NXP Semiconductors MRF7S18125BHR5

Overview

MRF7S18125BHR5 from NXP Semiconductors (formerly Freescale) is an N-channel enhancement-mode lateral RF power MOSFET designed for GSM and GSM EDGE base station final-stage amplification in the 1800–2000 MHz band. It delivers 125 W CW output at 1930 MHz with 16.5 dB power gain and 55% drain efficiency under 28 Vdc, 1100 mA bias - optimized for Class AB/C operation in macrocell infrastructure.

For engineers reviewing the MRF7S18125BHR5 datasheet, MRF7S18125BHR5 pinout, MRF7S18125BHR5 application, or MRF7S18125BHR5 equivalent, key selection criteria include its 1930–1990 MHz bandwidth, 140 W P1dB compression point, 5:1 VSWR ruggedness, integrated ESD protection (HBM Class 1B), and NI-780 metal-ceramic package with validated thermal resistance of 0.31 °C/W at 125 W CW.

Technical Context

This device employs a laterally diffused MOS (LDMOS) structure with internal input/output matching networks, enabling direct integration into 50 Ω systems without external impedance transformation. Its gate threshold voltage (1.2–2.7 Vdc) and quiescent gate voltage (2.7 Vdc typical) support stable Class AB biasing using simple resistive divider networks.

Thermal design is anchored by a low R_θJC of 0.31 °C/W (at 125 W CW, T_C = 81°C), enabling reliable operation up to 150°C case temperature and 225°C junction temperature. The device is characterized with series-equivalent large-signal impedances (e.g., Z_source = 1.13 − j3.06 Ω at 1960 MHz), supporting precise load-pull tuning for spectral compliance in EDGE modulation.

Key Specifications

Pinout & Package

Package: NI-780 (Case 465-06, Style 1), metal-ceramic flange-mount package with copper-tungsten base and ceramic lid. Thermal path optimized via solderable flange (1.340″ × 0.385″ footprint); max case temperature 150°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF7S18125BHR5, the BHSR5 variant trades thermal performance for compactness, while PD57018-E offers second-source assurance at the cost of 0.5 dB gain and 3% efficiency loss - both require validation of gate bias network and output matching stability.

Availability

MRF7S18125BHR5 is available at Aetrix Electronics and suitable for GSM macrocell transmitters, EDGE base station power amplifiers, multi-carrier cellular PAs, and ruggedized remote radio heads requiring stable component supply across extended product lifecycles.

Supply support for MRF7S18125BHR5 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

NXP Semiconductors is a global semiconductor leader specializing in high-performance RF, automotive, and secure connectivity solutions, with deep heritage in RF power from its Freescale acquisition.

The MRF7S18125BHR5 belongs to NXP's high-power LDMOS portfolio, engineered specifically for energy-efficient, spectrally clean cellular infrastructure amplifiers operating in licensed sub-2 GHz bands.

FAQ

What is the maximum continuous drain voltage rating for the MRF7S18125BHR5?

The MRF7S18125BHR5 has a maximum drain-source voltage (V_DSS) rating of +65 Vdc, with a minimum of −0.5 Vdc. This rating defines the absolute limit for DC bias and transient voltage spikes during operation - exceeding +65 Vdc risks permanent gate oxide damage or avalanche breakdown. Designers must ensure all transient suppression circuits clamp below this threshold, especially during VSWR events.

Does the MRF7S18125BHR5 require external matching networks for 50 Ω systems?

No - the MRF7S18125BHR5 is internally matched for 50 Ω operation across its 1930–1990 MHz band. Freescale's characterization data confirms input return loss of −12 dB (typical) and output match validated via series-equivalent Z_source/Z_load parameters. External matching is only needed for non-50 Ω architectures or harmonic suppression beyond fundamental band.

What is the thermal resistance (R_θJC) of the MRF7S18125BHR5 at full-rated power?

The MRF7S18125BHR5 exhibits a thermal resistance of 0.31 °C/W from junction to case when operated at 125 W CW with case temperature maintained at 81°C. This value is measured per AN1955 methodology and enables accurate junction temperature prediction: T_J = T_C + (P_DC × R_θJC). At 125 W CW and 55% efficiency, P_DC ≈ 227 W, yielding ΔT ≈ 70°C above case temperature.

Can the MRF7S18125BHR5 be used in Class C mode for GSM applications?

Yes - the MRF7S18125BHR5 is explicitly qualified for both Class AB and Class C operation in GSM base station applications. Its lateral MOSFET structure and gate threshold characteristics support efficient saturated switching at 28 Vdc bias. Typical Class C performance includes higher efficiency (>65%) at reduced linearity, making it suitable for constant-envelope GSM GMSK modulation where spectral purity is maintained via filtering.

What ESD protection level does the MRF7S18125BHR5 provide?

The MRF7S18125BHR5 incorporates integrated ESD protection rated to HBM Class 1B (≥500 V), Machine Model Class A, and CDM Class IV per JESD22 standards. This level protects against common handling and assembly electrostatic discharges but does not replace system-level TVS protection for lightning or cable discharge events in deployed base stations.