Analog Devices Inc. DC1908A-B

Overview

DC1908A-B from Analog Devices (formerly Linear Technology) is a fully assembled, production-ready evaluation board for the LTC2337-18 18-bit, 500ksps successive approximation register (SAR) analog-to-digital converter. It provides complete signal chain support-including precision ±10.24V true bipolar differential input conditioning, onboard 2.048V reference with buffered 4.096V output, and SPI-compatible serial interface-with validated layout, decoupling, and thermal design for high-SNR data acquisition. It is used to prototype industrial process control and high-speed test equipment.

For engineers reviewing the DC1908A-B datasheet, DC1908A-B pinout, DC1908A-B application, or DC1908A-B equivalent, this page delivers verified board-level specifications, supply support details, manufacturer context, and answers to common integration questions-including CNV timing validation, REFBUF startup behavior, daisy-chain configuration, sleep mode current measurement, and compatibility with LTC6655-2.048 external references.

Technical Context

The DC1908A-B implements the LTC2337-18 in a 16-lead MSOP package with full analog front-end support: low-noise RC filtering on IN+/IN–, 47µF/100nF decoupling on REFBUF/REFIN, and 2.2µF/10µF/0.1µF bypassing on VDDLBYP/VDD/OVDD. It supports all three reference configurations-internal only, externally overdriven REFIN, and disabled internal buffer with external REFBUF drive-and includes jumpers for CHAIN mode selection and RDL/SDI bus enable control.

Board-level timing is synchronized to the LTC2337-18's internal oscillator; no external clock is required. The BUSY and CNV signals are accessible via SMA connectors and test points, and SDO/SCK/RDL/SDI are routed to a 16-pin header compatible with standard SPI host controllers. Power sequencing follows VDD → OVDD → CNV assertion, with nap/sleep modes fully functional and measurable via on-board current sense resistors.

Key Specifications

Availability

DC1908A-B is available at Aetrix Electronics and suitable for industrial process control, high-speed data acquisition systems, automated test equipment (ATE), and portable instrumentation requiring stable component supply, traceable sourcing, and long-term lifecycle continuity.

Supply support for DC1908A-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 semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control applications.

The DC1908A-B belongs to ADI's Linear Technology evaluation board portfolio, designed to accelerate prototyping and validation of high-resolution data converters in demanding industrial, test, and instrumentation environments.

FAQ

What is the purpose of the DC1908A-B evaluation board?

The DC1908A-B evaluation board is a production-grade platform for rapid characterization and system integration of the LTC2337-18 18-bit, 500ksps SAR ADC. It provides fully validated analog signal conditioning, reference circuitry, power delivery, and SPI interface routing-enabling engineers to verify timing margins, measure SNR/THD under real-world conditions, validate daisy-chain operation, and evaluate sleep mode power savings without custom PCB development. DC1908A-B eliminates layout risk for critical high-speed ADC interfaces.

Does DC1908A-B support external reference overdrive, and how is it configured?

Yes, DC1908A-B supports external reference overdrive on both REFIN (1.25V–2.4V) and REFBUF (2.5V–5V) pins. To use an external reference on REFIN, remove the 0Ω jumper on JP1 and connect the source to TP1 (REFIN); the internal buffer remains active, scaling output to 2×. To disable the internal buffer and drive REFBUF directly, ground REFIN (via JP2) and apply voltage to TP2 (REFBUF). DC1908A-B includes test points and footprints for LTC6655-2.048 and similar precision references.

How is daisy-chain mode enabled on DC1908A-B, and what connections are required?

Daisy-chain mode on DC1908A-B is enabled by setting JP3 (CHAIN) to HIGH (3.3V or 5V), which configures RDL/SDI as serial data input. SDO from a preceding device connects to RDL/SDI (TP3), while SDO (TP4), SCK (TP5), and BUSY (TP6) remain outputs. The board supports up to four devices in chain mode using the same SCK and BUSY lines; CNV must be asserted synchronously across all devices. DC1908A-B includes series resistors and termination options to maintain signal integrity in multi-drop configurations.

Can DC1908A-B operate in sleep mode, and how is sleep current measured?

Yes, DC1908A-B fully supports the LTC2337-18's sleep mode (300μW typical). To enter sleep mode, hold CNV LOW for >100ns after conversion completes; the part automatically transitions when idle. Sleep current is measured by opening Jumper JP4 to isolate the VDD supply path and inserting a multimeter between TP7 (VDD_IN) and TP8 (VDD_OUT), with OVDD powered and all other signals static. DC1908A-B includes Kelvin traces and 0.1Ω sense resistors for accurate low-current measurement without loading effects.

Is the DC1908A-B compatible with the LTC6655-2.048 external reference, and how is it connected?

Yes, DC1908A-B is explicitly designed for compatibility with the LTC6655-2.048. To use it, remove JP1 (REFIN jumper), ground REFIN via JP2, and connect the LTC6655-2.048 output to TP2 (REFBUF). Bypass the LTC6655-2.048 with a 2.7μF–100μF X7R ceramic capacitor near TP2, and ensure the REFBUF decoupling capacitor (C11, 47μF) remains installed. This configuration achieves ±10.24V input range with <2ppm/°C drift and 0.025% initial accuracy-validated per LTC2337-18 datasheet Table 2.