Analog Devices Inc. DC1805A-B

Overview

DC1805A-B from Analog Devices (formerly Linear Technology) is a fully assembled, tested, and documented evaluation board for the LTC2378-16 16-bit, 1Msps SAR ADC. It provides a complete signal chain-including precision reference, low-noise power supplies, differential input driver, and SPI interface-enabling immediate characterization of dynamic performance (97dB SNR, ±0.5LSB INL) in high-speed data acquisition systems.

For engineers reviewing the DC1805A-B datasheet, DC1805A-B pinout, DC1805A-B application, or DC1805A-B equivalent, this board supports rapid validation of the LTC2378-16 under real-world conditions-including daisy-chain SPI operation, digital gain compression (DGC) mode, and full-temperature-range testing up to 125°C.

Technical Context

The DC1805A-B implements the LTC2378-16 in its 16-lead DFN package with exposed pad, using a 5V reference (LT6657), dual-rail ±5V analog supply (LT3045/LT3094), and single-ended-to-differential driver (LT6350). It supports both normal and chain-mode SPI communication via on-board headers and includes jumpers for REF/DGC configuration, CNV timing control, and input coupling selection (AC/DC).

Board-level design incorporates 47µF X5R ceramic decoupling at REF, 10µF at VDD, and 0.1µF at OVDD per datasheet recommendations; analog input traces are length-matched and shielded to preserve 34MHz –3dB bandwidth and minimize aperture jitter (4ps typical).

Key Specifications

Availability

DC1805A-B is available at Aetrix Electronics and suitable for high-speed data acquisition, portable instrumentation, industrial process control, and ATE applications requiring stable component supply and validated reference designs.

Supply support for DC1805A-B 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. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, formed through the acquisition of Linear Technology in 2017.

The DC1805A-B belongs to ADI's Linear Technology Evaluation Board product line, designed to accelerate prototyping and validation of precision data converters-including SAR ADCs optimized for low power, high SNR, and wide input voltage ranges.

FAQ

What is the primary function of the DC1805A-B evaluation board?

The DC1805A-B evaluation board is a ready-to-use platform for evaluating the LTC2378-16 16-bit, 1Msps SAR ADC. It provides all necessary support circuitry-including precision reference, low-noise analog supplies, differential input driver, and configurable SPI interface-to measure key performance metrics such as SNR, THD, INL, and DNL without custom hardware development. The DC1805A-B enables immediate lab validation of the LTC2378-16 under specified operating conditions.

Does the DC1805A-B support digital gain compression (DGC) mode for the LTC2378-16?

Yes, the DC1805A-B supports DGC mode via a dedicated jumper (JP1) that connects the REF/DGC pin of the LTC2378-16 to GND. When enabled, DGC maps the full-scale input range to 10%–90% of ±VREF (e.g., 0.5V–4.5V for 5V reference), allowing single-supply operation of the LT6350 driver. This configuration is fully documented in the DC1805A-B user guide and verified with FFT measurements showing maintained 95.5dB SNR.

Can the DC1805A-B be used to evaluate the LTC2378-16 at extended temperature ranges?

Yes-the DC1805A-B board layout and component selection (including LT6657 reference, LT3045/LT3094 regulators, and LT6350 driver) are qualified for operation from –40°C to +125°C, matching the H-grade temperature range of compatible LTC2378-16 variants (e.g., LTC2378HMS-16 and LTC2378HDE-16). Thermal vias under the DFN package ensure reliable heat dissipation during high-throughput operation.

What input signal types does the DC1805A-B support for the LTC2378-16?

The DC1805A-B supports both single-ended and fully differential input signals via its LT6350-based front-end. Jumper-selectable configurations allow evaluation of 0V–5V single-ended inputs (with level shift to ±5V differential) or true bipolar ±10V inputs (attenuated and level-shifted to match the LTC2378-16's ±VREF range). Input coupling (AC/DC) and termination options are also provided for flexible signal source integration.

How is SPI communication implemented on the DC1805A-B for the LTC2378-16?

The DC1805A-B implements SPI communication via standard 0.1"-spaced headers compatible with Analog Devices' DC2026 demonstration controller or third-party microcontrollers. It supports both normal mode (RDL/SDI as bus enable) and daisy-chain mode (RDL/SDI as serial data input) via the CHAIN pin jumper. SCK, SDO, and BUSY signals are routed to test points for oscilloscope verification, and timing complies with LTC2378-16 specifications (tSCK ≤ 10ns, tDSDO ≤ 9.5ns).