Analog Devices Inc./Maxim Integrated MAX2680AUT+

Overview

The MAX2680AUT+ from Maxim Integrated is a silicon-germanium (SiGe) double-balanced downconverter mixer designed for RF-to-IF signal translation in portable wireless systems. It operates with RF input from 400MHz to 2500MHz, delivers 11.6dB conversion gain at 900MHz, exhibits 6.3dB noise figure at 900MHz, draws 5.0mA supply current, and supports single +2.7V to +5.5V operation - enabling direct use with 3-cell NiCd or 1-cell Li-ion batteries in ISM-band radios.

For engineers reviewing the MAX2680AUT+ datasheet, MAX2680AUT+ pinout, MAX2680AUT+ application, or MAX2680AUT+ equivalent, key selection considerations include its 6-pin SOT23 package, low-power shutdown (<0.1μA), IIP3 of –6.9dBm at 2450MHz, and RF/LO/IF port impedance matching requirements across frequency bands.

Technical Context

The MAX2680AUT+ implements a Gilbert-cell-based double-balanced mixer architecture with single-ended RF, LO, and open-collector IF ports. Its on-chip bias cell enables active-low shutdown control, and it requires external DC-blocking capacitors on RFIN and LO, plus an RF choke (inductor) from IFOUT to VCC for proper biasing.

It operates over –40°C to +85°C, supports 10MHz–500MHz IF output, maintains LO input VSWR ≤1.5:1 across 400MHz–2500MHz, and achieves LO-to-IF isolation >22dB at 1880MHz - critical for minimizing local oscillator feedthrough in compact transceiver designs.

Key Specifications

Pinout & Package

MAX2680AUT+ is housed in a RoHS-compliant 6-pin SOT23 package (JEDEC MO-178AA), with exposed pad not electrically connected. Pin 1 is identified by a dot or beveled edge; top marking "AAAR" confirms MAX2680 variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX2681EUT+ and LT5526EMS#TRPBF, the MAX2680AUT+ offers the lowest power consumption (5.0mA) and best noise figure (6.3dB) among SiGe mixers in SOT23, making it optimal for battery-powered ISM-band receivers where sensitivity and runtime are prioritized over ultimate linearity.

Availability

MAX2680AUT+ is available at Aetrix Electronics and suitable for ISM-band radios, cellular handsets, IEEE 802.11 clients, and wireless local loop terminals requiring stable component supply, consistent parametric performance, and long-term manufacturability assurance.

Supply support for MAX2680AUT+ 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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and RF solutions for industrial, communications, and consumer markets.

The MAX2680AUT+ belongs to Maxim's SiGe downconverter mixer family, engineered specifically for low-voltage, low-noise, high-frequency signal translation in portable and battery-operated wireless equipment.

FAQ

What is the maximum RF input power rating for the MAX2680AUT+?

The MAX2680AUT+ specifies a maximum continuous RF input power of +10dBm into a 50Ω source, as defined in Absolute Maximum Ratings. Exceeding this may cause permanent damage. For reliable operation, typical RF input is –25dBm per tone during two-tone IIP3 testing; system-level design should include front-end attenuation or limiting to stay within safe margins under worst-case signal conditions.

Does the MAX2680AUT+ require external matching components on all ports?

Yes, the MAX2680AUT+ requires external matching networks on RFIN, LO, and IFOUT. RFIN needs Z1/Z2/Z3 per Table 2 (e.g., 86nH + 270pF at 400MHz); LO requires only a DC-blocking capacitor; IFOUT demands an RF choke to VCC plus L1/C2/R1 per Table 4 (e.g., 330nH + 15pF at 70MHz). These are mandatory for achieving specified gain, NF, and IIP3.

Can the MAX2680AUT+ operate with a 1.8V supply?

No - the MAX2680AUT+ has a minimum supply voltage of +2.7V per Absolute Maximum Ratings and Electrical Characteristics tables. Operation below 2.7V is not characterized, guaranteed, or supported. For 1.8V systems, consider alternative mixers such as the ADL5801 or evaluate level-shifting/shutdown control interfacing, but VCC must remain ≥2.7V.

What is the function of the SHDN pin, and how should it be driven?

The SHDN pin is an active-low digital control that disables internal bias circuits. Drive it ≤0.5V (typically GND) to achieve <0.1μA shutdown current; drive ≥2.0V (or tie directly to VCC) for normal operation. A 100Ω series resistor and 1000pF bypass capacitor to GND are recommended to suppress RF noise coupling into the shutdown path.

Is the MAX2680AUT+ pin-compatible with MAX2681EUT+ or MAX2682EUT+?

Yes - all three variants (MAX2680AUT+, MAX2681EUT+, MAX2682EUT+) share identical 6-pin SOT23 pinout, package dimensions, and footprint. They differ only in internal biasing, resulting in distinct IIP3, gain, noise figure, and supply current. No PCB changes are needed when upgrading between them, though matching networks and supply filtering may require optimization.