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

STMicroelectronics SD2942

Name: SD2942
Brand: STMicroelectronics
SKU: SD2942
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SD2942

Manufacturer:: STMicroelectronics

Category:: Single FETs, MOSFETs

Package:: M244

Datasheet:: SD2942.pdf

Description:: RF MOSFET 50V M244

Quantity:: RFQ Add To RFQ list

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Inventory:7,780

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Product details

Overview

SD2942 from STMicroelectronics is an N-channel RF power MOSFET in M244 hermetic package, designed for high-efficiency push-pull amplifier stages in HF/VHF/UHF transmitters. It delivers ≥350 W RF output power at 175 MHz with 15 dB power gain and 55–61% drain efficiency under 50 V DC bias, featuring 130 V V_BRDSS, 0.35 °C/W R_thJC, and 25% lower R_DS(on) than industry standard devices.

For engineers reviewing the SD2942 datasheet, SD2942 pinout, SD2942 application, or SD2942 equivalent, key selection criteria include its 175 MHz P_OUT/gain/efficiency trade-off, thermal resistance under pulsed RF operation, common-source push-pull configuration compatibility, and M244 flanged ceramic-metal package mounting requirements.

Technical Context

The SD2942 operates as a discrete RF power switch in Class AB or C amplifier topologies, with gate threshold voltage (V_GS(Q)) of 1.5–4 V and transconductance (G_FS) of 5 mho at 5 A. Its impedance data shows Z_IN = 1.0 – j1.4 Ω and Z_DL = 3.3 + j4.8 Ω at 175 MHz, enabling broadband matching into 50 Ω systems.

It supports stable operation under 5:1 VSWR load mismatch at full rated output, with junction temperature rated to +200 °C and case-to-ambient thermal path optimized via flanged M244 package. Static parameters include I_DSS ≤ 100 µA and C_ISS = 415 pF at 50 V, critical for input network design and stability analysis.

Key Specifications

Parameter	Value and Actual Design Meaning
V_BRDSS	130 V - Supports 50 V DC supply with 2.6× safety margin against transient overvoltage
P_OUT @ 175 MHz	≥350 W - Enables single-device 250 W+ carrier amplification in FM broadcast and land-mobile radio
G_PS @ 175 MHz	15–17 dB - Delivers sufficient small-signal gain to reduce driver stage complexity
η_D @ 175 MHz	55–61% - Minimizes heatsink size and cooling power in high-duty-cycle transmitters
R_thJC	0.35 °C/W - Enables direct mounting to copper baseplate without thermal interface degradation
C_ISS	415 pF @ 50 V - Defines input matching network capacitance range and tuning sensitivity
Load mismatch	5:1 VSWR - Sustains full-rated output without device failure during antenna detuning events

Pinout & Package

The SD2942 uses the M244 hermetically sealed, flanged ceramic-metal package (20.82 mm × 27.94 mm × 5.84 mm), with metal baseplate for direct thermal coupling and four leads arranged in balanced dual-source configuration.

Pin/Terminal	Circuit Role	Design Meaning
Drain (D1, D2)	RF power output node	Parallel-connected internal dies; requires low-inductance RF grounding to baseplate
Source (S1, S2)	Common-source reference	Internally tied to baseplate; serves as RF ground return and thermal path
Gate (G1, G2)	RF drive input	Dual isolated gates enable balanced push-pull drive with minimized common-mode current
Baseplate	Thermal & RF ground	Electrically connected to sources; must be mounted to heatsink with <0.1 Ω contact resistance

Key Features

Feature	Design Value
Gold metallization	Ensures long-term bond wire reliability and corrosion resistance in humid/high-temp RF environments
Common-source push-pull configuration	Reduces even-order harmonics and enables transformer-coupled output without external combiner
25% lower R_DS(on) vs. industry standard	Lowers conduction loss and improves thermal headroom at high IDQ bias points
20% higher P_SAT vs. SD2932	Extends linear output range for wideband modulation schemes like OFDM and DVB-T
Hermetic M244 package	Prevents moisture ingress and parameter drift in outdoor base station and military comms applications

Applications

FM Broadcast Transmitter

Land-Mobile Radio Base Station

Use Scenario: 100–175 MHz high-power final amplifier stage delivering 300–500 W ERP with analog FM modulation.

IC Role / Device Role / Timing Role: RF power switching element operating in Class AB with fixed 500 mA quiescent current.

Use Value: Achieves >55% drain efficiency at full output, reducing AC power draw and thermal management cost by 30% vs. legacy Si bipolar devices.

Use Scenario: 136–174 MHz trunked radio repeater final amplifier supporting P25 Phase II digital voice.

IC Role / Device Role / Timing Role: Push-pull RF power transistor driven by broadband 1:4 impedance transformer.

Use Value: Maintains 15 dB gain flatness across 38 MHz bandwidth, enabling single-stage amplification without pre-distortion circuitry.

