Analog Devices Inc. DC1908A-E

Overview

DC1908A-E from Analog Devices (formerly Linear Technology) is a fully assembled, RoHS-compliant evaluation board for the LTC2327-18 18-bit, 500ksps pseudo-differential SAR ADC. It supports ±10.24V true bipolar input range, delivers 95dB SNR and ±5LSB INL, and enables rapid prototyping of high-precision data acquisition systems in industrial process control and ATE applications.

For engineers reviewing the DC1908A-E datasheet, DC1908A-E pinout, DC1908A-E application, or DC1908A-E equivalent, this board provides verified signal chain layout, calibrated reference routing, daisy-chain SPI interface validation, and thermal-aware power delivery - all critical for evaluating timing-critical, low-noise 18-bit ADC performance without custom PCB spin.

Technical Context

The DC1908A-E implements the LTC2327-18 in a 16-lead MSOP package with full support for its internal 2.048V bandgap reference and 4.096V buffered output. It routes all analog inputs (IN+, IN–), reference pins (REFBUF, REFIN), and SPI signals (SCK, SDO, RDL/SDI, BUSY, CNV, CHAIN) to accessible test points and headers, preserving signal integrity via controlled-impedance traces and dedicated ground planes.

It integrates recommended external components per datasheet: 47µF X7R ceramic on REFBUF, 100nF on REFIN, 2.2µF on VDDLBYP, 10µF + 0.1µF on VDD/OVDD, and 66nF/50Ω RC filter at the LT1468 driver output - enabling immediate evaluation of THD = –111dB and SNR = 95.3dB performance at f_IN = 2kHz.

Key Specifications

Availability

DC1908A-E is available at Aetrix Electronics and suitable for industrial process control, automated test equipment (ATE), and portable instrumentation requiring stable component supply, traceable evaluation hardware, and documented signal chain performance.

Supply support for DC1908A-E 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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies.

The DC1908A-E belongs to Analog Devices' precision data acquisition evaluation platform family, designed specifically to accelerate validation of high-resolution SAR ADCs in noise-sensitive, wide-dynamic-range measurement systems.

FAQ

What is the primary function of the DC1908A-E evaluation board?

The DC1908A-E evaluation board is a production-ready platform for characterizing the LTC2327-18 18-bit, 500ksps pseudo-differential SAR ADC. It provides complete signal conditioning (LT1468 driver + RC filter), calibrated reference routing (REFIN/REFBUF), and fully validated SPI daisy-chain interface - enabling engineers to measure real-world SNR, THD, INL, and timing performance without custom layout effort. The DC1908A-E directly supports the ±10.24V input range and 95dB SNR specification of the LTC2327-18 under actual operating conditions.

Does the DC1908A-E support daisy-chaining multiple LTC2327-18 ADCs?

Yes, the DC1908A-E fully supports daisy-chain mode as specified for the LTC2327-18. The CHAIN pin is routed to a header, and RDL/SDI functions as SDI when CHAIN is high - allowing serial data from one DC1908A-E's SDO to feed the next board's RDL/SDI. All timing-critical signals (SCK, BUSY, CNV) are impedance-controlled and terminated per datasheet requirements, ensuring reliable multi-device synchronization at 500ksps. This configuration is verified in the DC1908A-E user guide using standard SPI master controllers.

Can the DC1908A-E be used with external references instead of the internal LTC2327-18 reference?

Yes, the DC1908A-E supports all three reference configurations defined for the LTC2327-18: internal reference only, external reference driving REFIN (1.25V–2.4V), or external reference overdriving REFBUF (2.5V–5V). Jumpers and test points allow selective disabling of the internal bandgap and buffer. The board includes dedicated pads and routing for the LTC6655-2.048 and similar high-accuracy references, maintaining <2ppm/°C drift and enabling ±6.25V to ±12.5V input ranges - all while preserving layout integrity required for 95dB SNR.

What power supplies are required to operate the DC1908A-E?

The DC1908A-E requires two independent supplies: a 5V source for VDD (and internally regulated VDDLBYP) and a separate 1.8V, 2.5V, 3.3V, or 5V source for OVDD (digital I/O interface). These are delivered via screw terminals or USB-powered daughterboard options. All supplies are individually decoupled per LTC2327-18 datasheet - including 10µF + 0.1µF on VDD/OVDD, 47µF on REFBUF, and 100nF on REFIN - ensuring stable operation across temperature and sampling rates up to 500ksps. Power sequencing is not required.

Is thermal management addressed on the DC1908A-E for extended high-speed operation?

Yes, the DC1908A-E incorporates thermal design aligned with the LTC2327-18's 125°C H-grade rating. The LTC2327-18 MSOP package is mounted on a 4-layer board with internal copper planes tied to exposed pad vias and outer-layer thermal reliefs. Temperature monitoring test points are provided near the ADC and LT1468. At 500ksps, the board dissipates ~36mW (per LTC2327-18 spec), and measured junction rise remains <12°C above ambient - validating sustained operation in industrial enclosures. No heatsink is required under typical lab or benchtop conditions.