Analog Devices Inc. HMC787LC3B

Overview

HMC787LC3B from Hittite Microwave Corporation is a GaAs MMIC double-balanced mixer designed for RF/LO frequency translation between 3–10 GHz and IF bandwidth DC–4 GHz. It delivers 9 dB typical conversion loss, 55 dB LO-to-RF isolation, and operates with +17 dBm LO drive-enabling upconversion or downconversion in microwave radios and test equipment.

For engineers reviewing the HMC787LC3B datasheet, HMC787LC3B pinout, HMC787LC3B application, or HMC787LC3B equivalent, key selection criteria include its passive balun-based topology, no-external-matching requirement, 12-lead 3×3 mm ceramic SMT package, and suitability for WiMAX infrastructure and military end-use where high isolation and wide IF bandwidth are critical.

Technical Context

This GaAs MESFET-based fundamental mixer uses a passive double-balanced topology with integrated baluns to achieve high LO-to-RF (55 dB) and LO-to-IF (35–42 dB) isolation across 3–10 GHz. Its DC-coupled RF, LO, and IF ports eliminate external bias tees while maintaining 50 Ω impedance matching.

The device requires no external matching components and supports both upconverter and downconverter configurations. Performance is specified at +17 dBm LO drive and 100 MHz IF, with input-referred IP3 of 23 dBm and P1dB of 15 dBm-indicating robust linearity for medium-power microwave signal chains.

Key Specifications

Pinout & Package

12-lead leadless ceramic SMT package (alumina body, gold-over-nickel plating, MSL3), 3×3 mm footprint with exposed ground paddle requiring solder connection to PCB RF ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar double-balanced mixer applications.

Compared with HMC787LC3B, HMC1048LP3E extends usable RF range by 8 GHz but sacrifices 7 dB LO-to-RF isolation and adds 1.5 dB conversion loss; QPC7350 offers lower loss in a narrower band and larger footprint, making HMC787LC3B optimal for C/X-band systems prioritizing isolation, compactness, and DC–4 GHz IF flexibility.

Availability

HMC787LC3B is available at Aetrix Electronics and suitable for WiMAX infrastructure, microwave radio, and military end-use requiring stable component supply, RoHS-compliant packaging, and proven performance in high-isolation RF signal chains.

Supply support for HMC787LC3B 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

Hittite Microwave Corporation, acquired by Analog Devices in 2014, specialized in high-frequency RF ICs including mixers, amplifiers, and synthesizers for defense, communications, and test equipment markets.

The HMC787LC3B belongs to Hittite's GaAs MMIC fundamental mixer product line, engineered for broadband, high-isolation frequency translation in microwave infrastructure where passive balun performance and SMT manufacturability are essential.

FAQ

What is the recommended LO drive level for optimal performance of the HMC787LC3B?

The HMC787LC3B is characterized and optimized for +17 dBm LO drive, delivering 9 dB typical conversion loss, 55 dB LO-to-RF isolation, and 23 dBm input IP3 at this level. Operating below +15 dBm increases conversion loss; above +19 dBm risks compression and accelerated degradation. The HMC787LC3B datasheet specifies all key parameters at +17 dBm, making it the design center for repeatable RF system performance.

Can the HMC787LC3B be used for zero-IF (direct-conversion) receiver applications?

Yes, the HMC787LC3B supports zero-IF operation due to its DC–4 GHz IF bandwidth and DC-coupled IF port. When used in direct-conversion receivers, the IF output can be connected directly to baseband amplifiers or ADCs without AC coupling. However, the IF port must not source or sink more than ±8 mA to avoid non-function or damage-this constraint must be verified in the baseband interface design for the HMC787LC3B.

Does the HMC787LC3B require external matching components for RF, LO, or IF ports?

No, the HMC787LC3B requires no external matching components-the RF, LO, and IF ports are internally matched to 50 Ω across 3–10 GHz (RF/LO) and DC–4 GHz (IF). This eliminates discrete baluns, transformers, or tuning stubs, simplifying layout and improving repeatability. The HMC787LC3B achieves this through monolithic GaAs MESFET balun integration, confirmed in its functional diagram and evaluation board documentation.

What is the thermal management requirement for the HMC787LC3B in continuous operation?

The HMC787LC3B features an exposed ground paddle with 87.7 °C/W thermal resistance (channel-to-ground). For continuous operation at max rated dissipation (0.74 W at 85 °C), the PCB must provide low-impedance thermal conduction via multiple vias to inner/outer ground planes. The HMC787LC3B package marking and outline drawing specify that the paddle must be soldered to RF ground-failure to do so degrades isolation, conversion loss, and thermal reliability.

Is the HMC787LC3B pin-compatible with other Hittite mixer variants such as HMC787LC3?

The HMC787LC3B is not pin-compatible with earlier HMC787LC3 revisions-the "B" suffix denotes a qualified revision with updated process control and screening, but identical pinout, package dimensions, and electrical specifications. All 12 pins (including N/C pins 10–12) retain identical functions and layout per the HMC787LC3B pin descriptions document. Thus, HMC787LC3B serves as a drop-in replacement for HMC787LC3 in existing designs.