Analog Devices Inc. DC1662A

Overview

DC1662A from Analog Devices (formerly Linear Technology) is an evaluation board for the LTC5585 RF quadrature demodulator IC, designed to demonstrate IIP2 calibration, DC offset adjustment, and wideband IF output performance up to 1 GHz. It supports 5V single-supply operation, draws ~190mA, and interfaces with standard RF test equipment via SMA connectors.

For engineers reviewing the DC1662A datasheet, DC1662A pinout, DC1662A application, or DC1662A equivalent, this demo board enables rapid validation of LTC5585-based direct-conversion receiver front-ends in microwave instrumentation, broadband communications, and spectrum monitoring systems requiring precise I/Q balance and second-order distortion control.

Technical Context

The DC1662A implements a complete signal chain around the LTC5585 - a high-linearity, 30MHz–1GHz RF-to-IF quadrature demodulator - with on-board balun (ANAREN BD0826J50200A00), DC blocking, and precision trim potentiometers for REF, IIP2I/Q, and DCOI/Q calibration. All critical RF paths are impedance-matched to 50Ω.

It provides dual calibration methods: Method 1 uses six onboard trim pots with jumper JP1 installed; Method 2 supports external voltage sources applied to REF, IP2I, IP2Q, DCOI, and DCOQ test points for automated or lab-controlled IIP2/DC offset tuning.

Key Specifications

Availability

DC1662A is available at Aetrix Electronics and suitable for RF receiver development, microwave test instrumentation, broadband spectrum analysis, and wireless infrastructure prototyping requiring stable component supply and traceable evaluation hardware.

Supply support for DC1662A 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 semiconductor leader specializing in high-performance analog, mixed-signal, and RF technologies for precision signal processing applications.

The DC1662A belongs to ADI's Linear Technology legacy evaluation board portfolio, developed specifically to accelerate design-in of high-dynamic-range RF demodulators like the LTC5585 in demanding communications and instrumentation systems.

FAQ

What is the primary function of the DC1662A evaluation board?

The DC1662A evaluation board is designed exclusively to demonstrate and validate the performance of the LTC5585 RF quadrature demodulator IC. It enables engineers to characterize IIP2, DC offset, gain flatness, and I/Q imbalance across 30MHz–1GHz while supporting both manual (trim pot) and external-voltage calibration methods. The DC1662A itself contains no active logic or programmable elements - its role is purely analog signal path evaluation.

Does the DC1662A include the LTC5585 IC, and what is its package type?

Yes, the DC1662A includes one LTC5585IUF#PBF IC mounted in a 4mm × 4mm QFN-24 package (U1 on the schematic). This matches the exact ordering part listed in the bill of materials and is confirmed by the board's silkscreen and layout. The QFN package features exposed thermal pad and standard pinout per the LTC5585 datasheet.

How is DC offset and IIP2 calibrated on the DC1662A?

The DC1662A supports two distinct calibration workflows: Method 1 uses six onboard Bourns 3214X trim pots with JP1 shunted; Method 2 removes JP1 and applies external DC voltages (0.5V reference + variable IIP2/DCO signals) to five designated test points. Both methods directly interface with the LTC5585's internal calibration DACs, as specified in the Quick Start Guide and LTC5585 datasheet.

What RF test equipment connections are required to operate the DC1662A?

To operate the DC1662A, you need three RF signal sources (RF IN, LO IN, and optional termination), a spectrum analyzer with ≥30dB input attenuation, a 5V/250mA DC supply, a 1V/20mA auxiliary supply for VCTRL, and a DC voltmeter for VCC_SENSE monitoring. Figure 1 in the Quick Start Guide shows the full interconnect using Mini-Circuits combiners, pads, and DC blocks - all 50Ω matched.

Is the DC1662A compatible with other Linear Technology or Analog Devices demodulator evaluation boards?

No, the DC1662A is purpose-built for the LTC5585 and not mechanically or electrically compatible with other demodulator eval boards (e.g., DC1622A for LTC5582 or DC1712A for LTC5599). Its layout, balun (ANAREN BD0826J50200A00), test point locations, and calibration architecture are unique to the LTC5585's signal chain and pinout. Interchangeability is not supported.