Analog Devices Inc. DC873A

Overview

DC873A from Analog Devices is a demonstration board for the LTC1867 16-bit, 8-channel, 200ksps successive-approximation ADC with internal 2.5V reference and SPI/MICROWIRE interface. It supports single-ended or differential analog inputs, unipolar/bipolar conversion modes, and operates from a single 5V supply. The board enables rapid evaluation of high-precision data acquisition in industrial process control and battery-operated systems.

For engineers reviewing the DC873A datasheet, DC873A pinout, DC873A application, or DC873A equivalent, this page provides verified hardware configuration details, supported ADC variants (LTC1867/LTC1867A), real-world timing behavior under nap/sleep modes, and layout-critical bypassing guidance for SNR-sensitive 89dB applications.

Technical Context

The DC873A implements the LTC1867 ADC in a fully populated, ready-to-run configuration with on-board 2.5V VREF and 4.096V REFCOMP buffers, 10µF/0.1µF bypassing per Analog Devices' recommended layout, and direct connection to a host microcontroller via standard SPI header (CS/CONV, SCK, SDI, SDO). It supports all LTC1867 input multiplexer configurations - including CH7/COM as common-mode reference or independent channel - and validates automatic nap mode current reduction (1.3mA → 150µA) between conversions.

Board-level design enforces strict analog-digital separation: dedicated ground plane, shielded analog input traces, and physically isolated digital signal routing. The board accepts both internal reference operation and external reference injection via VREF/REFCOMP pins, enabling verification of ±0.5ppm/°C offset drift and ±15ppm/°C gain tempco performance across –40°C to +85°C.

Key Specifications

Availability

DC873A is available at Aetrix Electronics and suitable for industrial process control, high-speed data acquisition, and battery-operated systems requiring stable component supply and validated reference design implementation.

Supply support for DC873A 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, serving industrial, automotive, communications, and healthcare markets.

The DC873A belongs to Analog Devices' precision data acquisition evaluation platform family, designed to accelerate validation of high-resolution ADCs in noise-sensitive, low-power, and thermally demanding applications.

FAQ

What is the primary function of the DC873A evaluation board?

The DC873A evaluation board is a fully assembled and tested hardware platform for evaluating the LTC1867 16-bit, 8-channel, 200ksps analog-to-digital converter. It provides immediate access to all ADC features - including configurable MUX, internal reference, SPI interface, nap/sleep modes - with optimized layout and bypassing to achieve the datasheet's 89dB SNR and ±2LSB INL specifications. DC873A does not contain an IC itself but hosts the LTC1867.

Which ADC variants are supported by the DC873A board?

The DC873A board supports the LTC1867 (–40°C to +85°C, ±2LSB INL) and LTC1867A (–40°C to +85°C, ±2.5LSB INL) in the 16-pin narrow SSOP package. It is not compatible with the 12-bit LTC1863. Board silkscreen and documentation confirm LTC1867-specific component placement, reference buffer tuning, and timing validation for 200ksps operation.

Does the DC873A include on-board power regulation for the LTC1867?

No, the DC873A requires an external 5V ±5% supply applied to its VDD header. It does not include voltage regulation circuitry. The board routes that 5V directly to the LTC1867's VDD pin and to all required bypass capacitors (10µF tantalum + 0.1µF ceramic on VDD, VREF, and REFCOMP), following Analog Devices' layout guidelines to maintain PSRR and minimize switching noise coupling into the analog section.

How does the DC873A validate the LTC1867's automatic nap mode functionality?

The DC873A enables nap mode verification through its default CS/CONV timing configuration: after conversion completion, CS/CONV remains high, causing the LTC1867 to enter nap mode and reduce supply current from 1.3mA to 150µA. Current draw can be measured at the VDD test point, and timing compliance (t1, t2, t3, t4) is confirmed using the onboard SPI header signals. Nap mode behavior is documented in the DC873A user guide (UG-123).

Can the DC873A be used to evaluate external reference configurations?

Yes, the DC873A provides dedicated test points and jumper options to disconnect the internal 2.5V VREF and inject an external reference (e.g., LT1019A-2.5) at the VREF pin, while maintaining proper 6kΩ series resistance as specified in the LTC1867 datasheet. REFCOMP can also be overdriven externally by tying VREF to GND and applying 4.096V directly - a configuration validated in the DC873A schematic and UG-123.