Analog Devices Inc. 106975-HMC849LP4CE

Overview

HMC849LP4CE from Hittite Microwave Corporation is a GaAs pHEMT SPDT RF switch optimized for non-reflective signal routing in DC–6 GHz systems, delivering 60 dB isolation at 2 GHz, 0.8 dB insertion loss (DC–2 GHz), and +52 dBm input IP3. It operates with single positive control (0/+3V or 0/+5V), supports an "all off" state via EN pin, and targets cellular/WiMAX infrastructure front-ends.

For engineers reviewing the HMC849LP4CE datasheet, HMC849LP4CE pinout, HMC849LP4CE application, or HMC849LP4CE equivalent, key selection criteria include isolation vs. frequency, non-reflective termination behavior, thermal power handling up to +31 dBm P1dB, and compatibility with 4×4 mm QFN PCB layouts requiring grounded paddle and RF ground stitching.

Technical Context

The HMC849LP4CE implements a monolithic GaAs pHEMT architecture with integrated bias circuitry enabling single-supply, dual-voltage (3V/5V) digital control. Its non-reflective design terminates the off-path port into 50 Ω, minimizing system VSWR impact during switching - critical for TDD/FDD transceiver architectures.

Control logic uses two inputs (Vctl and EN) to select RFC→RF1, RFC→RF2, or all-off states; EN high forces both paths off regardless of Vctl. The device maintains stable RF performance across –40°C to +85°C with MSL1 reflow rating and Class 1A ESD protection.

Key Specifications

Pinout & Package

Package: 16-lead 4×4 mm QFN with exposed thermal paddle; RoHS-compliant, matte Sn finish, MSL1 rated (260 °C peak reflow). Ground leads (pins 4,6,7,8,13,14,15,16) and paddle must be soldered to PCB RF ground per Hittite land pattern guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SPDT RF switch applications.

Compared with QM11036 and SKY13372-374LF, the HMC849LP4CE uniquely balances 60 dB isolation, single-supply 0/+5V control, and dedicated EN pin - making it optimal for infrastructure-grade TDD systems requiring guaranteed off-state termination and thermal resilience.

Availability

HMC849LP4CE is available at Aetrix Electronics and suitable for cellular infrastructure, WiMAX fixed wireless access, and automotive telematics applications requiring stable component supply, long-term lifecycle support, and traceable RoHS-compliant sourcing.

Supply support for HMC849LP4CE 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-performance RFICs, MMICs, and microwave components for defense, communications, and instrumentation markets.

The HMC849LP4CE belongs to Hittite's high-isolation GaAs SPDT switch product line, engineered specifically for broadband infrastructure transceivers demanding non-reflective switching, thermal reliability, and simplified digital control.

FAQ

What is the maximum RF input power the HMC849LP4CE can handle continuously?

The HMC849LP4CE supports +31 dBm P1dB compression at 5 V supply, with thermal limits defined by its 1.144 W through-path dissipation rating and 56.8 °C/W thermal resistance. Under 85 °C ambient, continuous operation at +31 dBm requires adequate PCB copper area and ground paddle soldering per Hittite's land pattern. Derating applies above 85 °C.

Does the HMC849LP4CE require external 50 Ω termination resistors for the off-state path?

No. The HMC849LP4CE is a non-reflective switch: its internal architecture terminates the off-state RF port into 50 Ω, eliminating the need for external resistors. This preserves board space and avoids parasitic effects from discrete terminations - confirmed in the functional diagram and truth table of the official datasheet.

Can the HMC849LP4CE operate with only a 3 V supply, and how does that affect RF performance?

Yes, the HMC849LP4CE operates with 3 V supply, delivering +29 dBm P1dB and +52 dBm IP3 (typical). Insertion loss increases slightly (e.g., 0.9 dB vs. 0.8 dB at 2 GHz), and isolation remains ≥53 dB up to 2 GHz. Bias current drops to 0.8 mA, reducing system power consumption while maintaining full DC–6 GHz functionality.

What is the role of the EN pin on the HMC849LP4CE, and how does it interact with Vctl?

The EN pin on the HMC849LP4CE provides hardware-level override: when pulled high, it forces both RF paths into "off" state regardless of Vctl logic level. This enables fail-safe shutdown, TDD guard interval blanking, or system-level RF disable - a feature absent in most competing SPDT switches and explicitly documented in the truth table.

Is the HMC849LP4CE pin-compatible with other Hittite SPDT switches like the HMC849LP3E?

No. The HMC849LP4CE uses a 16-lead 4×4 mm QFN package, whereas the HMC849LP3E is an older 16-lead 3×3 mm QFN variant with different pinout and land pattern. Pin mapping, thermal pad configuration, and control voltage thresholds differ - direct replacement requires PCB redesign and layout verification per each device's outline drawing.