NXP Semiconductors MRF7S18125BHSR3

Overview

MRF7S18125BHSR3 from Freescale Semiconductor is an N-channel enhancement-mode lateral RF power MOSFET designed for GSM and GSM EDGE base station amplifiers operating at 1930–1990 MHz. It delivers 125 W CW output at 28 V with 16.5 dB power gain and 55% drain efficiency, and supports 57 W average output under EDGE modulation with 2.6% EVM and −60 dBc spectral regrowth at 400 kHz offset.

For engineers reviewing the MRF7S18125BHSR3 datasheet, MRF7S18125BHSR3 pinout, MRF7S18125BHSR3 application, or MRF7S18125BHSR3 equivalent, key selection criteria include its NI-780S package, 1930–1990 MHz bandwidth, 125 W CW Pout capability, thermal resistance of 0.35 °C/W at 71 W CW, and integrated ESD protection rated Class 1B HBM.

Technical Context

This device employs a laterally diffused MOS (LDMOS) structure optimized for high-efficiency linear amplification in cellular infrastructure. Its internally matched input and output enable direct integration into 50 Ω systems without external matching networks, and it operates in Class AB or Class C with stable performance across −30°C to +85°C ambient temperature.

The MRF7S18125BHSR3 features series-equivalent large-signal impedance characterization for precise load-pull design, supports 5:1 VSWR tolerance at 125 W CW, and maintains <1.02 dB gain flatness over 60 MHz bandwidth - critical for wideband EDGE signal fidelity and adjacent channel leakage control.

Key Specifications

Pinout & Package

Package: NI-780S (Case 465A-06, Style 1), flange-mounted ceramic/metal hermetic package with solderable baseplate for high-power thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF7S18125BHR3, the MRF7S18125BHSR3 trades marginal thermal resistance for standardized tape-and-reel logistics and compatibility with existing NI-780S assembly lines; versus PD57018-E, it offers superior ESD robustness and tighter gain flatness but requires Freescale-specific bias network tuning.

Availability

MRF7S18125BHSR3 is available at Aetrix Electronics and suitable for GSM macro base stations, EDGE multi-carrier amplifiers, and wideband cellular repeaters requiring stable component supply, long-lifecycle support, and traceable RF power transistor sourcing.

Supply support for MRF7S18125BHSR3 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) is a global leader in RF power solutions for wireless infrastructure, with deep expertise in LDMOS technology and cellular base station design.

The MRF7S18125BHSR3 belongs to Freescale's MRF7S family of high-efficiency RF power transistors engineered specifically for 1.8–2.0 GHz GSM/EDGE macro and micro base station applications demanding high linearity and ruggedness.

FAQ

What is the maximum operating junction temperature for the MRF7S18125BHSR3?

The MRF7S18125BHSR3 has a maximum operating junction temperature (T_J) of 225°C, as specified in Table 1 of the datasheet. This high limit supports reliable operation under sustained 125 W CW output with appropriate heatsinking. Thermal design must ensure that actual junction temperature remains below this value during all operating conditions, especially at elevated ambient temperatures or reduced airflow.

Does the MRF7S18125BHSR3 require external input/output matching networks?

No, the MRF7S18125BHSR3 is internally matched for 50 Ω systems, as confirmed in the Features section and Table 4 notes. Its input and output impedances are characterized and optimized for direct integration into standard 50 Ω test fixtures and production amplifiers, eliminating discrete matching components in many designs - though fine-tuning may still be needed for specific PA architectures or efficiency targets.

What is the gate quiescent voltage specification for the MRF7S18125BHSR3?

The gate quiescent voltage (V_GS(Q)) for the MRF7S18125BHSR3 is 2.7 V typical at V_DD = 28 Vdc and I_D = 1100 mAdc (Table 4). The fixture gate voltage (V_GG(Q)) is 4–7 V due to an on-board resistive divider; actual gate bias circuitry must deliver ~2.7 V to the gate terminal itself to achieve the specified 1100 mA quiescent current.

How does the MRF7S18125BHSR3 perform under GSM EDGE modulation?

Under GSM EDGE modulation at 57 W average output, the MRF7S18125BHSR3 achieves 17 dB power gain, 39% drain efficiency, 2.6% rms EVM, −60 dBc spectral regrowth at 400 kHz offset, and −74 dBc at 600 kHz offset - all verified across the 1930–1990 MHz band. These values meet 3GPP linearity and spectral mask requirements for commercial base station deployment.

Is the MRF7S18125BHSR3 RoHS compliant and what is its ESD rating?

Yes, the MRF7S18125BHSR3 is RoHS compliant and features integrated ESD protection rated per industry standards: Human Body Model Class 1B (≥500 V), Machine Model Class A, and Charge Device Model Class IV - as documented in Table 3. This eliminates need for external ESD protection diodes in most board-level implementations.