STMicroelectronics SD3932

Overview

SD3932 from STMicroelectronics is an N-channel MOSFET RF power transistor in common-source push-pull configuration, rated for 100 V DC large-signal operation up to 250 MHz. It delivers ≥350 W output power with 26.8 dB gain and 66% drain efficiency at 123 MHz, housed in a thermally robust M244 epoxy-sealed package. It is used in HF/VHF/UHF broadcast amplifiers and industrial RF heating systems.

For engineers reviewing the SD3932 datasheet, SD3932 pinout, SD3932 application, or SD3932 equivalent, key selection criteria include its 250 V V(BR)DSS rating, 0.35 °C/W junction-to-case thermal resistance, 350 W CW P1dB performance at 123 MHz, and compatibility with 100 V supply rail RF amplifier designs.

Technical Context

The SD3932 is a dual-gate, push-pull configured RF power MOSFET optimized for Class AB or Class C operation in broadband HF–UHF amplifiers. Its static parameters include V(BR)DSS = 250 V, VGS(th) = 1.5–4.0 V, and RDS(on) ≤ 3.5 V at ID = 5 A, enabling stable high-voltage switching under large-signal drive.

Dynamically, it achieves 26.8 dB power gain and 66% drain efficiency at 350 W output into matched load at 123 MHz, with input/output impedance data (ZIN = 0.7 − j3.9 Ω, ZDL = 3.2 + j15 Ω) provided for matching network design. Load mismatch tolerance extends to 3:1 VSWR across all phase angles at 300 W output.

Key Specifications

Pinout & Package

The SD3932 is housed in the M244 plastic package: a 3-terminal, epoxy-sealed, flanged TO-style outline with copper baseplate for low-thermal-resistance mounting. Dimensions are 20.82 mm × 34.16 mm × 5.84 mm (L × W × H), with flange for mechanical and thermal interface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF158 and BLF278, the SD3932 uniquely balances 350 W CW output, 250 V breakdown, and 0.35 °C/W thermal resistance-making it optimal for thermally constrained, high-voltage HF/VHF amplifiers where both power density and reliability are critical.

Availability

SD3932 is available at Aetrix Electronics and suitable for broadcast transmitters, industrial RF heating systems, avionics HF amplifiers, and scientific plasma generators requiring stable component supply and long-lifecycle support.

Supply support for SD3932 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, designing and manufacturing analog, microcontroller, power, and RF devices for industrial, automotive, and communications markets.

The SD3932 belongs to ST's high-power RF MOSFET product line, engineered specifically for HF/VHF/UHF solid-state transmitter applications demanding high efficiency, thermal resilience, and broadband linearity.

FAQ

What is the recommended gate drive configuration for SD3932 in push-pull operation?

The SD3932 requires complementary, low-impedance gate drive with matched trace lengths and series gate resistors (typically 10–22 Ω) to ensure simultaneous turn-on/turn-off and minimize shoot-through current. ST Application Note AN2822 specifies use of transformer-coupled or complementary MOSFET drivers with <5 ns propagation delay skew between channels.

Can SD3932 operate reliably at 27.12 MHz with 500 W peak power?

No-its specified P1dB is ≥350 W CW at 123 MHz; while safe operating area (SOA) permits short pulses up to 800 W peak at 123 MHz, 27.12 MHz operation at 500 W exceeds its tested SOA envelope and risks thermal runaway due to reduced gain and increased conduction losses at lower frequencies.

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

Yes-the SD3932 is offered in ECOPACK®-compliant M244 packaging per STMicroelectronics' public product status documentation, meeting 2002/95/EC RoHS directive requirements with lead-free terminations and halogen-free epoxy molding compound.

What is the zero-temperature-coefficient (ZTC) point for SD3932, and why does it matter?

The ZTC point occurs at ~3.5 V VGS (per datasheet Figure 6), where transconductance drift vs. temperature crosses zero. This enables thermally stable Class AB biasing: fixed-VGS bias networks maintain quiescent current within ±10% over −55 °C to +125 °C, preventing thermal runaway in sealed enclosures.