Analog Devices Inc. 105706-HMC390LP4

Overview

105706-HMC390LP4 from Analog Devices (formerly Hittite Microwave) is a GaAs InGaP HBT monolithic voltage-controlled oscillator with integrated buffer amplifier, operating from 3.55 to 3.9 GHz. It delivers +4.7 dBm RF output power at 3 V/42 mA, achieves −112 dBc/Hz phase noise at 100 kHz offset, and requires no external resonator. It serves as a low-noise local oscillator in microwave radio transceivers.

For engineers reviewing the 105706-HMC390LP4 datasheet, 105706-HMC390LP4 pinout, 105706-HMC390LP4 application, or 105706-HMC390LP4 equivalent, key selection criteria include its 3.55–3.9 GHz tuning range, −112 dBc/Hz phase noise at 100 kHz, 3 V single-supply operation, QFN-16 package footprint, and ±3.3 MHz pulling tolerance into 2.0:1 VSWR.

Technical Context

The 105706-HMC390LP4 integrates a negative-resistance oscillator core, varactor tuning diode, and buffer amplifier on a single GaAs die, eliminating discrete resonator components and reducing layout sensitivity. Its monolithic architecture ensures stable phase noise performance across −40°C to +85°C and under mechanical shock/vibration.

It features a 0–10 V tuning voltage range with 0.4 MHz/°C frequency drift rate and −5 MHz/V pushing sensitivity at Vtune = +5 V. The RF output is AC-coupled, and the exposed paddle must be RF/DC grounded per RF PCB design best practices.

Key Specifications

Pinout & Package

The 105706-HMC390LP4 is housed in a leadless 4 × 4 mm QFN package (16-pin, MSL1, Sn/Pb finish) with an exposed metal paddle requiring RF/DC grounding. Pin 15 (GND), pins 1–14/17–19/21/23–24 (N/C), pin 16 (RFOUT), pin 20 (Vcc), and pin 22 (VTUNE) define the functional interface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC390LP4E, the 105706-HMC390LP4 offers Sn/Pb solder compatibility and lower reflow temperature (235°C), while ADRF6850 provides digital programmability at the cost of higher current draw and larger PCB area-making 105706-HMC390LP4 optimal for analog-tuned, space-constrained microwave radios.

Availability

105706-HMC390LP4 is available at Aetrix Electronics and suitable for wireless local loop infrastructure, VSAT terminals, and microwave point-to-point radio systems requiring stable component supply, consistent RF performance, and long-term obsolescence mitigation.

Supply support for 105706-HMC390LP4 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. is a global semiconductor leader specializing in high-performance analog, mixed-signal, and RF technologies for precision signal processing and connectivity.

The 105706-HMC390LP4 belongs to Analog Devices' legacy Hittite Microwave VCO product line, engineered for microwave communication systems demanding low phase noise, wide tuning range, and robust environmental performance.

FAQ

What is the operating temperature range for the 105706-HMC390LP4?

The 105706-HMC390LP4 operates reliably from −40°C to +85°C. Its monolithic GaAs structure ensures stable phase noise and frequency accuracy across this full industrial temperature range, with a measured frequency drift rate of only 0.4 MHz/°C. This makes the 105706-HMC390LP4 suitable for outdoor wireless infrastructure and military field-deployed equipment where ambient conditions vary widely.

Does the 105706-HMC390LP4 require external tuning components?

No, the 105706-HMC390LP4 does not require external resonators, inductors, or capacitors for basic VCO operation. Its fully integrated GaAs die includes the oscillator core, varactor diode, and buffer amplifier. Only external DC blocking on RFOUT and local decoupling on Vcc (4.7 µF + 10,000 pF) are required per the evaluation board design-no tuning network is needed for 3.55–3.9 GHz coverage.

What is the recommended PCB grounding strategy for the 105706-HMC390LP4?

The 105706-HMC390LP4 requires direct connection of its exposed metal paddle and pin 15 (GND) to a solid RF ground plane using multiple via holes. Per Hittite Application Note guidance, the ground leads and paddle must be soldered to PCB ground without thermal relief. Signal traces should maintain 50 Ω impedance, and the ground plane must be uninterrupted beneath the device to minimize inductance and ensure phase noise integrity.

How does the 105706-HMC390LP4 handle load impedance variations?

Load impedance variations are mitigated by the 105706-HMC390LP4's integrated buffer amplifier and specified pulling tolerance of ±3.3 MHz peak-to-peak into a 2.0:1 VSWR. This means that even with moderate antenna mismatch or filter insertion loss variation, the output frequency remains within acceptable limits for microwave radio timing budgets-eliminating need for isolators in many compact transceiver designs.

Can the 105706-HMC390LP4 be used with a 5 V supply?

No-the 105706-HMC390LP4 is rated for absolute maximum Vcc of +3.5 V and is characterized for optimal performance at +3.0 V. Operating above 3.5 V risks permanent damage. Supply current increases to 47 mA at 3.25 V and drops to 35 mA at 2.75 V, but phase noise and output power degrade outside the 3.0 V nominal condition. Always use a regulated 3.0 V supply with appropriate decoupling for the 105706-HMC390LP4.