Analog Devices Inc. DC2391A

Overview

DC2391A from Analog Devices (formerly Linear Technology) is an evaluation board for the LTC5589 direct-conversion I/Q modulator, designed to accelerate RF transmitter development in 700MHz–6GHz wireless systems. It supports SPI-controlled gain/phase calibration, analog VCTRL-based fast power control, and delivers –50dBc side-band suppression at 1.8GHz with 19dBm OIP3 and –157dBm/Hz noise floor.

For engineers reviewing the DC2391A datasheet, DC2391A pinout, DC2391A application, or DC2391A equivalent, this board enables rapid characterization of LO feedthrough nulling, temperature-compensated gain stability, and wideband SDR transmitter linearity across 2.45GHz/5.8GHz ISM bands and LTE/WiMAX frequency plans.

Technical Context

The DC2391A implements the full reference design for the LTC5589, including matched 50Ω baseband I/Q input networks, integrated LC matching on LO and RF ports covering 700MHz–6GHz, and on-board thermometer/diode for closed-loop gain-temperature compensation. It routes all 24 QFN pins-including SPI (CSB/SCLK/SDI/SDO), EN, VCTRL, TEMP, and differential BBPI/BBMI/BBPQ/BBMQ-to accessible test points and SMA connectors.

It supports both sine-wave and square-wave LO drive, provides dual-mode gain control (digital SPI-adjustable 19dB range in 1dB steps + analog VCTRL 0.9V–3.3V), and enables side-band suppressed upconversion via factory-trimmed I/Q phase/gain imbalance correction registers-verified per Figure 12 test circuit in the LTC5589 datasheet.

Key Specifications

Availability

DC2391A is available at Aetrix Electronics and suitable for software-defined radio prototyping, battery-powered transmitter validation, and military comms RF front-end development requiring stable component supply and traceable evaluation hardware.

Supply support for DC2391A 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 leader in high-performance analog, mixed-signal, and RF ICs, formed through the acquisition of Linear Technology in 2017.

The DC2391A belongs to ADI's QuikEval™ evaluation platform family, engineered specifically to de-risk RF transmitter design by providing fully characterized, production-ready reference layouts for high-frequency direct-conversion modulators like the LTC5589.

FAQ

What is the primary function of the DC2391A evaluation board?

The DC2391A evaluation board is a fully assembled and tested platform for the LTC5589 direct-conversion I/Q modulator. It enables engineers to evaluate RF performance-including side-band suppression, LO feedthrough, output IP3, and noise floor-across the 700MHz–6GHz band without custom PCB design. The DC2391A includes all supporting circuitry per the LTC5589 datasheet Figure 12 reference design.

Does the DC2391A support both AC- and DC-coupled baseband inputs?

Yes, the DC2391A supports both AC- and DC-coupled baseband inputs as specified for the LTC5589. Its onboard interface preserves the 1.4V common-mode voltage requirement for BBPI/BBMI/BBPQ/BBMQ, and includes configurable coupling capacitors and bias networks to accommodate either configuration during DC2391A testing.

Can the DC2391A be used with square-wave local oscillator signals?

Yes, the DC2391A is designed to support both sine-wave and square-wave LO drive per the LTC5589 specification. Its LO port includes the recommended fixed LC matching network optimized for 700MHz–6GHz operation, enabling robust performance with digital LO sources-verified in the DC2391A user guide and LTC5589 datasheet Section "LO Port".

How does the DC2391A implement temperature compensation for the LTC5589?

The DC2391A routes the LTC5589's TEMP pin and on-chip diode to accessible test points, allowing external monitoring and closed-loop gain adjustment. It supports both the internal thermometer (for coarse compensation) and precision diode-based temperature measurement (for fine calibration), as documented in the LTC5589 Electrical Characteristics table and DC2391A schematic.

Is the DC2391A compatible with standard SPI controllers and signal generators?

Yes, the DC2391A features industry-standard 4-wire SPI (CSB, SCLK, SDI, SDO) with 20MHz maximum clock rate and TTL-compatible logic levels (VIH = 1.1V min, VIL = 0.2V max). Its baseband and LO SMA inputs accept standard RF signal generator outputs, and its RF output is directly measurable with spectrum analyzers-fully validated in the DC2391A user documentation.