NXP Semiconductors MRF18090AR3

Overview

MRF18090AR3 from Freescale Semiconductor is an N-channel enhancement-mode lateral RF power MOSFET designed for GSM and GSM EDGE base station amplifiers operating at 1805–1880 MHz. It delivers 90 W CW output power at 26 Vdc with 13.5 dB typical power gain and 52% typical drain efficiency, and is rated for 10:1 VSWR tolerance under full-power operation.

For engineers reviewing the MRF18090AR3 datasheet, MRF18090AR3 pinout, MRF18090AR3 application, or MRF18090AR3 equivalent, this device is selected for high-efficiency, high-linearity Class AB RF power stages in cellular infrastructure where thermal stability, ESD robustness, and impedance-matched ease-of-use are critical design requirements.

Technical Context

This LDMOS transistor operates in common-source configuration with internally matched input and output impedances optimized for 1805–1880 MHz band. Its large-signal characterization includes series-equivalent source/load impedances (e.g., Z_source = 1.10 – j5.85 Ω at 1805 MHz), enabling direct integration into microstrip-based matching networks without external tuning.

Thermal design is supported by a low junction-to-case thermal resistance of 0.7 °C/W and a maximum case temperature rating of 150 °C. The device features integrated ESD protection rated to HBM Class 2 and MM Class M3, and is characterized for stable performance across 100–200 °C junction temperature range.

Key Specifications

Pinout & Package

Package: Case 465B-03, Style 1 (NI-880 metal-ceramic flange package with insulated lid). Dimensions: 34.16 mm × 13.8 mm × 5.08 mm (L×W×H), flange-mounted with M3 screw centering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF18090AR3, the MRFE6VP61K25HR5 provides broader bandwidth at the cost of tighter gate bias control, while the BLF188XR offers superior ruggedness but demands mechanical requalification - neither is pin-compatible, and both require updated thermal and RF layout validation.

Availability

MRF18090AR3 is available at Aetrix Electronics and suitable for GSM base station transmitters, GSM EDGE multicarrier amplifiers, and TDMA cellular repeater PAs requiring stable component supply for legacy infrastructure maintenance and spare-part provisioning.

Supply support for MRF18090AR3 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 semiconductors for wireless infrastructure, automotive radar, and industrial heating applications.

The MRF18090AR3 belongs to Freescale's MRF-series LDMOS RF power transistor family, engineered specifically for high-efficiency, high-reliability macro base station amplifiers in licensed cellular bands.

FAQ

What is the maximum continuous drain current rating for the MRF18090AR3?

The MRF18090AR3 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 90 W CW output with 52% efficiency, the MRF18090AR3 draws approximately 6.9 A DC from the 26 V supply, resulting in ~180 W total dissipation - well within its thermal envelope when properly heatsinked.

Does the MRF18090AR3 require external matching networks?

Yes, the MRF18090AR3 is internally matched for ease of use but still requires external input and output matching networks to transform its intrinsic impedances (e.g., Z_source = 1.10 – j5.85 Ω, Z_load = 1.15 – j2.16 Ω at 1805 MHz) to 50 Ω. Freescale provides verified microstrip layouts in the datasheet (Figures 1–4) for repeatable 90 W performance without iterative tuning.

What is the gate threshold voltage range for the MRF18090AR3?

The MRF18090AR3 has a gate quiescent voltage (V_GS(Q)) range of 2.5–4.5 Vdc at V_DS = 26 Vdc and I_D = 750 mAdc, indicating a nominal threshold near 3.7 Vdc. This value is measured under large-signal Class AB bias conditions and reflects the gate voltage required to establish the recommended 750 mA idle current - not a small-signal V_GS(th) parameter.

Can the MRF18090AR3 be used in Class C amplifier configurations?

No - the MRF18090AR3 is explicitly characterized and qualified for Class AB operation in GSM and GSM EDGE applications. Its thermal design, linearity optimization, and large-signal impedance data assume AB bias (I_DQ = 750 mA); Class C operation would exceed safe junction temperature limits and degrade IMD performance without validated drive and load conditions.

Is the MRF18090AR3 still in active production?

No - per Freescale Document Number MRF18090A Rev. 8 (Oct. 2008) and archival note dated Dec. 2010, the MRF18090AR3 is discontinued and no longer manufactured. Aetrix Electronics supplies remaining authorized inventory with full traceability for legacy system repair, spares fulfillment, and end-of-life program support.