Analog Devices Inc./Maxim Integrated MAX2473EUT

Overview

MAX2473EUT from Maxim Integrated is a single-output, wideband VCO buffer amplifier optimized for RF signal isolation and power-controlled distribution in frequency synthesis chains. It delivers adjustable output power from –10 dBm to –2 dBm with harmonic suppression below –25 dBc, reverse isolation of 49 dB at 900 MHz, and operates across 500–2500 MHz on a +2.7V to +5.5V supply - ideal for cellular transceiver local oscillator buffering.

For engineers reviewing the MAX2473EUT datasheet, MAX2473EUT pinout, MAX2473EUT application, or MAX2473EUT equivalent, key selection criteria include its bias-controlled output power range, SOT23-6 footprint compatibility, high input impedance (>250 Ω at 900 MHz), and suitability for low-power IF/RF oscillator distribution where reverse isolation and minimal loading are critical.

Technical Context

The MAX2473EUT implements a two-stage wideband architecture: a high-input-impedance common-emitter amplifier followed by a single open-collector output stage with external bias resistor (R_BIAS) control. Its internal 1.2 V reference enables precise current setting via R_BIAS (11 kΩ to 23 kΩ) to tune output power and gain across frequency.

Reverse isolation is maintained above 48 dB from 600 MHz to 2400 MHz, and transducer gain remains stable (6.4–9.9 dB) over temperature and frequency - achieved through reactive output matching and careful GND pin layout per RF design best practices. The device requires AC-coupled inputs and open-collector DC blocking at outputs.

Key Specifications

Pinout & Package

MAX2473EUT is housed in a 6-pin SOT23-6 package with exposed pad (not electrically connected), requiring tight RF grounding via both GND pins (Pins 2 and 5). Pin 1 is OUT, Pin 3 is BIAS, Pin 4 is IN, Pin 6 is V_CC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar VCO buffer amplifier applications.

Compared with MAX2472EUT-T, MAX2473EUT offers lower power consumption and output power tunability at the cost of single-output capability; versus QPL9057TR13, it provides superior VCO loading immunity and bias flexibility but demands external matching and layout attention to GND integrity.

Availability

MAX2473EUT is available at Aetrix Electronics and suitable for cellular transceivers, ISM-band wireless sensors, private mobile radios, and IF/RF oscillator distribution requiring stable component supply, full traceability, and long-term lifecycle support.

Supply support for MAX2473EUT 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) designs precision analog, mixed-signal, and RF ICs for communications, industrial, and consumer applications - emphasizing integration, power efficiency, and signal integrity.

The MAX2473EUT belongs to Maxim's VCO buffer amplifier product line, engineered specifically for high-isolation, low-power RF signal distribution in frequency synthesis subsystems - targeting cellular infrastructure, portable radios, and wireless sensor platforms.

FAQ

What is the recommended R_BIAS value to achieve –5 dBm output from the MAX2473EUT at 900 MHz?

The MAX2473EUT achieves approximately –5 dBm output power at 900 MHz with an R_BIAS value of 15 kΩ, as confirmed in the Typical Operating Characteristics (Figure MAX2472 toc13a). This resistor connects between Pin 3 (BIAS) and GND, and its value directly sets the output stage bias current. For production designs, verify output level with actual board layout and matching network, as parasitic effects may shift the exact power point by ±0.5 dB.

Can the MAX2473EUT be used with a 50 Ω VCO source without external input matching?

No - the MAX2473EUT features high input impedance (>250 Ω at 900 MHz), so direct connection to a 50 Ω VCO source causes significant mismatch and degraded reverse isolation. Per the Applications Information section, a shunt termination resistor (R_TERM) must be added such that R_TERM || Re[S₁₁] ≈ 50 Ω, along with a series DC-blocking capacitor. This ensures stable 50 Ω input matching and preserves the MAX2473EUT's specified 49 dB reverse isolation.

Does the MAX2473EUT require external output matching components, and if so, what are typical values?

Yes - the MAX2473EUT has open-collector output architecture and requires external reactive matching. At 900 MHz, typical values are a 12 nH choke (Coilcraft 0603HS-12NTJBC) from Pin 1 (OUT) to V_CC, and a 1 pF DC-blocking capacitor (Murata GRM39COG1R0B50V) in series to the load. Table 1 in the datasheet provides LMATCH and CMATCH values for 600, 900, 1900, and 2400 MHz - all verified for use with the MAX2473EUT under standard test conditions.

What is the maximum input power the MAX2473EUT can handle without damage or performance degradation?

The MAX2473EUT has an Absolute Maximum Rating of +10 dBm for continuous input power. However, for linear operation and guaranteed AC specifications (e.g., harmonic suppression, gain flatness), the datasheet specifies testing at –25 dBm input. Operation above –10 dBm risks compression, increased distortion, and potential reliability impact - especially at elevated temperatures. Always limit input to ≤ –10 dBm in production designs unless derated per thermal analysis.

How does the MAX2473EUT's reverse isolation compare across its operating frequency band?

The MAX2473EUT maintains ≥48 dB reverse isolation from 600 MHz to 2400 MHz, with peak performance of 49 dB at 900 MHz. Data sheet Figure MAX2472 toc15 shows reverse isolation vs. R_BIAS at 900 MHz, and scattering parameter tables confirm values of 48 dB at 600 MHz, 49 dB at 900 MHz, 43 dB at 1900 MHz, and 35 dB at 2400 MHz. This broadband isolation is critical for preventing VCO pulling in multi-load RF architectures using the MAX2473EUT.