NXP Semiconductors MRF9045LR5

Overview

MRF9045LR5 from Freescale Semiconductor is an N-channel enhancement-mode lateral RF power MOSFET designed for broadband common-source amplifier applications in 28 V base station equipment operating up to 1000 MHz. It delivers 45 W PEP output power at 945 MHz, with 18.8 dB power gain, 42% drain efficiency, and –32 dBc third-order IMD under two-tone test conditions.

For engineers reviewing the MRF9045LR5 datasheet, MRF9045LR5 pinout, MRF9045LR5 application, or MRF9045LR5 equivalent, this device is selected for high-reliability, high-linearity RF power amplification in cellular infrastructure where VSWR tolerance, thermal stability, and phase flatness are critical design constraints.

Technical Context

This LDMOS transistor operates in Class AB configuration with a gate threshold voltage of 2–4 Vdc and a typical quiescent gate voltage of 3.7 Vdc at 350 mA drain current. Its low output capacitance (Coss = 37 pF) and reverse transfer capacitance (Crss = 1.5 pF) support stable broadband matching across 930–960 MHz.

The device features integrated ESD protection (HBM Class 1), is characterized with series-equivalent large-signal impedance parameters (e.g., Z_source = 1.15 + j0.25 Ω, Z_load = 2.6 + j0.16 Ω at 945 MHz), and is rated for 150°C case temperature and 200°C junction temperature.

Key Specifications

Pinout & Package

Package: CASE 360B–05 (NI–360), ceramic/metal hermetic package with flange-mount thermal interface. Dimensions: 20.19–20.45 mm × 5.72–5.97 mm × 9.02–9.27 mm (L×W×H), 3-pin configuration.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF power transistor applications.

Compared with MRF9045LR5, MRFE6VP6450HR5 offers higher power headroom but demands layout revision and new thermal management, while PD57045S provides superior thermal performance in a smaller footprint but requires retuning of input/output networks to meet linearity targets.

Availability

MRF9045LR5 is available at Aetrix Electronics and suitable for cellular infrastructure, public safety radio, and industrial RF heating applications requiring stable component supply and long-term lifecycle support.

Supply support for MRF9045LR5 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

Freescale Semiconductor (now part of NXP Semiconductors) was a leading designer of RF power transistors for wireless infrastructure, emphasizing ruggedness, linearity, and thermal reliability.

The MRF9045LR5 belongs to Freescale's MRF9000 series of broadband LDMOS RF power transistors, engineered specifically for 800–1000 MHz base station amplifiers demanding high efficiency and VSWR resilience.

FAQ

What is the maximum operating frequency range for the MRF9045LR5?

The MRF9045LR5 is characterized and specified for operation from 930 MHz to 960 MHz, with broadband performance validated up to 1000 MHz. Typical gain and efficiency data are provided at 930, 945, and 960 MHz; operation beyond 1000 MHz is not supported by published specifications or characterization data for MRF9045LR5.

Does the MRF9045LR5 require external ESD protection circuitry?

No, the MRF9045LR5 integrates ESD protection rated to HBM Class 1 and MM Class M1 per JEDEC standards. This built-in protection eliminates the need for external TVS diodes or RC clamps on the gate terminal during normal handling and operation, though proper PCB layout grounding remains essential.

What is the recommended gate bias voltage for linear operation of the MRF9045LR5?

The MRF9045LR5 achieves optimal linearity and efficiency at a quiescent gate voltage (V_GS(Q)) of 3.7 Vdc, measured at 28 Vdc drain supply and 350 mA quiescent drain current. Deviations outside 3.5–3.9 Vdc may degrade IMD performance or reduce power-added efficiency in MRF9045LR5-based amplifiers.

Can the MRF9045LR5 be used in Class C or D amplifier topologies?

No - the MRF9045LR5 is characterized and optimized for Class AB operation only. Its gain, efficiency, and IMD specifications assume linear biasing (IDQ = 350 mA). Using it in Class C or D would exceed safe operating area limits, risk thermal runaway, and void published performance guarantees for MRF9045LR5.

Is the MRF9045LR5 RoHS compliant?

Yes, the MRF9045LR5 is RoHS compliant per the manufacturer's documentation (Rev. 11, September 2008). It contains no lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), or polybrominated diphenyl ethers (PBDE) above regulated thresholds, and meets EU Directive 2011/65/EU requirements.