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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > Single FETs, MOSFETs

NXP Semiconductors MRF373ALSR1

Name: MRF373ALSR1
Brand: NXP Semiconductors
SKU: MRF373ALSR1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MRF373ALSR1

Manufacturer:: NXP Semiconductors

Category:: Single FETs, MOSFETs

Package:: NI-360S

Datasheet:: MRF373ALSR1.pdf

Description:: RF MOSFET LDMOS 32V NI360

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MRF373ALSR1 from Freescale Semiconductor is an N-channel enhancement-mode lateral RF power MOSFET designed for broadband common-source amplifier applications in 32 V transmitter equipment operating from 470 to 860 MHz. It delivers 75 W CW output power at 860 MHz with 18.2 dB power gain and 60% drain efficiency, housed in the NI-360S (Case 360C-05) package with drain, gate, and source terminals.

For engineers reviewing the MRF373ALSR1 datasheet, MRF373ALSR1 pinout, MRF373ALSR1 application, or MRF373ALSR1 equivalent, key selection criteria include thermal resistance (0.63 °C/W), 10:1 VSWR ruggedness at 32 V/75 W, ESD protection class M1, RoHS compliance, and series-equivalent impedance characterization for matching network design.

Technical Context

The MRF373ALSR1 operates as a high-power RF amplifier stage in UHF broadcast and industrial transmitter systems, using lateral MOSFET architecture optimized for stability and gain flatness across 470–860 MHz. Its design incorporates integrated ESD protection (M1 Machine Model), low gold plating thickness (40 μ″ on leads), and thermal performance validated to 150 °C case temperature.

It is characterized with series-equivalent large-signal impedance parameters (e.g., Z_source = 0.56 + j0.06 Ω, Z_load = 1.65 + j0.22 Ω at 860 MHz), enabling precise narrowband matching network synthesis. The device supports CW operation only and is not rated for pulsed or digital modulation without external derating and thermal management.

Key Specifications

Parameter	Value and Actual Design Meaning
Frequency Range	470–860 MHz - Validated for stable gain and efficiency across full UHF TV broadcast band.
Output Power (CW)	75 W @ 860 MHz, 32 V - Sustained continuous-wave power level requiring heatsink capable of 0.63 °C/W junction-to-case thermal path.
Power Gain	18.2 dB typical @ 860 MHz - Enables single-stage amplification from driver-level input to final output in transmitter chains.
Drain Efficiency	60% typical @ 860 MHz - Reduces DC power consumption and thermal load compared to lower-efficiency alternatives.
VSWR Tolerance	10:1 @ 32 V, 860 MHz, 75 W - Withstands severe load mismatch without failure, critical for antenna-coupled transmitter front-ends.
Thermal Resistance	0.63 °C/W (Junction-to-Case) - Defines minimum heatsink thermal resistance required to maintain T_J ≤ 200 °C under full load.
ESD Rating	Machine Model Class M1 - Minimum protection level per JEDEC JS-001, suitable for automated handling in production environments.

Pinout & Package

Package: NI-360S (Case 360C-05), hermetically sealed ceramic/metal flange-mount package with insulated lid, 3-terminal configuration, RoHS compliant, supplied in tape-and-reel (500 units per 32 mm, 13-inch reel).

Pin/Terminal	Circuit Role	Design Meaning
1. Drain	High-current RF power output node	Connected to output matching network and heatsink; carries full RF output current and DC bias (32 V).
2. Gate	RF input control terminal	High-impedance node requiring stable DC bias (V_GS(Q) = 2.5–4.5 V) and RF input matching network.
3. Source	Common reference and RF return path	DC ground reference and RF return; must be low-inductance connection to minimize instability and improve gain flatness.

Key Features

Feature	Design Value
Integrated ESD Protection	Class M1 Machine Model rating ensures robustness during PCB assembly and handling without external protection circuitry.
Thermal Stability	Rated for 150 °C case temperature and 200 °C junction temperature, enabling reliable operation in high-ambient industrial enclosures.
Series-Equivalent Impedance Data	Published Z_source and Z_load values (e.g., 0.56 + j0.06 Ω / 1.65 + j0.22 Ω @ 860 MHz) simplify narrowband matching network design.
Low Gold Plating Thickness	40 μ″ nominal on leads reduces intermetallic growth risk and improves long-term solder joint reliability in thermal cycling environments.
10:1 VSWR Ruggedness	Guaranteed survival under worst-case load mismatch at full 75 W CW output, eliminating need for external circulators or isolators in many UHF transmitters.

