Analog Devices Inc. 123773-HMC712LP3CE

Overview

HMC712LP3CE from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC voltage-variable attenuator operating from 5 to 26.5 GHz, delivering 28 dB analog attenuation range, +28 dBm input P1dB, and absorptive topology for broadband RF signal level control in microwave transceivers. It features dual shunt-type attenuation stages controlled by Vctrl1 and Vctrl2, housed in a 3×3 mm QFN package.

For engineers reviewing the HMC712LP3CE datasheet, HMC712LP3CE pinout, HMC712LP3CE application, or HMC712LP3CE equivalent, key selection criteria include its 5–26.5 GHz bandwidth, dual-voltage control architecture, RoHS-compliant 16-lead QFN package, and suitability for AGC loops and temperature-compensated gain blocks in point-to-point radio and VSAT systems.

Technical Context

The HMC712LP3CE implements two cascaded shunt-type GaAs MMIC attenuator stages with independent DC voltage control inputs (Vctrl1, Vctrl2), enabling precise 28 dB amplitude tuning across 5–26.5 GHz. Its absorptive topology ensures stable input/output match under all attenuation states.

Optimal linearity is achieved via sequential control: Vctrl1 is swept from −3 V to 0 V while Vctrl2 remains fixed at −3 V; then Vctrl2 is swept from −3 V to 0 V while Vctrl1 is held at 0 V. When Vctrl1 and Vctrl2 are tied together, full 28 dB range is retained with minor IP3 degradation.

Key Specifications

Pinout & Package

Package: 16-lead 3×3 mm QFN with exposed ground paddle (RoHS-compliant, MSL1, peak reflow 260 °C). Ground paddle must be soldered to PCB RF ground for thermal and RF performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage-variable attenuator applications.

Compared with HMC650LP3E and QM11036, the HMC712LP3CE uniquely delivers 28 dB range with sequenced dual-voltage control to sustain +32 dBm IP3 - making it the preferred choice for high-fidelity microwave AGC in demanding point-to-point and defense applications.

Availability

HMC712LP3CE is available at Aetrix Electronics and suitable for point-to-point radio, VSAT terminal, and military radar applications requiring stable component supply, full RoHS compliance, and guaranteed long-term availability through extended lifecycle management.

Supply support for HMC712LP3CE 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 RF signal chain solutions for communications, defense, and instrumentation markets.

The HMC712LP3CE belongs to Hittite's legacy GaAs MMIC voltage-variable attenuator product line, engineered specifically for broadband microwave systems demanding high linearity, wide dynamic range, and robust thermal performance in compact SMT packages.

FAQ

What is the recommended control voltage sequencing for optimal linearity in the HMC712LP3CE?

The HMC712LP3CE achieves best linearity by first sweeping Vctrl1 from −3 V to 0 V while holding Vctrl2 at −3 V, then sweeping Vctrl2 from −3 V to 0 V while fixing Vctrl1 at 0 V. This two-step sequence preserves +32 dBm input IP3 across the full 28 dB attenuation range. Deviating from this order degrades IP3 by up to 4 dB at 10 GHz. The HMC712LP3CE datasheet specifies this exact procedure in the "Electrical Specifications" section.

Can the HMC712LP3CE operate with Vctrl1 and Vctrl2 tied together?

Yes, the HMC712LP3CE supports single-control operation by connecting Vctrl1 and Vctrl2. This configuration retains the full 28 dB attenuation range but incurs a ~2–3 dB reduction in input IP3 compared to sequenced control. It simplifies bias circuitry in applications where moderate linearity suffices, such as basic gain leveling in test equipment. The HMC712LP3CE evaluation board (P/N 123773) demonstrates this configuration.

What is the thermal design requirement for continuous operation of the HMC712LP3CE?

The HMC712LP3CE has a channel-to-paddle thermal resistance of 66 °C/W and supports 1 W continuous power dissipation at 85 °C case temperature. To meet this, the exposed ground paddle must be fully soldered to a multilayer PCB ground plane with ≥6 thermal vias (0.3 mm diameter, spaced ≤1 mm apart). Without proper thermal management, junction temperature exceeds 150 °C at 85 °C ambient, violating the HMC712LP3CE absolute maximum rating.

Is the HMC712LP3CE pin-compatible with other Hittite LP3E-series attenuators?

No, the HMC712LP3CE is not pin-compatible with other LP3E-series devices such as HMC650LP3E or HMC647LP3E. While all share the 3×3 mm QFN footprint, pin functions differ: HMC712LP3CE uses dedicated Vctrl1/Vctrl2 inputs (pins 6 and 7), whereas HMC650LP3E consolidates control onto a single pin. PCB layout must be redesigned for each part. The HMC712LP3CE pinout is documented in its Application Circuit diagram on page 7 of the official datasheet.

Does the HMC712LP3CE require external DC blocking capacitors on RFIN and RFOUT?

Yes, the HMC712LP3CE has DC-coupled RFIN (pin 3) and RFOUT (pin 10), both matched to 50 Ω. External 100 pF blocking capacitors (0402 size) are mandatory if the connected RF line carries DC bias ≠ 0 V - for example, when interfacing with biased LNAs or PAs. Omitting them risks forward conduction through internal GaAs diodes and permanent damage. The HMC712LP3CE evaluation PCB (P/N 123773) includes C1 and C2 for this purpose.