD977A's internal 2.5 V reference is enabled by leaving the REF pin unconnected and populating the on-board 2.2 µF tantalum capacitor between CAP and AGND2. For external reference use, a precision 2.3–2.7 V source is applied to REF, and the same 2.2 µF capacitor is retained. Jumper options on the EVAL-AD977ACB allow hardware selection between these modes without soldering changes.

Can the EVAL-AD977ACB demonstrate daisy-chained operation of multiple AD977A converters?

Yes - the EVAL-AD977ACB includes provisions to verify TAG-based daisy-chaining as specified in the AD977A datasheet. When EXT/INT = HIGH and multiple EVAL-AD977ACB boards (each hosting an AD977A) share a common DATACLK and SYNC, the TAG input of one board can be driven by the DATA output of another. This allows sequential 16-bit reads from up to two devices on a single DATA line, with timing delays of 16–17 DATACLK periods confirmed per device on the EVAL-AD977ACB.

What power supply requirements must be met to operate the EVAL-AD977ACB correctly?

The EVAL-AD977ACB requires a clean, well-decoupled 5 V ±5% supply delivering ≥15 mA total (11 mA analog, 4 mA digital). Separate VANA and VDIG inputs are provided with dedicated 0.1 µF ceramic + 10 µF tantalum decoupling per rail. Grounding follows strict partitioning: AGND1 (REF reference), AGND2 (CAP filter), and DGND are tied at a single point near the power entry connector. Failure to maintain <0.3 V ground potential difference between AGND and DGND risks degraded INL and increased noise on the EVAL-AD977ACB.