STMicroelectronics SD2942W

Overview

SD2942W from STMicroelectronics is a gold-metallized N-channel RF power MOSFET in M244 hermetic package, designed for high-efficiency HF/VHF/UHF amplifier stages operating up to 250 MHz. It delivers ≥350 W output power at 175 MHz with 15 dB power gain, 55–61% drain efficiency, and 0.35 °C/W junction-to-case thermal resistance under 50 V DC bias.

For engineers reviewing the SD2942W datasheet, SD2942W pinout, SD2942W application, or SD2942W equivalent, key selection criteria include R_DS(on) ≤3.0 V at 10 V_GS, safe operation under 5:1 VSWR load mismatch, and thermal stability up to +200 °C junction temperature in push-pull RF final stages.

Technical Context

The SD2942W employs a common-source push-pull configuration optimized for broadband RF amplification from 25 MHz to 250 MHz. Its low R_DS(on) (≤3.0 V) and high transconductance (5 mho typical) support high-current switching with minimal conduction loss at 50 V DC supply.

Thermal design is enabled by direct metal-to-case mounting via its flanged M244 package and 0.35 °C/W R_thJC. Impedance data shows Z_IN = 1.0 − j1.4 Ω and Z_DL = 3.3 + j4.8 Ω at 175 MHz, enabling stable matching into 50 Ω systems without external stabilization networks.

Key Specifications

Pinout & Package

The SD2942W uses the M244 hermetically sealed, flanged, 4-lead balanced package (0.400″ × 0.860″), with metal base for direct thermal coupling to heatsinks. Leads are arranged in symmetrical source-drain-source-drain configuration for push-pull layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF1K50N and SD2932W, the SD2942W uniquely balances 350 W output, 0.35 °C/W thermal resistance, and 175 MHz impedance match in a field-proven M244 package-making it optimal for mid-power HF/VHF broadcast and industrial RF systems requiring reliability and serviceability.

Availability

SD2942W is available at Aetrix Electronics and suitable for FM broadcast transmitters, UHF TV exciters, avionics VHF comms, and industrial RF heating systems requiring stable component supply and long-lifecycle support.

Supply support for SD2942W 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 solutions for industrial, automotive, and communications markets.

The SD2942W belongs to ST's high-power RF MOSFET product line, engineered specifically for ruggedized HF/VHF/UHF amplifier applications demanding high efficiency, thermal robustness, and hermetic reliability in mission-critical infrastructure.

FAQ

What is the maximum continuous drain current rating for SD2942W?

The SD2942W is rated for 40 A continuous drain current at T_CASE = 25 °C. Derating is required above this temperature per the SOA curve in Figure 13; at 100 °C case temperature, maximum continuous I_D drops to approximately 22 A to maintain safe junction temperature.

Does SD2942W require external gate resistors for stability?

No external gate resistors are required for basic stability at 175 MHz, as confirmed by the production test circuit (Figure 16) and 5:1 VSWR tolerance. However, 10–22 Ω series gate resistors are recommended in high-dV/dt switching applications to suppress parasitic oscillation during transient events.

Can SD2942W be operated in Class C mode?

Yes-the SD2942W supports Class C operation with appropriate gate biasing and tuned output networks. Its low C_RSS (17 pF) and high transconductance enable efficient harmonic tuning, though efficiency and linearity trade-offs must be validated per application using the SOA and thermal models in Figures 13–15.

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

Yes-the SD2942W M244 package meets RoHS Directive 2011/65/EU and is lead-free. ST's ECOPACK® documentation confirms compliance, including exemption 7a for lead in high-melting-temperature solder alloys used in hermetic sealing. Full material declarations are available via ST's product change notifications.