Analog Devices Inc. DC733A

Overview

DC733A from Analog Devices (formerly Linear Technology) is a demonstration board for the LT5519 high-linearity upconverting mixer IC, designed for wireless infrastructure transmitters operating from 700MHz to 1400MHz RF output. It supports single-ended LO and IF operation, integrates an on-chip 50Ω-matched RF output transformer, and delivers +17.1dBm typical input IP3 at 1GHz with 5V supply.

For engineers reviewing the DC733A datasheet, DC733A pinout, DC733A application, or DC733A equivalent, this page provides verified layout details, measured RF performance data, test circuit configuration, thermal management guidance for the exposed-pad QFN, and design considerations for IF/LO/RF port matching across 1–400MHz IF and 700–1400MHz RF bands.

Technical Context

The DC733A implements the LT5519 in a fully populated, production-ready 4mm × 4mm QFN-16 evaluation layout with optimized RF grounding, controlled-impedance IF/LO/RF traces, and discrete external matching components (220pF C1/C2, 33pF C3, 39nH L1, 100Ω R1/R2, ETC4-1-2 4:1 balun). It validates the IC's single-ended LO drive capability (–5dBm), differential IF input biasing (18mA per side), and transformer-coupled RF output (50Ω matched without external components above 850MHz).

Board-level features include three independent VCC supply rails (VCC1 for bias, VCC2 for LO buffer, VCC3 for mixer core), EN-controlled enable/disable with 2µs turn-on time, and thermal management via soldered exposed pad (Pin 17) connected to internal ground plane. Performance is characterized per Figure 2 of the LT5519 datasheet at TA = 25°C with fIF = 140MHz, fLO = 1140MHz, fRF = 1000MHz.

Key Specifications

Availability

DC733A is available at Aetrix Electronics and suitable for wireless infrastructure transmitter design, cable downlink infrastructure development, and point-to-point communication system prototyping requiring stable component supply and production-representative RF evaluation.

Supply support for DC733A 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 RF ICs for precision signal processing applications.

The DC733A belongs to Analog Devices' evaluation board product line, engineered to accelerate RF system development by providing validated layouts, calibrated measurement data, and application-specific component selection for high-linearity mixer ICs used in cellular base stations and broadband transmission equipment.

FAQ

What is the primary function of the DC733A evaluation board?

The DC733A evaluation board is a fully assembled demonstration platform for the LT5519 upconverting mixer IC. It enables rapid validation of RF upconversion performance-including conversion gain, input IP3 (+17.1dBm), noise figure (13.6dB), and LO-to-RF leakage (–44dBm)-in real-world wireless infrastructure transmitter configurations. The DC733A implements the reference test circuit from the LT5519 datasheet with all critical passive components, power routing, and thermal grounding pre-optimized.

Does the DC733A support both high-side and low-side LO injection?

Yes, the DC733A supports both high-side and low-side LO injection as confirmed by LT5519 datasheet Figures G04 and G05, which show IIP3, IIP2, and LO-RF leakage versus RF output frequency under both injection modes. The board's fixed component values (C1/C2 = 220pF, C3 = 33pF) are tuned for 140MHz IF and 1140MHz LO to produce 1000MHz RF output, but the underlying LT5519 architecture on the DC733A allows reconfiguration for alternate LO frequencies within the 300–1800MHz range.

How is thermal management implemented on the DC733A for the LT5519 IC?

The DC733A implements thermal management via direct soldering of the LT5519's exposed pad (Pin 17) to the PCB's internal ground plane, as required by the LT5519 datasheet. This exposed pad serves as the primary DC and RF ground return path and must be connected to a low-impedance thermal mass. The board layout follows Linear Technology's recommended pad dimensions (2.15mm × 2.15mm) and solder stencil specifications to ensure reliable thermal conduction and mechanical stability during RF operation.

Can the DC733A be used to evaluate IF frequencies outside the default 140MHz setting?

Yes, the DC733A can evaluate IF frequencies from 1MHz to 400MHz by modifying external matching components per Table 4 in the LT5519 datasheet. For example, changing C1 and C2 from 220pF (140MHz) to 68pF enables 240MHz IF operation, while reducing C3 from 33pF to 15pF improves LO-to-RF leakage at higher IF frequencies. All capacitor footprints on the DC733A are 0402-size, allowing straightforward rework to match target IF bands.

What is the role of the 4:1 balun (M/A-COM ETC4-1-2) on the DC733A?

The 4:1 balun (M/A-COM ETC4-1-2) on the DC733A transforms the LT5519's differential 10.2Ω IF input impedance to a nominal 50Ω single-ended source interface, enabling connection to standard RF test equipment. As specified in LT5519 datasheet Table 1, the IF port exhibits ~10Ω differential impedance with constant S11 magnitude (0.663) across 10–500MHz; the balun provides the necessary impedance transformation and common-mode rejection to maintain optimal LO leakage performance and conversion gain.