NXP Semiconductors MRF281ZR1

Overview

MRF281ZR1 from Freescale Semiconductor is a lateral N-channel enhancement-mode RF power MOSFET designed for broadband cellular base station amplifiers operating at 1930–1990 MHz. It delivers 4 W PEP output power with 11 dB power gain and 30% drain efficiency at 26 Vdc, optimized for Class A/AB operation in PCS/PCN infrastructure applications.

For engineers reviewing the MRF281ZR1 datasheet, MRF281ZR1 pinout, MRF281ZR1 application, or MRF281ZR1 equivalent, this device requires attention to its 3-pin NI-200Z package, series-equivalent impedance matching (Z_in = 3.1 + j0.9 Ω @ 1900 MHz), thermal resistance (R_θJC = 5.74 °C/W), and rugged 10:1 VSWR tolerance at 2 GHz.

Technical Context

The MRF281ZR1 operates as a common-source RF amplifier stage with gate-threshold voltage (V_GS(th)) of 2.4–4.0 V and quiescent gate voltage (V_GS(q)) of 3.0–5.0 V at I_DQ = 25 mA. Its S-parameter characterization at high bias (I_D = 250 mA) confirms stable small-signal gain (S₂₁ = 6.01 dB @ 1 GHz, 2.63 dB @ 2 GHz) and input return loss (IRL = –16 dB typical).

It features series-equivalent large-signal impedance parameters validated across 1500–2500 MHz, enabling precise matching network design. The device supports two-tone intermodulation distortion of –31 dBc at 1930 MHz and withstands 10:1 VSWR under CW conditions at 4 W output - critical for deployed base station reliability.

Key Specifications

Pinout & Package

Package: NI-200Z (Case 458C-03, Style 1), hermetically sealed ceramic/metal flange-mount package with coplanar leads (H ≤ 0.004 inch), optimized for RF grounding and thermal conduction via flange.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF281ZR1, MRF281SR1 shares identical RF performance but demands mechanical redesign, while PD570032 offers higher gain and surface-mount convenience at the cost of ruggedness and VSWR tolerance - making MRF281ZR1 preferable for outdoor macro-cell infrastructure where reliability outweighs size.

Availability

MRF281ZR1 is available at Aetrix Electronics and suitable for PCS base station transmitter modules, WCDMA macro-cell power amplifiers, and LTE Band 2/25 active antenna systems requiring stable component supply and long-term lifecycle support.

Supply support for MRF281ZR1 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, thermal performance, and broadband matching data.

The MRF281ZR1 belongs to Freescale's MRF281 family of lateral N-channel RF LDMOS devices, engineered specifically for digital cellular base station amplifiers operating between 1000–2500 MHz with emphasis on linearity, efficiency, and field reliability.

FAQ

What is the maximum junction temperature rating for the MRF281ZR1?

The MRF281ZR1 has a maximum operating junction temperature (T_J) of 200°C, verified per Freescale's thermal characterization in Table 1. This rating enables operation in high-ambient environments such as outdoor base station cabinets, provided the case temperature remains ≤150°C and thermal resistance R_θJC = 5.74 °C/W is respected in heatsink design. The MRF281ZR1 must be mounted to a thermally conductive surface with appropriate thermal interface material to achieve this limit.

Does the MRF281ZR1 support Class AB operation at 26 Vdc?

Yes, the MRF281ZR1 is explicitly characterized for Class AB operation at 26 Vdc with I_DQ = 25 mA, delivering 4 W PEP output power, 11 dB power gain, and 30% drain efficiency at 1930 MHz. The datasheet specifies two-tone IMD (–31 dBc), input return loss (–16 dB), and series-equivalent impedances under these exact bias conditions. The MRF281ZR1's gate threshold voltage (2.4–4.0 V) and quiescent gate voltage (3.0–5.0 V) are calibrated for stable Class AB biasing in production base station amplifiers.

What package type does the MRF281ZR1 use, and how does it differ from MRF281SR1?

The MRF281ZR1 uses the NI-200Z package (Case 458C-03, Style 1), featuring a ceramic insulator and metal lid with coplanar leads (H ≤ 0.004 inch). In contrast, the MRF281SR1 uses NI-200S (Case 458B-03), which differs in lid height, insulator thickness, and lead coplanarity specification. Though electrically identical, the MRF281ZR1 and MRF281SR1 are not mechanically interchangeable - the MRF281ZR1 requires its specific footprint defined in the Case 458C-03 drawing.

Is the MRF281ZR1 RoHS compliant?

Yes, the MRF281ZR1 is RoHS compliant, as confirmed in the "Features" section of the Freescale datasheet (Rev. 6, Oct. 2008). It meets EU Directive 2011/65/EU requirements for restriction of hazardous substances, including lead-free terminations and halogen-free packaging materials. This compliance applies to all units shipped with the R1 tape-and-reel suffix (500 units per 12 mm, 7-inch reel), consistent with Freescale's PCN13232 implementation.

Can the MRF281ZR1 handle 10:1 VSWR at full output power?

Yes, the MRF281ZR1 is characterized to safely handle 10:1 VSWR at 2000 MHz with 4 W CW output power and 26 Vdc supply, as stated in the "Specified Two-Tone Performance" section. This robustness is validated under continuous-wave conditions and forms the basis for its use in outdoor base station applications where antenna mismatches may occur. The MRF281ZR1's lateral LDMOS structure and thermal design (R_θJC = 5.74 °C/W) enable this level of ruggedness without external protection circuitry.