NXP Semiconductors MRF9135LSR3

Overview

MRF9135LSR3 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 at 865–895 MHz. It delivers 25 W average output power with 17.8 dB power gain and 25% drain efficiency under N-CDMA conditions at 880 MHz, featuring internal matching, 10:1 VSWR ruggedness, and integrated ESD protection.

For engineers reviewing the MRF9135LSR3 datasheet, MRF9135LSR3 pinout, MRF9135LSR3 application, or MRF9135LSR3 equivalent, this device is selected for high-linearity, high-efficiency RF power amplification in IS-95/N-CDMA infrastructure where thermal stability, phase flatness, and mismatch tolerance are critical design requirements.

Technical Context

This lateral MOSFET operates in Class AB with gate threshold voltage of 2.8 V (typ), quiescent gate voltage of 3.7 V (typ) at IDQ = 1100 mA, and exhibits low output capacitance (Coss = 109 pF) and reverse transfer capacitance (Crss = 4.4 pF) to support broadband impedance matching across 865–895 MHz.

It is characterized using series-equivalent large-signal impedance parameters (e.g., Zsource = 1.17 − j0.24 Ω, Zload = 1.32 − j0.07 Ω at 895 MHz), enabling precise external matching network design; its 0.6 °C/W junction-to-case thermal resistance supports stable operation at up to 200 °C junction temperature under 135 W CW stress.

Key Specifications

Pinout & Package

Package: NI-780S (Case 465A-06, Style 1), hermetically sealed ceramic/metal flange-mount package with gold-plated leads (40 µ″ nominal). Designed for high-power RF PCB mounting with thermal path through flange.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF9135LSR3, the MRFE6VP6300H offers higher power headroom but demands more complex matching and cooling, while the MRF9045N shares mechanical compatibility but sacrifices 2.3 dB gain and 4% efficiency in the 865–895 MHz band-making MRF9135LSR3 the optimal balance of linearity, ruggedness, and ease of integration for CDMA-specific base station amplifiers.

Availability

MRF9135LSR3 is available at Aetrix Electronics and suitable for CDMA base station transmitters, public safety radio amplifiers, cellular repeaters, and IS-95 pilot channel modules requiring stable component supply, long-lifecycle support, and traceable sourcing for telecom infrastructure programs.

Supply support for MRF9135LSR3 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, linearity, and thermal reliability in high-volume telecom applications.

The MRF9135LSR3 belongs to Freescale's MRF91xxL family of lateral MOSFETs engineered specifically for 800–900 MHz IS-95/N-CDMA base station power amplification with internal matching and 10:1 VSWR capability.

FAQ

What is the maximum continuous drain current rating for the MRF9135LSR3?

The MRF9135LSR3 does not specify a maximum continuous drain current (ID) rating directly; instead, it defines safe operating limits via total device dissipation (298 W at TC = 25°C, derated 1.7 W/°C above), junction temperature (200 °C), and VSWR stress (135 W CW at 10:1 mismatch). Under typical 26 V, 1100 mA quiescent bias, peak drain current reaches ~12 A during RF swing-well within thermal and voltage limits defined in Table 1.

Does the MRF9135LSR3 require external matching networks for 880 MHz operation?

No-the MRF9135LSR3 is internally matched for 865–895 MHz operation, as confirmed by Freescale's test circuit data and impedance tables (Figure 13). While external tuning elements (e.g., C2, C4 in Figure 1) may be used for fine optimization, the device achieves specified gain, efficiency, and ACPR without mandatory external matching components at 880 MHz.

What is the gate threshold voltage range for the MRF9135LSR3, and how does it affect biasing?

The MRF9135LSR3 has a gate threshold voltage (VGS(th)) range of 2.0–4.0 V (min–max) at VDS = 10 V and ID = 450 µA, with a typical value of 2.8 V. This wide range necessitates adjustable gate bias (e.g., via potentiometer or DAC-controlled current source) to set IDQ = 1100 mA precisely, as gate quiescent voltage (VGS(Q)) varies from 3.25–5.0 V (typ 3.7 V) under operating conditions.

Can the MRF9135LSR3 be used in pulsed RF applications outside the 865–895 MHz band?

The MRF9135LSR3 is characterized and optimized for continuous-wave and N-CDMA modulated signals within 865–895 MHz. While its lateral MOSFET structure supports pulsed operation, Freescale's datasheet provides no validated performance data outside this band or for pulse widths < 10 µs. Use outside this scope requires full characterization of gain, efficiency, and thermal response for the specific pulse profile and frequency.

What is the lead finish specification for the MRF9135LSR3, and why does it matter for soldering?

The MRF9135LSR3 uses a nominal 40 µ″ gold plating thickness on leads, per Freescale's specification. This thin, pure gold layer ensures reliable wire bonding and solder wetting while preventing oxidation during storage and reflow. It is compatible with standard SnPb and Pb-free solder profiles, but excessive dwell time or peak temperature (>375 °C) risks gold embrittlement-reflow must follow JEDEC J-STD-020 guidelines for moisture-sensitive level 3 devices.