Texas Instruments LMG3426R050RQZR

Overview

LMG3426R050 from Texas Instruments is a 600V, 50mΩ GaN FET with integrated gate driver, cycle-by-cycle overcurrent protection (<100ns response), zero-voltage detection (ZVD), and digital temperature PWM reporting. It operates from 7.5V–18V supply, supports up to 3.6MHz switching, and delivers 20–150V/ns adjustable slew rate for EMI-optimized hard-switching in high-density PSUs.

For engineers reviewing the LMG3426R050 datasheet, LMG3426R050 pinout, LMG3426R050 application, or LMG3426R050 equivalent, this page provides verified technical context, validated pin functions, confirmed ZVD timing behavior, real-world thermal PWM duty-cycle mapping, and two rigorously cross-checked alternative GaN FETs with documented functional distinctions.

Technical Context

The LMG3426R050 integrates a silicon-based gate driver with precision bias regulation, enabling robust 600V GaN-on-Si operation and 720V surge withstand during hard-switching. Its internal buck-boost converter generates VNEG for depletion-mode GaN turn-off control, while the RDRV pin sets slew rate via external resistor (0–500kΩ) to tune EMI and switching loss trade-offs.

ZVD functionality is exclusive to LMG3426R050 and outputs a 75–140ns pulse on the ZVD pin when zero-voltage switching is detected-triggered only after confirmed third-quadrant conduction (t3rd_ZVD = 42–56ns). Fault reporting includes push-pull OC, FAULT, and TEMP outputs with defined voltage thresholds and timing windows per JEDEC JEP180 compliance.

Key Specifications

Pinout & Package

The LMG3426R050 uses a 54-pin VQFN package (RQZ), 12.00 mm × 12.00 mm, with exposed thermal pad internally connected to SOURCE, GND, and NC2 pins. The package supports high-current routing and low-inductance layout essential for GaN switching integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar GaN FET applications.

Compared with LMG3427R050, LMG3426R050 provides unique ZVD timing for resonant control but lacks ZCD; compared with GS66508T, it trades external design flexibility for integrated protection, temperature telemetry, and reduced system-level component count.

Availability

LMG3426R050 is available at Aetrix Electronics and suitable for server PSU, telecom rectifier, and solar inverter designs requiring stable component supply, long-term lifecycle support, and JEDEC JEP180-qualified GaN reliability.

Supply support for LMG3426R050 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

Texas Instruments is a global semiconductor leader focused on analog and embedded processing technologies, with decades of power management innovation and automotive-grade quality systems.

The LMG342xR050 family was designed specifically for high-frequency, high-density switch-mode power conversion-targeting merchant PSUs, telecom infrastructure, and renewable energy inverters where GaN's speed and efficiency deliver measurable system-level advantages.

FAQ

What is the function of the ZVD pin on the LMG3426R050?

The ZVD pin on the LMG3426R050 outputs a 75–140 ns pulse when zero-voltage switching is detected, with a 15–30 ns delay from the IN rising edge. This hardware-accelerated signal enables precise adaptive dead-time control in resonant topologies. Unlike software-based detection, ZVD operates independently of controller latency-ensuring reliable ZVS across line/load transients. The LMG3426R050 is the only variant in the LMG342xR050 family with ZVD functionality.

How does the RDRV pin adjust slew rate on the LMG3426R050?

The RDRV pin on the LMG3426R050 sets gate drive strength by connecting an external resistor to GND: 0 Ω yields 150 V/ns, 300 kΩ yields 20 V/ns, and connection to LDO5V yields 100 V/ns. This resistor directly controls internal current sources driving the GaN gate, allowing EMI optimization without altering gate resistance or layout. The LMG3426R050 datasheet provides measured slew rate vs RDRV curves across temperature and bus voltage.

What does the TEMP pin output represent on the LMG3426R050?

The TEMP pin on the LMG3426R050 outputs a fixed 9 kHz PWM signal whose duty cycle encodes junction temperature: 0.3–6% at 25°C, 36.2–43.7% at 85°C, and 58.5–70% at 125°C. This eliminates need for external thermistors or signal conditioning. The LMG3426R050's on-die thermal sensor is factory-trimmed and calibrated-delivering ±3°C accuracy across its −40°C to 150°C operating range without host MCU firmware calibration.

Does the LMG3426R050 require an external bootstrap capacitor?

No-the LMG3426R050 integrates a buck-boost converter that generates VNEG (−14 V typical) for GaN turn-off, eliminating external bootstrap components. The BBSW pin connects to an external inductor (3–10 µH), and VNEG must be bypassed with a 2.2 µF capacitor. This architecture avoids bootstrap diode drop, timing drift, and voltage starvation issues common in high-duty-cycle or high-frequency half-bridge designs using the LMG3426R050.

What protection features are implemented in hardware on the LMG3426R050?

The LMG3426R050 implements five hardware-protected fault conditions: overcurrent (OC), short-circuit (SC), overtemperature (OTP), VDD UVLO, and VNEG UVLO-all with dedicated comparators and <100 ns response for OC/SC. Faults are reported on FAULT (latched) and OC (cycle-by-cycle) pins. These protections operate autonomously without MCU intervention, ensuring fail-safe operation even during controller reset or communication loss-critical for mission-critical power systems using the LMG3426R050.