Analog Devices Inc. 105706-HMC429LP4

Overview

105706-HMC429LP4 from Analog Devices (formerly Hittite Microwave) is a GaAs InGaP HBT MMIC voltage-controlled oscillator with integrated buffer amplifier, operating from 4.45 to 5.0 GHz. It delivers +4.0 dBm RF output at 3.0 V / 30 mA, achieves −105 dBc/Hz phase noise at 100 kHz offset, and requires no external resonator. It serves as a low-noise local oscillator in 802.11a/WLAN and microwave radio transceivers.

For engineers reviewing the 105706-HMC429LP4 datasheet, 105706-HMC429LP4 pinout, 105706-HMC429LP4 application, or 105706-HMC429LP4 equivalent, key selection criteria include its monolithic VCO architecture, 4.45–5.0 GHz tuning range, 3V single-supply operation, QFN-16 package footprint, and −105 dBc/Hz phase noise performance across temperature and vibration.

Technical Context

The 105706-HMC429LP4 integrates a negative-resistance oscillator core, varactor tuning diode, and buffer amplifier on a single GaAs die, eliminating discrete resonator components and enabling stable frequency generation over −40°C to +85°C. Its monolithic construction ensures consistent phase noise and pulling/pushing performance under shock, vibration, and process variation.

Tuning is achieved via a 0–10 V control voltage applied to VTUNE (Pin 22), delivering 14 MHz/V pushing sensitivity and <10 MHz peak-to-peak pulling into 2.0:1 VSWR. The RF output (Pin 16) is AC-coupled, and the exposed paddle must be RF/DC grounded per RF layout best practices.

Key Specifications

Pinout & Package

The 105706-HMC429LP4 is housed in a leadless 4×4 mm QFN package (MSL1, Sn/Pb finish) with an exposed metal paddle requiring RF/DC grounding. All ground pins (15, 17–19, 21, 23–24) and the paddle must connect directly to the PCB ground plane using ≥6 thermal vias.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC429LP4E and HMC513LP5, the 105706-HMC429LP4 offers optimal balance of size, power efficiency, and UNII-3 band coverage-making it ideal for space-constrained 802.11a modules where 4.45–5.0 GHz range and 30 mA consumption are primary constraints.

Availability

105706-HMC429LP4 is available at Aetrix Electronics and suitable for 802.11a/WLAN infrastructure, VSAT outdoor units, and portable RF test equipment requiring stable component supply, consistent lot-to-lot RF performance, and long-term obsolescence management.

Supply support for 105706-HMC429LP4 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 continues to manufacture and support its high-frequency RF portfolio, including MMIC VCOs, PLOs, and microwave ICs for defense, communications, and instrumentation.

The 105706-HMC429LP4 belongs to Hittite's legacy MMIC VCO family designed for low-phase-noise, surface-mount local oscillator generation in 4–6 GHz wireless and aerospace systems-prioritizing monolithic integration and ruggedized RF performance.

FAQ

What is the recommended PCB layout for the 105706-HMC429LP4?

Use RF-aware layout: 50 Ω microstrip routing to Pin 16 (RFOUT), ground all GND pins (15, 17–19, 21, 23–24) and the exposed paddle with ≥6 thermal vias to inner/outer ground planes, place 4.7 μF tantalum + 10,000 pF ceramic capacitors near Pin 20 (Vcc), and isolate VTUNE (Pin 22) from noisy digital traces. The 105706-HMC429LP4 evaluation board (P/N 105667) uses Rogers 4350 substrate and is available upon request.

Does the 105706-HMC429LP4 require external tuning components?

No-the 105706-HMC429LP4 integrates all resonator elements, varactor diodes, and buffer amplifier on a single GaAs die. No external inductors, capacitors, or resonators are needed. Only external DC blocking (e.g., 100 pF) at RFOUT and decoupling at Vcc are required. This monolithic design eliminates tuning drift and reduces sensitivity to PCB parasitics, making the 105706-HMC429LP4 suitable for high-reliability 5 GHz systems.

What is the absolute maximum rating for VTUNE on the 105706-HMC429LP4?

The absolute maximum VTUNE voltage for the 105706-HMC429LP4 is +11 V, per the Absolute Maximum Ratings table. Operation above this level risks permanent damage to the internal varactor diode. For reliable performance, keep VTUNE within 0–10 V during normal operation. The 105706-HMC429LP4 exhibits 14 MHz/V pushing sensitivity at VTUNE = +5 V, so precise control voltage regulation is essential for stable frequency synthesis.

How does the 105706-HMC429LP4 perform under temperature variation?

The 105706-HMC429LP4 maintains −105 dBc/Hz phase noise at 100 kHz offset across −40°C to +85°C, with frequency drift of only 0.4 MHz/°C. Its monolithic GaAs HBT structure minimizes thermal coefficient mismatches between oscillator core and tuning elements. Pulling remains ≤10 MHz pp into 2.0:1 VSWR across temperature, ensuring robust operation in outdoor VSAT and military radios where ambient conditions vary widely. This thermal stability is intrinsic to the 105706-HMC429LP4 design.

Can the 105706-HMC429LP4 be used in a PLL configuration?

Yes-the 105706-HMC429LP4 is commonly used as the VCO in integer-N and fractional-N PLL synthesizers for 5 GHz applications. Its 0–10 V VTUNE range interfaces directly with standard charge-pump PLL ICs, and its 14 MHz/V pushing sensitivity allows predictable loop filter design. Phase noise performance and low supply current make the 105706-HMC429LP4 well-suited for closed-loop frequency synthesis in WLAN APs and test equipment where spectral purity and power efficiency are critical.