Analog Devices Inc. DC854C-Q

Overview

DC854C-Q from Analog Devices (formerly Linear Technology) is a demonstration circuit board designed to evaluate the LTC2208-14, a 14-bit, 130 MSPS high-speed analog-to-digital converter optimized for analog input frequencies above 140 MHz. It features CMOS digital outputs, a 3.3 V supply interface, and an optimized analog input network with transformer-coupled signal path.

For engineers reviewing the DC854C-Q datasheet, DC854C-Q pinout, DC854C-Q application, or DC854C-Q equivalent, key selection considerations include its support for >140 MHz input bandwidth, fixed 14-bit resolution, CMOS output signaling, and compatibility with the DC718 QuickDAACS data acquisition system.

Technical Context

The DC854C-Q implements a transformer-coupled analog front-end using ETC1-1T flux-coupled baluns, configured for wideband operation beyond 140 MHz. Its encode clock input is AC-coupled via SMA J3 and terminated with 50 Ω, requiring low-jitter sinusoidal or square-wave drive up to 3 V_P-P.

Digital outputs are routed to a 40-pin header (J1), with bits 7–33 assigned to the 14-bit parallel CMOS data bus. Power delivery supports up to 500 mA at 3.3 V, regulated within 3.15 V to 3.45 V, and includes on-board 74VCX245 level-shifting buffers operating at 2.5 V.

Key Specifications

Availability

DC854C-Q is available at Aetrix Electronics and suitable for high-frequency test equipment, radar signal processing, and wideband communications systems requiring stable component supply and validated evaluation platform performance.

Supply support for DC854C-Q 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 semiconductors.

The DC854 series belongs to Linear's legacy demonstration circuit portfolio, engineered specifically to validate high-speed ADC performance in RF sampling and wideband digitization applications.

FAQ

What is the primary function of the DC854C-Q?

The DC854C-Q is a dedicated evaluation platform for the LTC2208-14 ADC. It provides a fully assembled, tested circuit enabling immediate characterization of dynamic performance-including SNR and SFDR-at analog input frequencies exceeding 140 MHz. The DC854C-Q includes optimized analog input coupling, CMOS output buffering, and jumper-configurable reference and gain settings to support repeatable lab validation of the LTC2208-14.

Does the DC854C-Q support LVDS output mode?

No, the DC854C-Q supports CMOS output operation only. The documentation explicitly states that LVDS output signaling is not implemented on this board and directs users to DC996 for LVDS evaluation. The DC854C-Q routes the LTC2208-14's parallel CMOS outputs directly to J1 header pins 7–33 and uses 74VCX245 buffers referenced to 2.5 V, confirming exclusive CMOS interface capability.

Which analog input transformers are used on the DC854C-Q?

The DC854C-Q uses ETC1-1T flux-coupled transformers for analog input coupling. This configuration is specified for operation above 140 MHz and differs from the ETC1-1-13 baluns used in lower-frequency variants (e.g., DC854D-A/B/C/D). The ETC1-1T enables broadband impedance matching and improved return loss in the >140 MHz band, aligning with the LTC2208-14's extended input frequency specification on this variant.

Can the DC854C-Q be powered independently of the DC718 data acquisition board?

Yes, the DC854C-Q can be powered independently via its +3.3 V and PWR GND terminals, drawing up to 500 mA. While it is commonly used with the DC718-which may supply power over USB-the board does not require the DC718 for operation. External bench supplies meeting 3.15–3.45 V and ≥500 mA specifications are fully supported, and all necessary voltage regulation and decoupling are implemented onboard the DC854C-Q.

How is the DC854C-Q configured for 14-bit operation with the LTC2208-14?

The DC854C-Q is factory-populated with the LTC2208-14 and pre-configured for 14-bit operation via hardware and software alignment. Jumper JP3 is set to GND to select the 2.25 V_PP input range, and PScope software automatically blanks the two LSBs when detecting the LTC2208-14. The 14-bit data appears on J1 pins 7–33, consistent with the pin mapping defined in the DC854C-Q schematic and Quick Start Guide.