Applications

UHF Broadcast Transmitter Final Stage	Industrial RF Heating Amplifier
Use Scenario: Final RF power amplification stage in analog/digital terrestrial TV transmitters operating in 470–860 MHz band. IC Role / Device Role / Timing Role: High-efficiency, high-power RF power MOSFET delivering 75 W CW output into 50 Ω load with minimal distortion. Use Value: Delivers 60% drain efficiency and 18.2 dB gain at 860 MHz, reducing cooling requirements and simplifying driver stage design.	Use Scenario: RF energy source in industrial dielectric heating systems for plastic welding, food processing, or material drying. IC Role / Device Role / Timing Role: Fixed-frequency CW RF power amplifier operating at fixed UHF frequency (e.g., 860 MHz) with high thermal margin. Use Value: Withstands 10:1 VSWR under mismatched load conditions common in variable-material heating cavities without protection circuitry.
Land Mobile Radio Base Station PA	RF Test Equipment Driver Amplifier
Use Scenario: High-linearity power amplifier in wideband land mobile radio base stations covering 470–860 MHz public safety bands. IC Role / Device Role / Timing Role: Common-source broadband amplifier with stable gain flatness and low IMD generation when properly biased and matched. Use Value: Characterized series-equivalent impedances enable repeatable matching network implementation across production units.	Use Scenario: Medium-power driver stage in RF signal generators, spectrum analyzers, or automated test equipment requiring clean, stable CW output. IC Role / Device Role / Timing Role: Fixed-bias RF power amplifier providing calibrated 75 W output for system-level verification and calibration. Use Value: Low C_iss (98.5 pF) and C_rss (2 pF) support wideband stability; RoHS-compliant lead finish ensures compatibility with modern assembly processes.

UHF Broadcast Transmitter Final Stage

Industrial RF Heating Amplifier

Use Scenario: Final RF power amplification stage in analog/digital terrestrial TV transmitters operating in 470–860 MHz band.

IC Role / Device Role / Timing Role: High-efficiency, high-power RF power MOSFET delivering 75 W CW output into 50 Ω load with minimal distortion.

Use Value: Delivers 60% drain efficiency and 18.2 dB gain at 860 MHz, reducing cooling requirements and simplifying driver stage design.

Use Scenario: RF energy source in industrial dielectric heating systems for plastic welding, food processing, or material drying.

IC Role / Device Role / Timing Role: Fixed-frequency CW RF power amplifier operating at fixed UHF frequency (e.g., 860 MHz) with high thermal margin.

Use Value: Withstands 10:1 VSWR under mismatched load conditions common in variable-material heating cavities without protection circuitry.

Land Mobile Radio Base Station PA

RF Test Equipment Driver Amplifier

Use Scenario: High-linearity power amplifier in wideband land mobile radio base stations covering 470–860 MHz public safety bands.

IC Role / Device Role / Timing Role: Common-source broadband amplifier with stable gain flatness and low IMD generation when properly biased and matched.

Use Value: Characterized series-equivalent impedances enable repeatable matching network implementation across production units.

Use Scenario: Medium-power driver stage in RF signal generators, spectrum analyzers, or automated test equipment requiring clean, stable CW output.

IC Role / Device Role / Timing Role: Fixed-bias RF power amplifier providing calibrated 75 W output for system-level verification and calibration.

Use Value: Low C_iss (98.5 pF) and C_rss (2 pF) support wideband stability; RoHS-compliant lead finish ensures compatibility with modern assembly processes.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MRF373ALR1	Same die, NI-360 (Case 360B-05) package; higher R_θJC = 0.89 °C/W vs. 0.63 °C/W for MRF373ALSR1.	Lower thermal performance limits maximum CW output in thermally constrained designs; identical electrical specs otherwise.	Select MRF373ALR1 only if legacy board layout uses Case 360B-05 footprint and thermal margin ≥ 0.89 °C/W is available.
MRFE6VP61K25H	NXP successor LDMOS; 1.2 kW P1dB, 600–1000 MHz, R_θJC = 0.15 °C/W, requires different bias and matching networks.	Designed for next-generation high-efficiency, high-power UHF infrastructure; not drop-in compatible due to pinout, bias, and thermal interface differences.	Consider MRFE6VP61K25H for new designs requiring >10× power scaling and improved efficiency; MRF373ALSR1 remains valid for legacy repair or low-volume replacement.

Compared with MRF373ALR1, the MRF373ALSR1 offers superior thermal resistance (0.63 vs. 0.89 °C/W) enabling higher sustained output in compact heatsinks; compared with MRFE6VP61K25H, it provides proven UHF stability and simpler biasing but lacks scalability beyond 75 W CW.

Availability

MRF373ALSR1 is available at Aetrix Electronics and suitable for UHF broadcast transmitters, industrial RF heating systems, and land mobile radio base stations requiring stable component supply and long-lifecycle support for legacy infrastructure maintenance.

Supply support for MRF373ALSR1 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 was a global semiconductor manufacturer specializing in RF power, microcontrollers, and analog solutions before its acquisition by NXP Semiconductors in 2015.

The MRF373ALSR1 belongs to Freescale's RF Power Lateral MOSFET product line, engineered for rugged, high-efficiency UHF amplifier applications in commercial broadcast and industrial RF systems.

