Analog Devices Inc./Maxim Integrated MAX2684EUE

Overview

The MAX2684EUE from Maxim Integrated is a super-high-performance, double-balanced downconverter mixer optimized for 3.4–3.8GHz RF input and 800–1000MHz IF output in digital microwave radio (DMR) and wireless local loop (WLL) systems. It features +1dB typical conversion gain, +8 to +12dBm programmable IIP3, low-side LO injection only, and logic-enabled internal LO frequency doubler with integrated LO filtering.

For engineers reviewing the MAX2684EUE datasheet, MAX2684EUE pinout, MAX2684EUE application, or MAX2684EUE equivalent, this device is selected for high-linearity, wideband IF interface requirements in 3.5GHz point-to-point microwave receivers where LO harmonics suppression and bias-adjustable performance trade-offs are critical.

Technical Context

The MAX2684EUE implements a Gilbert-cell double-balanced architecture with single-ended RF and LO inputs and differential open-collector IF outputs. Its internal LO frequency doubler (enabled via ENX2 = GND) accepts half-frequency LO at LOX2 (1.2–1.45GHz), while disabling it (ENX2 = VCC) routes full-frequency LO directly to LOX1 (2.4–2.9GHz).

Externally adjustable bias is set by a single resistor (RBIAS) from BIAS to GND, enabling real-time optimization of supply current (55–66mA) versus linearity (IIP3: +8 to +12dBm). The device operates from +2.7V to +5.5V and integrates an on-chip LO bandpass filter to suppress harmonics and spurious mixing products.

Key Specifications

Pinout & Package

MAX2684EUE is housed in a 16-pin TSSOP-EP package with an exposed thermal paddle soldered to the PCB ground plane for optimal RF performance and thermal dissipation at 3.5GHz.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar downconverter mixer applications.

Compared with HMC774ALC3 and LT5560EDD, the MAX2684EUE uniquely balances 3.5GHz RF optimization, programmable linearity, integrated LO doubling, and single-supply operation in a compact TSSOP-EP-making it the targeted solution for production-grade 3.5GHz DMR/WLL receivers.

Availability

MAX2684EUE is available at Aetrix Electronics and suitable for wireless local loop (WLL), digital microwave radio (DMR), and 5G fixed wireless access (FWA) systems requiring stable component supply, consistent RF performance across temperature, and long-term obsolescence management.

Supply support for MAX2684EUE 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

Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and RF solutions for communications, industrial, and automotive markets.

The MAX2683/MAX2684 product line was designed specifically for high-reliability, low-cost downconversion in 3.4–3.8GHz wireless infrastructure equipment-emphasizing integration, thermal efficiency, and ease of RF layout.

FAQ

What is the primary RF and IF frequency range supported by the MAX2684EUE?

The MAX2684EUE supports an RF input frequency range of 3.4GHz to 3.8GHz and is optimized for IF output frequencies between 800MHz and 1000MHz. This makes it ideal for high-IF architectures in digital microwave radio systems where image rejection and filter complexity are critical concerns. The MAX2684EUE achieves best performance within this specific IF band, unlike the MAX2683EUE which targets 100–400MHz.

How does the ENX2 pin control LO frequency doubling in the MAX2684EUE?

The ENX2 pin on the MAX2684EUE is a logic-level control that selects LO path routing: driving ENX2 low enables the internal LO frequency doubler, directing the external LO signal to LOX2 (1.2–1.45GHz); driving ENX2 high disables the doubler and routes the full-frequency LO to LOX1 (2.4–2.9GHz). This feature allows system designers to choose between lower-frequency LO synthesis (reducing phase noise and VCO complexity) or lower supply current (15mA reduction when disabled).

Can the MAX2684EUE be used with high-side LO injection?

No, the MAX2684EUE supports low-side LO injection only, as confirmed in its functional description and electrical specifications. Unlike the MAX2683EUE-which supports both high-side and low-side LO injection-the MAX2684EUE is specifically optimized for low-side configuration in the 800–1000MHz IF range. Attempting high-side injection would result in degraded conversion gain, increased LO leakage, and out-of-spec IIP3 performance.

What is the role of the BIAS pin and how does RBIAS affect MAX2684EUE performance?

The BIAS pin on the MAX2684EUE connects to ground through an external resistor (RBIAS) to set operating point: decreasing RBIAS (e.g., 820Ω) increases supply current (up to 66mA) and improves IIP3 (+12dBm), while increasing RBIAS (e.g., 2kΩ) reduces current (to ~55mA) and degrades IIP3 (+8dBm). This single-resistor adjustment enables real-time trade-off between linearity and power consumption without changing layout or supply rails-critical for field-deployed WLL base stations.

Is the MAX2684EUE pin-compatible with the MAX2683EUE?

Yes, the MAX2684EUE is pin-compatible with the MAX2683EUE in the same 16-pin TSSOP-EP package, sharing identical pinout, supply requirements, and control interface. However, their internal optimizations differ: MAX2684EUE targets 800–1000MHz IF with low-side LO only, while MAX2683EUE targets 100–400MHz IF with dual-mode LO injection. System-level validation is required when substituting, especially regarding IF matching network and LO source configuration.