Analog Devices Inc. EVAL-AD7887SDZ

Overview

EVAL-AD7887SDZ from Analog Devices is an evaluation board designed to characterize and prototype the AD7887 - a 12-bit, 125 kSPS, micropower SAR ADC in 8-lead MSOP. It supports single/dual-channel operation, 2.7 V–5.25 V supply, SPI/QSPI/MICROWIRE-compatible serial interface, and internal 2.5 V reference. Used for rapid validation of battery-powered data acquisition systems.

For engineers reviewing the EVAL-AD7887SDZ datasheet, EVAL-AD7887SDZ pinout, EVAL-AD7887SDZ application, or EVAL-AD7887SDZ equivalent, this board enables functional verification of the AD7887's dynamic performance (71 dB SNR), low-power modes (1 μA shutdown), dual-input sampling, and reference flexibility (internal/external VREF) in real-world signal chains.

Technical Context

The EVAL-AD7887SDZ provides direct access to all AD7887 signals - including AIN0, AIN1/VREF, CS, SCLK, DIN, DOUT, VDD, and GND - via solderable test points and header pins. It implements proper analog/digital ground separation, decoupling (0.1 µF + 10 µF at VDD), and ESD-protected input paths aligned with AD7887's ±5 µA input leakage and 20 pF input capacitance.

Board-level design mirrors AD7887's operational constraints: supports 2 MHz SCLK timing (tCONVERT = 7.25 µs), accommodates both single-ended input configurations (0–VREF or 0–VDD range), and enables all four power management modes (shutdown, standby, normal, auto-power-down) via configurable logic levels on CS and DIN.

Key Specifications

Availability

EVAL-AD7887SDZ is available at Aetrix Electronics and suitable for battery-powered instrumentation, portable medical devices, and industrial sensor interface designs requiring stable component supply and fast evaluation turnaround.

Supply support for EVAL-AD7887SDZ 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.

EVAL-AD7887SDZ belongs to Analog Devices' precision data acquisition evaluation platform family, engineered to accelerate development of low-power, high-accuracy measurement systems for portable and energy-constrained applications.

FAQ

What is the primary function of EVAL-AD7887SDZ?

EVAL-AD7887SDZ is an evaluation board specifically designed for the AD7887 12-bit SAR ADC. It provides a ready-to-use platform to evaluate the device's performance-including 125 kSPS throughput, 71 dB SNR, dual/single-channel operation, and 1 μA shutdown mode-without custom PCB design. The EVAL-AD7887SDZ includes all necessary decoupling, signal routing, and interface headers to connect directly to microcontrollers or logic analyzers.

Does EVAL-AD7887SDZ support both single-ended input configurations of the AD7887?

Yes, EVAL-AD7887SDZ fully supports both configurations. In single-channel mode, AIN0 accepts 0–VREF inputs (with VREF sourced internally at 2.5 V or externally applied to AIN1/VREF). In dual-channel mode, both AIN0 and AIN1 accept 0–VDD inputs, with VDD serving as the reference. The board exposes all control lines (CS, DIN, SCLK) to allow software configuration of the AD7887's SIN/DUAL and REF bits via its 8-bit control register.

Can EVAL-AD7887SDZ be used with an external reference voltage?

Yes, EVAL-AD7887SDZ allows direct connection of an external reference (1.2 V to VDD) to the AIN1/VREF pin. When the AD7887's REF bit is set to '1', the internal 2.5 V reference is disabled, enabling precise control over full-scale range and improved noise immunity. The board's layout maintains low-impedance routing and bypassing to preserve reference stability and minimize PSRR degradation.

What power management modes of the AD7887 are accessible via EVAL-AD7887SDZ?

EVAL-AD7887SDZ enables all four AD7887 power modes: Mode 1 (CS-controlled shutdown), Mode 2 (always-on), Mode 3 (auto-shutdown after conversion), and Mode 4 (standby with reference active). Jumpers and test points let users assert CS, DIN, and SCLK states to select PM1/PM0 bits per Table 6 in the AD7887 datasheet, verifying current draw down to 1 μA in shutdown and 210 μA in standby.

Is EVAL-AD7887SDZ compatible with standard microcontroller SPI interfaces?

Yes, EVAL-AD7887SDZ implements a standard 4-wire SPI interface (CS, SCLK, DIN, DOUT) fully compatible with SPI, QSPI, MICROWIRE, and DSP protocols. It uses MSB-first straight-binary output with four leading zeros followed by 12 data bits, clocked on SCLK falling edge. Timing aligns with AD7887's t3 (75 ns max DOUT access time) and t4/t5 (20 ns setup/hold), supporting up to 2 MHz SCLK without modification.