FAQ

What is the maximum continuous drain current rating for the MRF373ALSR1?

The MRF373ALSR1 does not specify a maximum continuous drain current (I_D) rating directly. Instead, its safe operating area is defined by total device dissipation (278 W at T_C = 25°C, derated at 1.59 W/°C above 25°C) and junction temperature limit (200 °C). At 32 V drain voltage and 75 W output, typical drain current is ~2.3 A RMS, but actual current depends on bias point and waveform. Designers must verify thermal design to ensure T_J ≤ 200 °C under operating conditions. The MRF373ALSR1 datasheet emphasizes VSWR ruggedness and thermal resistance over current limits.

Is the MRF373ALSR1 pin-compatible with the MRF373ALR1?

No, the MRF373ALSR1 is not pin-compatible with the MRF373ALR1. While both share identical terminal functions (Drain, Gate, Source), they use different packages: MRF373ALSR1 uses NI-360S (Case 360C-05), whereas MRF373ALR1 uses NI-360 (Case 360B-05). The mechanical outlines differ - including flange dimensions, lid height, and mounting hole positions - making direct PCB footprint substitution impossible without layout revision. The MRF373ALSR1 also has lower thermal resistance (0.63 °C/W vs. 0.89 °C/W), reflecting its enhanced thermal construction.

Does the MRF373ALSR1 support pulsed RF operation?

The MRF373ALSR1 datasheet specifies only CW (continuous wave) performance - including 75 W output, 18.2 dB gain, and 60% efficiency at 860 MHz - and does not characterize pulsed operation. Its safe operating area, thermal time constants, and VSWR ruggedness are validated for CW conditions. For pulsed applications, designers must perform independent SOA analysis using peak pulse power, duty cycle, and thermal transient response data not provided in the official Freescale documentation for the MRF373ALSR1.

What is the gate threshold voltage range for the MRF373ALSR1?

The gate threshold voltage (V_GS(th)) for the MRF373ALSR1 is specified as 2.0–4.0 Vdc, measured at V_DS = 10 V and I_D = 200 μA. This range reflects process variation across production lots and confirms the device's enhancement-mode behavior - requiring positive gate bias to conduct. The quiescent gate voltage (V_GS(Q)) under operating conditions (V_DS = 32 V, I_DQ = 100 mA) is 2.5–4.5 Vdc, indicating stable Class AB biasing capability. These values are critical for designing stable gate bias networks that prevent thermal runaway.

Why is the MRF373ALSR1 marked "NOT RECOMMENDED FOR NEW DESIGN"?

The "NOT RECOMMENDED FOR NEW DESIGN" notice on the MRF373ALSR1 datasheet reflects Freescale's product lifecycle status at the time of publication (Rev. 7, September 2008), indicating the part was nearing obsolescence or had been superseded by newer LDMOS devices (e.g., NXP's MRFE6VP61K25H). It signals that while the MRF373ALSR1 remains fully functional and supported for repair and legacy production, Freescale no longer promoted it for newly initiated projects due to advances in efficiency, power density, and ruggedness. Aetrix Electronics continues to supply the MRF373ALSR1 for ongoing maintenance and replacement needs.

MRF373ALSR1 Specifications

Product attributes: Attribute value

Manufacturer:: NXP Semiconductors

Series:: -

Package/Case:: NI-360S

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Technology:: LDMOS

Configuration:: -

Frequency:: 860MHz

Gain:: 18.2dB

Voltage - Test:: 32 V

Current Rating (Amps):: -

Noise Figure:: -

Current - Test:: 200 mA

Power - Output:: 75W

Voltage - Rated:: 70 V

Grade:: -

Qualification:: -

Mounting Type:: Chassis Mount

Supplier Device Package:: NI-360S

MRF373ALSR1 FAQ

1.How can I place an order for MRF373ALSR1 through Aetrix?

Please submit a Request for Quotation (RFQ) for MRF373ALSR1 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for MRF373ALSR1 reliable?

The price and inventory of MRF373ALSR1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MRF373ALSR1 is usually 5 days.

3.What payment methods are accepted for MRF373ALSR1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MRF373ALSR1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MRF373ALSR1?

MRF373ALSR1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MRF373ALSR1 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for MRF373ALSR1?

For technical support, including MRF373ALSR1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MRF373ALSR1 requirements.

6.How does Aetrix verify that MRF373ALSR1 is sourced from the original manufacturer or authorized distributors?

All MRF373ALSR1 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MRF373ALSR1 meets industry standards.

7.What is the process for return or replacement of MRF373ALSR1?

All MRF373ALSR1 units undergo pre-shipment inspection (PSI). If there is an issue with MRF373ALSR1, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The MRF373ALSR1 part is unused and in its original packaging.

Return procedure for MRF373ALSR1:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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