Analog Devices Inc. 119394-HMC639ST89

Overview

The HMC639ST89 from Analog Devices (formerly Hittite Microwave) is a GaAs pHEMT high-linearity, low-noise wideband gain block amplifier operating from 0.2 to 4.0 GHz. It delivers +22 dBm P1dB output power, 13 dB small-signal gain, 2.3 dB noise figure, and +38 dBm output IP3 at +5 V supply, serving as a cascadable 50 Ω RF gain stage in cellular base stations and microwave radio front-ends.

For engineers reviewing the HMC639ST89 datasheet, HMC639ST89 pinout, HMC639ST89 application, or HMC639ST89 equivalent, this amplifier's internally matched 50 Ω I/Os, SOT89 package, temperature-stable gain (±0.02 dB/°C), and no-external-matching operation simplify RF board integration across wireless infrastructure and broadband IF sections.

Technical Context

This amplifier uses a GaAs pHEMT process with internal DC biasing and broadband 50 Ω impedance matching on both input and output. Its monolithic topology eliminates external matching components and supports stable operation from –40°C to +85°C with <±0.02 dB/°C gain variation and >12 dB input/output return loss.

Designed for single-supply +5 V operation, it draws 90–120 mA quiescent current and achieves 2.3 dB noise figure at 2.2 GHz while maintaining +38 dBm OIP3 - enabling high dynamic range in receiver LNA and transmitter pre-driver roles without cascaded filtering or tuning.

Key Specifications

Pinout & Package

Package: Industry-standard SOT-89 (3-lead variant with exposed thermal pad; pin 2 and 4 are GND, per outline drawing and pin descriptions). Thermal resistance (channel-to-lead) is 75.6 °C/W; bottom thermal pad must be soldered to PCB RF ground.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar wideband RF gain block applications.

Compared with QPL9547 and PSA4-5043+, the HMC639ST89 uniquely balances 0.2–4.0 GHz bandwidth, 2.3 dB NF, and +38 dBm OIP3 in a thermally robust SOT-89 package - making it optimal for infrastructure-grade applications demanding both wideband fidelity and high linearity.

Availability

HMC639ST89 is available at Aetrix Electronics and suitable for cellular base station receivers, WiMAX transmitters, microwave radio IF sections, and CATV node amplifiers requiring stable component supply, long-lifecycle support, and traceable sourcing.

Supply support for HMC639ST89 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 acquired Hittite Microwave in 2014 and integrates its high-frequency RF portfolio into precision analog and RF solutions for communications, defense, and instrumentation markets.

The HMC639ST89 belongs to Hittite's legacy wideband GaAs gain block family, engineered for infrastructure RF signal conditioning where low noise, high linearity, and ease of integration are critical.

FAQ

What is the operating temperature range for the HMC639ST89?

The HMC639ST89 operates reliably from –40°C to +85°C ambient temperature. Its gain variation is tightly controlled at ±0.02 dB/°C, and noise figure remains stable across this range - verified per electrical specifications at +25°C, +85°C, and –40°C test points. This makes the HMC639ST89 suitable for outdoor wireless infrastructure deployments where thermal cycling is expected.

Does the HMC639ST89 require external matching components?

No, the HMC639ST89 features fully internal 50 Ω matching on both input and output ports. The device only requires an external DC blocking capacitor on Pin 1 (RFIN) and proper RF grounding of Pins 2 and 4 plus the package bottom. No baluns, stubs, or LC networks are needed - enabling direct integration onto FR4, Rogers, or hybrid PCBs regardless of dielectric constant or thickness.

What is the absolute maximum RF input power rating for the HMC639ST89?

The absolute maximum RF input power for the HMC639ST89 is +15 dBm when operated at +5 V supply, as defined in the Absolute Maximum Ratings table. Exceeding this level risks permanent damage due to gate oxide stress or thermal runaway. For safe linear operation, input power should remain ≤ –10 dBm to avoid compression or distortion in LNA configurations.

How is DC bias applied to the HMC639ST89?

DC bias is applied through Pin 3 (RFOUT), which serves as both RF output and DC supply terminal. A bias tee or RF choke must be used to inject +5 V DC while passing RF signals. Pin 1 (RFIN) is DC-coupled but requires an external DC blocking capacitor. Pins 2 and 4 are ground terminals and must be soldered to the PCB ground plane along with the exposed thermal pad.

Is the HMC639ST89 RoHS-compliant?

The HMC639ST89 is not RoHS-compliant; it uses Sn/Pb lead finish and is rated MSL1 with a peak reflow temperature of 235°C. Its RoHS-compliant counterpart is the HMC639ST89E, which features 100% matte tin plating and 260°C reflow compatibility. Both share identical electrical performance and pinout, but material compliance differs per package marking and MSL specification.