Analog Devices Inc. 107384-HMC492LP3

Overview

HMC492LP3 from Analog Devices (formerly Hittite Microwave) is a GaAs HBT MMIC divide-by-2 static frequency divider operating from DC (square-wave input) to 18 GHz with -4 dBm typical output power, -150 dBc/Hz SSB phase noise at 100 kHz offset, and single +5V supply operation - used in high-frequency PLL prescalers for point-to-point radios and test equipment.

For engineers reviewing the HMC492LP3 datasheet, HMC492LP3 pinout, HMC492LP3 application, or HMC492LP3 equivalent, key selection criteria include its 18 GHz max input frequency, differential RF input capability, 3×3 mm QFN package with exposed ground paddle, and compatibility with DC-coupled square-wave or AC-coupled sine-wave inputs across military, fiber optic, and VSAT systems.

Technical Context

The HMC492LP3 implements a static CML-based divide-by-2 architecture using InGaP GaAs HBT technology, enabling deterministic division without lock acquisition delay. It supports both single-ended (pin 2 active, pin 3 AC-grounded) and true differential RF input (pins 2 and 3 driven 180° out-of-phase), with dual 5V supply pins (14 and 15) and two complementary 18 GHz-capable RF outputs (pins 10 and 11).

Its operation down to DC requires square-wave excitation; for sine-wave inputs, minimum frequency is 200 MHz (typical). The device delivers stable -4 dBm output across 0.5–18 GHz while maintaining ultra-low additive phase noise and >60 dB reverse isolation between output ports - critical for low-jitter clock distribution in wideband synthesizers.

Key Specifications

Pinout & Package

Package: 3×3 mm, 16-lead leadless QFN with exposed ground paddle (MSL1, Sn/Pb finish); requires soldering of all ground leads and backside slug to PCB RF ground per Hittite land pattern guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC492LP3, HMC363LP4E offers /4 division and lower voltage but sacrifices 5 GHz bandwidth and phase noise performance, while HMC735LP3 extends usable frequency to 22 GHz with marginally higher phase noise - making it a direct upgrade path for Ka-band systems requiring identical form factor and supply.

Availability

HMC492LP3 is available at Aetrix Electronics and suitable for point-to-point radios, fiber optic transceivers, and military radar systems requiring stable component supply, consistent RF performance across temperature, and long-term obsolescence management.

Supply support for HMC492LP3 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 maintains its high-frequency RF portfolio, delivering precision analog, RF, and microwave components for communications, defense, and instrumentation markets.

The HMC492LP3 belongs to Hittite's legacy GaAs HBT MMIC frequency divider family, engineered specifically for ultra-wideband, low-phase-noise prescaling in microwave PLLs and high-speed serial timing recovery circuits.

FAQ

What input signal types does the HMC492LP3 support?

The HMC492LP3 accepts both square-wave inputs (down to DC) and sine-wave inputs (minimum 200 MHz typical). For sine-wave operation, external DC blocking capacitors are required on pins 2 and 3. Differential drive (180° out-of-phase signals on pins 2 and 3) improves common-mode rejection and reduces even-order harmonics. The HMC492LP3 does not require external biasing networks due to its integrated HBT biasing scheme.

Does the HMC492LP3 require external power supply filtering?

Yes - the HMC492LP3 requires local decoupling on both Vcc1 (pin 14) and Vcc2 (pin 15). Per the evaluation board design, each supply pin needs a 100 pF ceramic capacitor (0402) plus a 2.2 µF tantalum capacitor. Insufficient decoupling causes gain ripple, increased phase noise, and potential oscillation above 10 GHz. The HMC492LP3 datasheet specifies 78 mA total supply current at +5 V, confirming the need for low-ESR, high-frequency bypassing.

Can the HMC492LP3 be used in differential output mode?

Yes - pins 10 and 11 provide true complementary /2 outputs with 180° phase relationship and matched amplitude. This enables direct interface to differential CML or LVDS receivers without external baluns. The HMC492LP3 achieves >60 dB reverse isolation between these outputs, minimizing crosstalk in high-density RF layouts. For single-ended use, either output may be terminated while the other drives the load.

What is the recommended PCB grounding method for the HMC492LP3?

The HMC492LP3 requires soldering its exposed ground paddle to a solid top-layer RF ground plane using ≥6 thermal vias connected to inner ground layers. All ground leads (pins 1, 4–9, 12, 13, 16) must also connect to this plane. Per Hittite Application Note, failure to fully ground the paddle increases thermal resistance beyond 84 °C/W and degrades SSB phase noise by up to 4 dB. The HMC492LP3 evaluation board (107384) uses Rogers 4350 substrate to maintain controlled 50 Ω impedance.

Is the HMC492LP3 RoHS-compliant?

The HMC492LP3 uses Sn/Pb lead finish and is not RoHS-compliant; the RoHS-compliant variant is HMC492LP3E (100% matte tin, MSL1, 260 °C peak reflow). Both share identical electrical specifications and pinout. The HMC492LP3 remains available for legacy industrial and military programs where Sn/Pb assembly is permitted. Form, fit, and function are identical between HMC492LP3 and HMC492LP3E - only the finish and reflow profile differ.