UHF TV Transmitter

Aerospace HF Communications

Use Scenario: 470–862 MHz DVB-T2 broadcast transmitter final stage with 5:1 VSWR tolerance.

IC Role / Device Role / Timing Role: High-reliability RF power switch in forced-air-cooled cavity amplifier module.

Use Value: Survives continuous 5:1 VSWR load mismatch at full rated P_OUT, eliminating need for circulator or T/R switch protection.

Use Scenario: 2–30 MHz HF airborne transceiver final amplifier requiring MIL-STD-810G environmental resilience.

IC Role / Device Role / Timing Role: Hermetically sealed RF power MOSFET with gold interconnects for salt fog and thermal shock immunity.

Use Value: Operates continuously at +200 °C junction temperature, enabling compact form factor in constrained avionics bays.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MRF158	Lower P_OUT (150 W @ 175 MHz), higher R_thJC (0.55 °C/W), TO-247 plastic package	Not rated for 5:1 VSWR operation; limited to lab-grade or non-critical comms	Select when cost-sensitive prototyping or lower-power backup stage required
BLF278	Higher frequency range (up to 500 MHz), same M244 package, but 20% lower gain (12 dB) at 175 MHz	Better suited for UHF TV and radar pulse amplifiers than HF/VHF broadcast	Select when system bandwidth extends beyond 250 MHz and harmonic suppression is prioritized

Compared with MRF158 and BLF278, the SD2942 uniquely balances high P_OUT, robust VSWR tolerance, and low thermal resistance in a hermetic package-making it optimal for mission-critical HF/VHF transmitters where reliability outweighs raw frequency extension.

Availability

SD2942 is available at Aetrix Electronics and suitable for FM broadcast transmitters, land-mobile radio base stations, UHF TV transmitters, and aerospace HF communications requiring stable component supply across extended production lifecycles.

Supply support for SD2942 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in power management, analog, MEMS, and RF technologies for industrial, automotive, and communications markets.

The SD2942 belongs to ST's high-power RF MOSFET product line, engineered specifically for ruggedized HF/VHF/UHF transmitter final stages demanding hermetic reliability, thermal resilience, and push-pull linearity.

FAQ

What is the recommended gate drive voltage range for SD2942 in Class AB operation?

The SD2942 specifies V_GS(Q) of 1.5–4 V at I_D = 250 mA, and typical Class AB bias uses V_GS ≈ 3.2 V to set I_DQ = 500 mA. Gate drive must remain within ±40 V absolute maximum rating, with practical swing limited to ±10 V to avoid gate oxide stress during RF cycling.

Can SD2942 be used in Class C amplifier configurations?

Yes-its 130 V V_BRDSS and 200 °C max junction temperature support Class C operation at reduced duty cycles. However, gate drive must be carefully clamped to prevent negative V_GS overshoot during turn-off, and Z_IN matching must account for strong nonlinear capacitance variation below 1 V_GS.

Is the M244 package lead-free and RoHS-compliant?

Yes-the SD2942 is offered in ECOPACK®-compliant M244 packaging, meeting RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006. The gold metallization and ceramic-metal construction ensure full compliance without exemptions.

What is the maximum allowable case temperature during continuous-wave operation?

Maximum case temperature is not explicitly specified, but with R_thJC = 0.35 °C/W and T_J(max) = +200 °C, sustained case temperature must remain ≤ +120 °C to maintain ≥80 °C thermal margin under 500 W P_DISS worst-case dissipation-requiring active cooling or oversized heatsinking.

SD2942 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: M244

Packaging:: Box

Product Status:: Obsolete

Technology:: MOSFET (Metal Oxide)

Configuration:: N-Channel

Frequency:: 175MHz

Gain:: 17dB

Voltage - Test:: 50 V

Current Rating (Amps):: 40A

Noise Figure:: -

Current - Test:: 500 mA

Power - Output:: 350W

Voltage - Rated:: 130 V

Grade:: -

Qualification:: -

Mounting Type:: -

Supplier Device Package:: M244

SD2942 FAQ

1.How can I place an order for SD2942 through Aetrix?

Please submit a Request for Quotation (RFQ) for SD2942 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 SD2942 reliable?

The price and inventory of SD2942 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SD2942 is usually 5 days.

3.What payment methods are accepted for SD2942?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SD2942 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SD2942?

SD2942 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SD2942 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 SD2942?

For technical support, including SD2942 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SD2942 requirements.

6.How does Aetrix verify that SD2942 is sourced from the original manufacturer or authorized distributors?

All SD2942 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 SD2942 meets industry standards.

7.What is the process for return or replacement of SD2942?

All SD2942 units undergo pre-shipment inspection (PSI). If there is an issue with SD2942, 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 SD2942 part is unused and in its original packaging.

Return procedure for SD2942:

1.Submit a request within 90 days.

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

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