Analog Devices Inc. DC1545A-B

Overview

DC1545A-B from Analog Devices (formerly Linear Technology) is an evaluation board for the LT5578 high-linearity upconverting mixer IC, supporting RF output frequencies from 0.4GHz to 2.7GHz. It enables rapid prototyping of LTE, W-CDMA, and WiMAX transmitter stages with verified performance at 740MHz, 900MHz, and 1950MHz under single 3.3V supply operation.

For engineers reviewing the DC1545A-B datasheet, DC1545A-B pinout, DC1545A-B application, or DC1545A-B equivalent, this board provides validated RF/IF/LO matching networks, thermal management via exposed-pad soldering, and documented test circuits for conversion gain, OIP3, and noise figure characterization across infrastructure frequency bands.

Technical Context

The DC1545A-B implements the LT5578 in a fixed-layout configuration optimized for three key RF bands: 740MHz (high-side LO at 880MHz), 900MHz (low-side LO at 760MHz), and 1950MHz (high-side LO at 2190MHz). Each band uses discrete matching components-TC4-1W+ 4:1 IF transformer, 13.7Ω precision resistors, 100nH inductors, and frequency-specific capacitors-to achieve >10dB return loss on IF, LO, and RF ports.

Board-level design incorporates strict RF grounding: all 21 GND pins and the exposed pad (Pin 25) are connected to a low-impedance top-layer ground plane with multiple vias to internal layers. The layout follows Figure 12 in the LT5578 datasheet, with controlled trace lengths (e.g., TL1/TL2 = 1.9mm for 740MHz) and component placement minimizing parasitic coupling between IF+, IF–, LO, and RF paths.

Key Specifications

Availability

DC1545A-B is available at Aetrix Electronics and suitable for LTE basestation development, wireless repeater design, and public safety radio prototyping requiring stable component supply and pre-validated RF performance.

Supply support for DC1545A-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 acquired Linear Technology in 2017 and maintains its high-performance RF product portfolio, including mixers, modulators, and demodulators for wireless infrastructure.

The DC1545A-B belongs to Linear Technology's evaluation board family, designed specifically to accelerate RF front-end development for cellular base stations and broadband wireless systems using LT5578 and related signal chain components.

FAQ

What is the primary function of the DC1545A-B evaluation board?

The DC1545A-B evaluation board is a fully assembled and tested platform for the LT5578 upconverting mixer IC. It provides pre-optimized matching networks for multiple RF bands (740MHz, 900MHz, 1950MHz), enabling immediate measurement of conversion gain, OIP3, and noise figure without custom layout. DC1545A-B validates the LT5578's performance in real-world LTE and W-CDMA transmitter applications as specified in the official datasheet.

Does the DC1545A-B support both high-side and low-side LO injection?

Yes, the DC1545A-B supports both configurations: high-side LO at 880MHz for 740MHz RF output, low-side LO at 760MHz for 900MHz RF output, and high-side LO at 2190MHz for 1950MHz RF output. Matching components (C3, C13, L3) are placed per Figure 1 in the LT5578 datasheet to ensure >9dB LO return loss in each case. DC1545A-B documentation confirms these LO injection modes are implemented and characterized.

What RF output power level can be achieved with the DC1545A-B and LT5578?

The DC1545A-B enables the LT5578 to deliver RF output power up to +5dBm while maintaining linearity, as verified by IM3 measurements in the datasheet (Figure G29/G30). At 900MHz with –5dBm IF input and –1dBm LO, the board achieves 12dBm P1dB compression point and 27dBm OIP3. DC1545A-B's matching network ensures optimal power transfer into 50Ω loads across all supported bands.

How is thermal performance managed on the DC1545A-B board?

Thermal performance on the DC1545A-B is managed through direct soldering of the LT5578's exposed pad (Pin 25) to a large top-layer copper ground plane, with ≥8 thermal vias connecting to inner ground layers. This implementation achieves the datasheet-specified θJA of 34°C/W, allowing continuous operation at 152mA supply current without exceeding TJMAX = 150°C. DC1545A-B's layout strictly follows Linear Technology's thermal guidelines in Package Description (DWG #05-08-1747 Rev A).

Can the DC1545A-B be used for frequencies outside the documented bands?

The DC1545A-B is optimized for 450MHz, 740MHz, 900MHz, 1950MHz, and 2600MHz per the LT5578 datasheet Figures F08–F11. While the LT5578 itself operates from 0.4–2.7GHz, the board's fixed matching components limit usable bandwidth to these five points. For other frequencies, users must modify C/L values per Table 2–5 in the datasheet; DC1545A-B does not provide tunable elements or unused footprints for arbitrary reconfiguration.