Analog Devices Inc. DC1620A-A

Overview

DC1620A-A from Analog Devices (formerly Linear Technology) is a 64-pin QFN evaluation board for the LTC2185 dual 16-bit, 125Msps analog-to-digital converter. It provides full access to differential analog inputs, LVDS/CMOS digital outputs, SPI configuration, and clock conditioning circuitry - enabling high-fidelity IF sampling in software-defined radio and communications test systems.

For engineers reviewing the DC1620A-A datasheet, DC1620A-A pinout, DC1620A-A application, or DC1620A-A equivalent, this board supports rapid validation of SNR (76.8dB), SFDR (90dB), ultralow jitter (0.07psRMS), dual-channel simultaneous sampling, and flexible output modes (DDR LVDS, DDR CMOS, full-rate CMOS) under real-world RF front-end conditions.

Technical Context

The DC1620A-A implements a complete signal chain interface for the LTC2185 ADC, featuring on-board ultra-low-jitter clock conditioning (including optional duty cycle stabilizer), matched 50Ω differential analog input paths with transformer-coupled and AC-coupled options, and configurable termination for DDR LVDS outputs. It supports both single-ended and differential encode clocking via SMA connectors.

Board-level design includes independent power regulation for VDD (1.8V analog) and OVDD (1.2V/1.5V/1.8V digital), precision reference decoupling (REFH/REFL), and exposed thermal pad soldering for thermal management - all aligned with LTC2185's 150°C T_JMAX and 20°C/W θ_JA specification.

Key Specifications

Availability

DC1620A-A is available at Aetrix Electronics and suitable for cellular base station prototyping, SDR transceiver development, and portable medical imaging system validation requiring stable component supply and traceable evaluation hardware.

Supply support for DC1620A-A 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 technologies, serving communications, industrial, automotive, and healthcare markets.

The DC1620A-A belongs to ADI's Linear Technology legacy evaluation board family, designed specifically to accelerate time-to-test for high-speed data converters - emphasizing signal integrity, layout fidelity, and out-of-box usability for RF and IF sampling applications.

FAQ

What is the primary function of the DC1620A-A evaluation board?

The DC1620A-A evaluation board is a fully assembled and tested platform for the LTC2185 dual 16-bit, 125Msps analog-to-digital converter. Its purpose is to enable immediate characterization of dynamic performance metrics - including SNR (76.8dB), SFDR (90dB), and jitter (0.07psRMS) - under real-world clock and analog input conditions without custom PCB development. The DC1620A-A includes all necessary power regulation, clock conditioning, and I/O interfacing to validate the LTC2185 in demanding communications applications.

Does the DC1620A-A support both CMOS and LVDS output modes for the LTC2185?

Yes, the DC1620A-A supports all three digital output configurations specified for the LTC2185: full-rate CMOS, double-data-rate (DDR) CMOS, and DDR LVDS. Jumpers and onboard terminations allow users to configure output drive strength (e.g., 3.5mA vs. 1.75mA LVDS), OVDD voltage (1.2V/1.5V/1.8V), and data format (parallel or DDR) - directly matching the LTC2185's register-controlled output mode selection. This flexibility ensures accurate timing and signal integrity validation across interface types.

Can the DC1620A-A be used with the LTC2184 or LTC2183 ADCs?

No - the DC1620A-A is specifically designed and optimized for the LTC2185 (125Msps variant). While the LTC2184 (105Msps) and LTC2183 (80Msps) share the same 64-pin QFN package and core architecture, the DC1620A-A's clock distribution network, power delivery, and layout are tuned for 125Msps operation and may not guarantee optimal performance or stability at lower sample rates without modification. For those variants, Analog Devices provides dedicated boards: DC1620A-B (LTC2184) and DC1620A-C (LTC2183).

What clock sources are compatible with the DC1620A-A?

The DC1620A-A accepts differential (LVDS, LVPECL) or single-ended (CMOS, TTL) clock signals via SMA connectors, supporting encode frequencies up to 125MHz. It includes an onboard clock duty cycle stabilizer and optional external clock buffer path. The board also supports crystal oscillator input (for fixed-frequency reference) and provides CLKOUT± outputs synchronized to the ADC sampling edge - enabling precise timing correlation between the DC1620A-A and external FPGA or processor logic.

How is analog input common-mode bias handled on the DC1620A-A?

The DC1620A-A routes the LTC2185's internal VCM1 and VCM2 outputs (nominally VDD/2 = 0.9V) to the analog input transformers, establishing correct common-mode voltage for differential signaling. Each channel features separate 0.1µF ceramic bypassing at the VCM pins and uses center-tapped transformers to maintain balanced drive while rejecting common-mode noise - ensuring compliance with the LTC2185's ±0.5V common-mode tolerance and enabling accurate 1VP-P to 2VP-P input range selection without external bias networks.