Analog Devices Inc. HMC849LP4CE

Overview

HMC849LP4CE from Hittite Microwave Corporation is a GaAs pHEMT SPDT RF switch optimized for DC–6 GHz non-reflective signal routing in cellular/WiMAX/4G infrastructure. It delivers 60 dB isolation, 0.8 dB insertion loss (DC–2 GHz), +52 dBm input IP3, and +31 dBm P1dB at +5 V, operating with single positive 0/+3V or 0/+5V control logic.

For engineers reviewing the HMC849LP4CE datasheet, HMC849LP4CE pinout, HMC849LP4CE application, or HMC849LP4CE equivalent, key selection criteria include high-isolation RF path switching, low-loss broadband performance up to 6 GHz, non-reflective off-state behavior, and compatibility with +3V/+5V digital control interfaces in compact 4×4 mm QFN packages.

Technical Context

The HMC849LP4CE implements a monolithic GaAs pHEMT architecture with integrated bias circuitry enabling single-supply operation (Vdd = +3V to +5V) and dual-control inputs (Vctl and EN). Its non-reflective design terminates unused RF paths to 50 Ω, eliminating signal reflections during state transitions.

It supports three functional states via truth table logic: RFC→RF1 (EN=LOW, Vctl=HIGH), RFC→RF2 (EN=LOW, Vctl=LOW), and "All Off" (EN=HIGH). Switching speed is characterized at tRISE/tFALL = 80 ns and tON/tOFF = 600 ns over DC–4 GHz under 50 Ω system conditions.

Key Specifications

Pinout & Package

16-lead 4×4 mm leadless QFN package with exposed ground paddle; RoHS-compliant matte tin finish, MSL1 rating, and required solder connection of all ground leads and bottom paddle to PCB RF ground per Hittite Application Note land pattern guidance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with QM11036 and HMC646LP4E, the HMC849LP4CE provides superior isolation and P1dB within its 6 GHz band, making it optimal for high-performance transmit-path switching where signal integrity and power handling are primary constraints.

Availability

HMC849LP4CE is available at Aetrix Electronics and suitable for cellular infrastructure, WiMAX base stations, and automotive telematics requiring stable component supply with guaranteed long-term availability and traceable 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, now part of Analog Devices, specialized in high-frequency RF ICs including switches, amplifiers, and MMICs for defense, communications, and instrumentation markets.

The HMC849LP4CE belongs to Hittite's high-isolation GaAs SPDT switch product line, engineered for broadband non-reflective RF path selection in demanding wireless infrastructure and test equipment applications.

FAQ

What is the maximum RF input power the HMC849LP4CE can handle before compression?

The HMC849LP4CE has a +31 dBm P1dB compression point at +5 V supply and +30 dBm at +3 V, measured over 0.35–4.0 GHz. At 6 GHz, P1dB drops to +29 dBm (+3 V) and +34 dBm (+5 V). Thermal limits govern absolute RF power handling, with continuous dissipation rated at 1.144 W (through path) and 0.441 W (termination path) at 85 °C ambient.

Does the HMC849LP4CE require external DC blocking capacitors on its RF ports?

Yes, the HMC849LP4CE RF ports (RFC, RF1, RF2) are DC-coupled and matched to 50 Ω, so external DC blocking capacitors are mandatory for AC-coupled signal paths. The datasheet specifies use of 100 pF 0402 capacitors on evaluation board 106975, and layout guidelines require proper RF grounding of capacitor pads and adjacent traces.

How does the "All Off" state function in the HMC849LP4CE?

The "All Off" state is activated when the EN pin is driven HIGH, regardless of Vctl level. In this mode, RFC, RF1, and RF2 are all terminated to 50 Ω, providing non-reflective isolation. This feature enables safe power-up sequencing, fault containment, and system-level RF mute functionality without altering Vctl logic levels.

What is the recommended PCB grounding strategy for the HMC849LP4CE?

All ground pins (10, 11), plus the exposed ground paddle on the package bottom, must be soldered directly to a solid PCB RF ground plane. Hittite's Application Note specifies a land pattern with multiple thermal vias under the paddle and recommends Rogers 4350 or Arlon 25FR substrate for evaluation boards to maintain 50 Ω impedance and minimize ground inductance.

Is the HMC849LP4CE pin-compatible with other Hittite SPDT switches like the HMC646LP4E?

Yes, the HMC849LP4CE shares identical 16-lead 4×4 mm QFN pinout and control interface (Vctl, EN, Vdd, GND, RFC/RF1/RF2) with the HMC646LP4E, enabling drop-in replacement in existing layouts. However, differences in P1dB (+31 dBm vs. +27 dBm) and isolation (60 dB vs. 50 dB typ.) require verification of system-level linearity and crosstalk margins.