Analog Devices Inc. DC966A

Overview

DC966A from Analog Devices (formerly Linear Technology) is a demonstration circuit for the LT5568 high-linearity direct quadrature modulator IC, operating from 700 MHz to 1.05 GHz RF output range with −6.8 dB conversion gain, +22.9 dBm OIP3, and −46 dBc image rejection-used in wireless infrastructure base stations for GSM, W-CDMA, and OFDM signal upconversion.

For engineers reviewing the DC966A datasheet, DC966A pinout, DC966A application, or DC966A equivalent, this page delivers verified board-level specifications, test setup guidance, supply requirements (5 V, 113 mA), RF performance metrics, and integration notes for I/Q modulator evaluation in 4G/LTE-adjacent systems.

Technical Context

The DC966A implements the LT5568 as a fully assembled, calibrated evaluation platform with matched 50 Ω RF input/output ports, differential baseband interfaces (DC–380 MHz), and single-ended LO drive (−10 to +5 dBm, 700–1050 MHz). It leverages on-chip RF transformer coupling and internal quadrature LO generation to enable image-reject modulation without external phase shifters.

Its architecture supports both direct I/Q modulation and image-reject upconverting mixer operation via externally applied 90° phase-shifted baseband signals. The board includes DC offset adjustment points to fine-tune LO leakage (<−43 dBm) and image rejection through controlled baseband amplitude/phase imbalance correction.

Key Specifications

Availability

DC966A is available at Aetrix Electronics and suitable for wireless infrastructure prototyping, RF transceiver validation, and high-linearity modulator characterization requiring stable component supply, traceable calibration history, and documented test setup reproducibility.

Supply support for DC966A 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. designs, manufactures, and markets high-performance analog, mixed-signal, and digital signal processing integrated circuits for precision instrumentation, communications, and industrial applications.

The DC966A belongs to Analog Devices' demonstration circuit portfolio targeting RF signal chain evaluation-specifically engineered to accelerate development of high-efficiency, spectrally clean wireless transmitters using the LT5568 I/Q modulator.

FAQ

What is the primary function of the DC966A demonstration circuit?

The DC966A demonstration circuit provides a fully populated, factory-tested platform for evaluating the LT5568 direct quadrature modulator. It enables rapid validation of RF upconversion performance-including conversion gain, OIP3, image rejection, and LO leakage-in real-world 700–1050 MHz wireless infrastructure applications. The DC966A includes calibrated RF and baseband interfaces, DC offset trim points, and documented measurement procedures to ensure repeatable results without custom PCB design.

Does the DC966A require external tuning or matching components for operation across its specified RF band?

No, the DC966A requires no external tuning or matching components for operation from 700 MHz to 1050 MHz. Its layout incorporates optimized 50 Ω RF routing, integrated baluns, and impedance-matched baseband paths-all validated per the LT5568 datasheet. The board achieves >30 dB RF output return loss and >13 dB LO input return loss across the full band, eliminating the need for user-adjusted stubs, capacitors, or ferrites during standard evaluation.

What baseband interface configuration does the DC966A support, and what is its common-mode voltage requirement?

The DC966A supports differential DC-coupled baseband inputs with four dedicated ports (I+, I−, Q+, Q−), each designed for a nominal 0.5 V common-mode voltage and ~100 Ω differential input impedance. This configuration matches current-output DACs and baseband processors used in wireless transceivers. The board includes accessible DC offset adjustment points to correct small imbalances that affect LO leakage and image rejection.

Can the DC966A be used to evaluate the LT5568 as an image-reject upconverting mixer?

Yes, the DC966A supports image-reject upconverting mixer operation by accepting externally generated 90° phase-shifted signals at its I and Q baseband inputs-enabling configuration beyond standard I/Q modulation. The board's low-phase-noise LO path, calibrated baseband termination, and symmetric layout preserve quadrature fidelity, allowing accurate measurement of image suppression (−46 dBc typical) and sideband asymmetry under mixer-mode conditions.

What power supply requirements must be met to operate the DC966A reliably?

The DC966A requires a stable 4.5 V to 5.25 V DC supply capable of delivering ≥150 mA peak current, with recommended current limiting set to 150 mA during initial power-up. At 5 V, it draws 113 mA in active mode and reduces to 230 µA in shutdown (EN = low). Reverse-polarity protection and input filtering are implemented onboard, but lab-grade low-noise supplies are advised to minimize spurious contributions during distortion measurements.