Analog Devices Inc. EVAL-AD7091SDZ

Overview

EVAL-AD7091SDZ from Analog Devices is an evaluation board for the AD7091, a 12-bit successive approximation register (SAR) analog-to-digital converter. It supports full characterization of the AD7091's ultralow power operation (367 µA at 3 V/1 MSPS), ±1 LSB INL, 0 V to VDD input range, and SPI/QSPI/MICROWIRE-compatible serial interface in an 8-lead 2 mm × 2 mm LFCSP package.

For engineers reviewing the EVAL-AD7091SDZ datasheet, EVAL-AD7091SDZ pinout, EVAL-AD7091SDZ application, or EVAL-AD7091SDZ equivalent, this board enables rapid validation of the AD7091's performance in battery-powered instrumentation, handheld meters, and energy-harvesting sensor nodes under real-world signal chain conditions including source impedance, decoupling, and timing margins.

Technical Context

The EVAL-AD7091SDZ implements a direct, unmodified interface to the AD7091 IC, preserving its native 12-bit SAR architecture, internal VDD-derived reference, on-chip track-and-hold, and conversion control via CONVST edge triggering. It provides access to all eight pins-including REGCAP for LDO bypass and SDO with optional busy-indicator pull-up-enabling accurate measurement of dynamic parameters like SNR (69.84 dB), THD (−81.05 dB), and aperture jitter (40 ps).

Board-level design strictly follows Analog Devices' recommended layout: dual decoupling (10 µF + 0.1 µF on VDD), 1 µF on REGCAP, 51 Ω series resistor + 4.7 nF RC filter on VIN, and 100 kΩ pull-up on SDO for busy indication. This ensures valid evaluation of the AD7091's specified −40°C to +125°C operation, 1 MSPS throughput with 50 MHz SCLK, and power-down mode current (324 nA at 3 V).

Key Specifications

Availability

EVAL-AD7091SDZ is available at Aetrix Electronics and suitable for precision data acquisition systems, portable medical diagnostics, and low-power industrial monitoring requiring stable component supply, traceable evaluation hardware, and documented signal-chain validation paths.

Supply support for EVAL-AD7091SDZ 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 engineering centers worldwide.

The EVAL-AD7091SDZ belongs to Analog Devices' precision data acquisition evaluation platform family, designed specifically to accelerate development of ultralow-power, high-accuracy sensor interfaces for battery-constrained and thermally demanding applications.

FAQ

What is the primary function of the EVAL-AD7091SDZ evaluation board?

The EVAL-AD7091SDZ is a dedicated evaluation platform for the AD7091 12-bit SAR ADC. It provides a complete, layout-optimized circuit enabling engineers to validate key performance metrics-including INL (±1 LSB), power consumption (367 µA at 3 V/1 MSPS), SNR (69.84 dB), and timing compliance-under real-world conditions. The board is not a standalone product but a tool to verify the AD7091's behavior before integration into final designs.

Does the EVAL-AD7091SDZ support the AD7091's power-down mode and busy indicator functionality?

Yes, the EVAL-AD7091SDZ fully supports both features. A 100 kΩ pull-up resistor on the SDO line enables the busy indicator as described in the AD7091 datasheet Figure 19. Power-down mode is activated by holding CONVST low prior to end-of-conversion (EOC), and the board's unmodified signal routing preserves the 324 nA typical power-down current at 3 V specified in Table 1.

Can the EVAL-AD7091SDZ be used with supply voltages outside the AD7091's 2.09 V to 5.25 V range?

No. The EVAL-AD7091SDZ is designed exclusively for the AD7091's validated operating range. Applying voltage outside 2.09 V to 5.25 V violates the AD7091's Absolute Maximum Ratings (Table 3), risks permanent damage, and invalidates all published specifications-including INL, SNR, and power consumption-for the EVAL-AD7091SDZ system.

How does the EVAL-AD7091SDZ ensure accurate dynamic performance measurement?

The EVAL-AD7091SDZ implements Analog Devices' recommended layout: low-inductance VDD decoupling (10 µF + 0.1 µF), 1 µF REGCAP bypass, and a 51 Ω + 4.7 nF RC filter on VIN. This preserves the AD7091's specified 1.2 MHz full-power bandwidth and enables repeatable measurement of THD (−81.05 dB) and SFDR (−75 dB) per Figures 4 and 8, avoiding degradation from source impedance or clock feedthrough.

Is the EVAL-AD7091SDZ compatible with standard microcontroller SPI interfaces?

Yes. The EVAL-AD7091SDZ exposes all required signals-CONVST, CS, SCLK, and SDO-in standard 0.1″ headers, supporting direct connection to MCU SPI peripherals. Its timing complies with AD7091 Table 2 specifications, including t2 (7 ns data access), t3/t5 (0.4×tSCLK pulse widths), and tQUIET (50 ns minimum), ensuring reliable 12-bit MSB-first data capture at up to 50 MHz SCLK.