NXP Semiconductors MRF9120LR3

Overview

MRF9120LR3 from Freescale Semiconductor is an N-channel enhancement-mode lateral RF power MOSFET designed for broadband common-source amplifier applications in 26 V base station equipment operating from 865 to 895 MHz. It delivers 120 W CW output power at 880 MHz, 16 dB power gain, and 51% drain efficiency under 26 Vdc, 1000 mA quiescent bias - optimized for IS-95 CDMA pilot, sync, paging, and traffic channel amplification.

For engineers reviewing the MRF9120LR3 datasheet, MRF9120LR3 pinout, MRF9120LR3 application, or MRF9120LR3 equivalent, this device requires attention to gate threshold voltage (2–4 Vdc), thermal resistance (0.45 °C/W), VSWR ruggedness (10:1 @ 120 W CW), series-equivalent impedance matching (e.g., Z_load = 4.6 − j0.32 Ω @ 880 MHz), and RoHS-compliant low-gold plating (40 μ″ nominal on leads).

Technical Context

The MRF9120LR3 employs a lateral MOSFET architecture with integrated ESD protection (HBM Class 1, MM Class M1) and is characterized using series-equivalent large-signal impedance parameters for precise broadband matching. Its design emphasizes insertion phase flatness and thermal stability up to 200 °C junction temperature.

It operates in Class AB push-pull configuration with internal input matching, supporting two-tone PEP testing at 100 kHz tone spacing. Functional validation includes IMD performance (−31 dBc typ. @ 120 W PEP, 880 MHz), adjacent channel power ratio (−45 dBc @ 750 kHz offset), and robust 10:1 VSWR tolerance at full 120 W CW output.

Key Specifications

Pinout & Package

Package: NI-860 (Case 375B-04, Style 1), hermetically sealed ceramic/metal flange package with solderable lid and insulated base. Dimensions: 34.16 mm × 22.07 mm × 10.29 mm (L × W × H), 5-terminal configuration with dual drain, dual gate, and common source.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF9120LR3, the MRF9045LR5 trades 120 W broadband power for millimeter-wave readiness and smaller size, while the PD57018-E sacrifices VSWR ruggedness and absolute output for integration-friendly packaging - neither matches the MRF9120LR3's combination of 120 W CW, 10:1 VSWR tolerance, and verified 865–895 MHz IS-95 performance.

Availability

MRF9120LR3 is available at Aetrix Electronics and suitable for CDMA base station final amplifiers, IS-95 pilot channel transmitters, broadband repeater output stages, and industrial RF heating drivers requiring stable component supply across extended production lifecycles.

Supply support for MRF9120LR3 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 was a global semiconductor company specializing in RF power, microcontrollers, and analog solutions before its acquisition by NXP in 2015. It pioneered high-voltage lateral MOSFETs for cellular infrastructure.

The MRF9120LR3 belongs to Freescale's MRF9xxx RF power transistor family, engineered specifically for high-efficiency, high-ruggedness 26 V base station amplifiers operating in the 800–900 MHz band.

FAQ

What is the maximum continuous drain current rating for the MRF9120LR3?

The MRF9120LR3 does not specify a maximum continuous drain current (I_D) rating directly; instead, it defines safe operating limits via total device dissipation (250 W at T_C = 25°C, derated 1.43 W/°C above), junction temperature (200 °C), and case temperature (150 °C). At 26 Vdc and 1000 mA quiescent bias, the MRF9120LR3 delivers 120 W CW output - confirming its capability to sustain high pulsed and average currents within thermal constraints when properly heatsinked. Always validate current handling against actual board-level thermal performance.

Does the MRF9120LR3 require external input matching?

No - the MRF9120LR3 is internally input-matched, as confirmed in Table 4 footnotes and functional test conditions. Its series-equivalent source impedance (e.g., 3.29 − j1.3 Ω @ 880 MHz) is provided to guide external broadband matching network design from 50 Ω source to that impedance, but no discrete input matching components are required for basic functionality. The device achieves −16 dB input return loss at 120 W PEP, indicating effective built-in matching for typical 50 Ω systems.

What is the significance of the "R3" suffix in MRF9120LR3?

Per Freescale documentation, the "R3" suffix indicates tape-and-reel packaging: 250 units per 56 mm width, 13-inch diameter reel. This format supports automated SMT placement and is standard for high-volume manufacturing. The "L" in MRF9120LR3 further specifies low-gold-plating thickness (40 μ″ nominal) on the leads, enhancing long-term solder joint reliability in thermally cycled environments.

Can the MRF9120LR3 be used in Doherty amplifier configurations?

Yes - the MRF9120LR3's dual-drain, dual-gate, single-source pinout and push-pull characterization data (including two-tone IMD and efficiency measurements) confirm suitability for Doherty architectures. Its 10:1 VSWR ruggedness and stable gain flatness across 865–895 MHz allow carrier and peaking amplifier implementation without additional protection circuitry, provided gate bias networks and output combiners are designed per Freescale's recommended 880 MHz broadband test circuit.

Is the MRF9120LR3 still in active production?

No - Freescale archived the MRF9120LR3 in December 2009 (Revision 10), stating "Part no longer manufactured." However, Aetrix Electronics maintains legacy inventory with full traceability and supports ongoing production programs through lifecycle management, obsolescence mitigation, and controlled distribution of remaining stock. Engineering validation data remains fully applicable for existing designs.