NXP Semiconductors MRF372R3

Overview

MRF372R3 from Freescale Semiconductor is an N-channel enhancement-mode lateral RF power MOSFET designed for large-signal common-source amplifier applications in 32 V broadband transmitter equipment operating from 470 to 860 MHz. It delivers 180 W PEP output power, 17 dB narrowband power gain, and 36% drain efficiency at 857–863 MHz with 800 mA quiescent drain current.

For engineers reviewing the MRF372R3 datasheet, MRF372R3 pinout, MRF372R3 application, or MRF372R3 equivalent, this device requires attention to its 5-pin case 375G-04 package, series-equivalent source/load impedance matching (e.g., Z_source = 3.18 − j1.46 Ω at 860 MHz), thermal resistance of 0.5 °C/W, and ESD protection class HBM-1 / MM-M3.

Technical Context

This device operates as a high-power RF amplifier in push-pull or balanced configurations, with gate threshold voltage specified at 2–4 V and gate quiescent voltage at 2.5–4.5 V under 32 V drain bias. Its dynamic characteristics include C_iss = 260 pF, C_oss = 69 pF, and Crss = 2.5 pF at 1 MHz, supporting broadband impedance matching across 470–863 MHz.

The MRF372R3 is internally matched for 50 Ω systems in both narrowband (857–863 MHz) and broadband (470–860 MHz) circuits, with characterized series-equivalent large-signal impedances provided for source (e.g., 4.46 − j2.57 Ω at 470 MHz) and load (e.g., 8.27 − j1.00 Ω at 860 MHz) networks.

Key Specifications

Pinout & Package

Package: Case 375G-04, Style 1 - metal-ceramic flange-mount package with insulated lid, 1.340″ × 0.385″ footprint, 0.102″ height, and 5-terminal configuration optimized for RF grounding and thermal conduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF372R3, the MRFE6VP61K25H offers significantly higher power and efficiency but demands new PCB layout and biasing, while the PD85003 delivers superior narrowband gain and output at 860 MHz but cannot replace MRF372R3 in broadband 470–660 MHz applications without redesign.

Availability

MRF372R3 is available at Aetrix Electronics and suitable for UHF broadcast transmitters, cable headend amplifiers, and wireless repeater systems requiring stable component supply, long-lifecycle support, and traceable sourcing for industrial RF power applications.

Supply support for MRF372R3 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 broadcast, industrial, and communications infrastructure.

The MRF372R3 belongs to Freescale's lateral N-channel RF power MOSFET product line, engineered specifically for high-efficiency, high-linearity UHF amplifier stages in commercial and industrial transmitter equipment.

FAQ

What is the maximum continuous drain current rating for the MRF372R3?

The MRF372R3 has a maximum continuous drain current (I_D) rating of 17 A at T_C = 25°C. This rating assumes proper heatsinking and derating per the 2.0 W/°C thermal derating curve above 25°C ambient. Actual operating current depends on bias point, duty cycle, and thermal management - for example, the device operates at 800 mA I_DQ in narrowband 180 W PEP applications and 1000 mA in broadband mode. The MRF372R3 must never exceed its 350 W total dissipation limit.

Does the MRF372R3 require external input/output matching networks?

The MRF372R3 is internally matched for ease of use in standard 50 Ω systems, eliminating the need for discrete input/output matching networks in Freescale's reference narrowband (860 MHz) and broadband (470–860 MHz) circuits. However, external tuning components (e.g., variable capacitors C2/C13, chip inductors L1–L4) are still required in the DC bias networks to optimize gain, efficiency, and IMD performance per application. Matching remains necessary for non-50 Ω loads or custom impedance targets.

What is the gate threshold voltage range for the MRF372R3?

The MRF372R3 has a gate threshold voltage (V_GS(th)) range of 2.0–4.0 Vdc, measured at V_DS = 10 V and I_D = 200 μA. This parameter defines the minimum gate voltage needed to initiate conduction. In practical operation, the device is biased with a gate quiescent voltage (V_GS(Q)) of 2.5–4.5 Vdc at V_DS = 32 V and I_D = 100 mA, ensuring stable Class AB operation. Gate drive must remain within the −0.5 to +15 V absolute maximum rating.

Can the MRF372R3 be used in push-pull configuration?

Yes, the MRF372R3 is explicitly characterized and recommended for push-pull operation, as confirmed by measurement notes stating "Measurement made with device in push-pull configuration" and layout diagrams showing dual gate/drain terminals. Its symmetrical 5-pin Style 1 package (Pins 1&2 = drains, Pins 3&4 = gates, Pin 5 = shared source) supports balanced drive and load sharing. Push-pull use improves even-order harmonic suppression and enables higher effective output power while maintaining linearity - critical for COFDM and multi-carrier signals.

What does the 'R3' suffix indicate in MRF372R3?

The 'R3' suffix in MRF372R3 denotes packaging: 250 units per 56 mm, 13-inch tape-and-reel. This differs from the 'R5' variant (50 units per same reel size). Both share identical electrical, thermal, and mechanical specifications - only packaging quantity and reel configuration differ. The R3 format supports high-volume automated assembly, while R5 suits prototyping or low-volume production. No functional or performance distinction exists between MRF372R3 and MRF372R5 beyond packaging.