Analog Devices Inc. EVAL-AD7991EBZ

Overview

EVAL-AD7991EBZ from Analog Devices is a fully featured USB-powered evaluation board for the AD7991 4-channel, 12-bit I²C-compatible analog-to-digital converter. It supports single-supply operation (2.7 V to 5.5 V), delivers 1 μs conversion time, and includes on-board AD8691 op amps, AD5245 digital potentiometers, and AD780 precision reference for configurable analog signal conditioning and ADC testing.

For engineers reviewing the EVAL-AD7991EBZ datasheet, EVAL-AD7991EBZ pinout, EVAL-AD7991EBZ application, or EVAL-AD7991EBZ equivalent, this board enables rapid functional validation of the AD7991 in sensor interface, industrial monitoring, and data acquisition systems - with USB control, real-time waveform visualization, and flexible input routing via SMB connectors and jumper links.

Technical Context

The EVAL-AD7991EBZ implements a complete test environment for the AD7991 ADC, integrating Cypress USB microcontroller (U2) for host communication, ADP3303AR-3.3 and ADP3330ARTZ-3.6-R7 regulators for clean 3.3 V and 3.6 V supplies, and AD780ARZ reference (2.5 V/3.0 V selectable) for stable conversion accuracy. All four analog inputs (AN0–AN3) are accessible via SMB connectors and configurable through 14 jumpers (LK1–LK14).

Signal path flexibility is achieved via dual AD5245 digital potentiometers (U6/U9) and five AD8691 op amps (U7/U10/U12/U14/X3), enabling gain/offset adjustment, buffer isolation, and multiplexer input conditioning. The board operates exclusively from USB 5 V (J1), eliminating need for external power.

Key Specifications

Availability

EVAL-AD7991EBZ is available at Aetrix Electronics and suitable for sensor interface validation, industrial process monitoring, and embedded data acquisition system development requiring stable component supply and rapid prototyping support.

Supply support for EVAL-AD7991EBZ 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.

The EVAL-AD7991EBZ belongs to Analog Devices' precision data converter evaluation platform family, designed specifically to accelerate characterization and integration of low-power, multi-channel SAR ADCs into measurement and control applications.

FAQ

What is the primary function of the EVAL-AD7991EBZ?

The EVAL-AD7991EBZ is a dedicated evaluation board for the AD7991 4-channel, 12-bit I²C-compatible ADC. It provides full hardware and software infrastructure-including USB interface, configurable analog front-end, precision reference, and PC GUI-to validate ADC performance, test signal chain configurations, and develop firmware without custom PCB design. EVAL-AD7991EBZ enables immediate functional assessment of the AD7991 in real-world conditions.

Does the EVAL-AD7991EBZ support both AD7991 and AD7995 devices?

Yes, the EVAL-AD7991EBZ is compatible with both the AD7991 (12-bit) and AD7995 (10-bit) devices, as confirmed by its official designation "EVAL-AD7991/AD7995" and shared schematic implementation. Both ICs share identical pinout, I²C protocol, power requirements, and analog input structure-allowing the same board to evaluate either device with no hardware modification. EVAL-AD7991EBZ ships with firmware and software supporting both variants.

How is analog input configured on the EVAL-AD7991EBZ?

Analog inputs on the EVAL-AD7991EBZ are routed via 14 configurable jumpers (LK1–LK14) and four SMB connectors (AN0–AN3). Each channel can be connected directly to an SMB socket or conditioned through one of two AD5245 digital potentiometers and/or an AD8691 op amp buffer. LK3–LK6/LK8 select op-amp usage per channel; LK1/LK2/LK5/LK10 route VINx to pot or socket; LK7 selects ADC supply voltage. This enables precise signal conditioning and topology testing.

What reference voltage options does the EVAL-AD7991EBZ provide?

The EVAL-AD7991EBZ uses the AD780ARZ ultraprecision bandgap reference, supporting 2.5 V or 3.0 V output selected by inserting or removing LK9. This reference feeds the AD7991's VREF pin and is independent of the ADC's DVDD supply. The board also allows using DVDD (3.3 V or 5 V) as reference via software selection (Ref-VDD control), but AD780 provides highest accuracy for calibration-critical applications. EVAL-AD7991EBZ documentation confirms both modes are validated.

Is external power required to operate the EVAL-AD7991EBZ?

No external power is required. The EVAL-AD7991EBZ draws all operating power from the USB 5 V supply via connector J1. On-board ADP3303AR-3.3 and ADP3330ARTZ-3.6-R7 regulators generate clean 3.3 V and 3.6 V rails for the AD7991, op amps, and digital potentiometers. Power selection for the ADC (3.3 V vs. 5 V) is controlled solely by jumper LK7-no additional power sources, adapters, or bench supplies are needed for standard operation. EVAL-AD7991EBZ is fully self-contained.