STMicroelectronics L6384D

Overview

L6384D from STMicroelectronics is a high-voltage half-bridge gate driver IC designed to control N-channel power MOSFETs and IGBTs in off-line switching applications. It features 600 V rail capability, ±50 V/ns dV/dt immunity across −45 °C to +125 °C, 400 mA source / 650 mA sink output drive, 50 ns rise / 30 ns fall times (1 nF load), and integrated bootstrap driver replacing external diodes - used in AC-DC SMPS and motor inverters.

For engineers reviewing the L6384D datasheet, L6384D pinout, L6384D application, or L6384D equivalent, key selection considerations include floating high-side operation up to 600 V, programmable dead time via external resistor (0.4–3.1 µs), UVLO thresholds (12 V turn-on / 10 V turn-off), CMOS/TTL Schmitt-trigger inputs with hysteresis, and SO8 package thermal resistance of 150 °C/W.

Technical Context

The L6384D implements a BCD "off-line" process-based half-bridge architecture with independent high-side (HVG) and low-side (LVG) drivers referenced to Vout and GND respectively. Its level-shifting circuitry enables reliable high-side switching at up to 600 V, while matched propagation delays (ton/tonsd/toff ≤ 300 ns) support stable operation up to 400 kHz.

Dead time is set externally via resistor Rdt on pin 3 (DT/SD), generating 0.4–3.1 µs delay depending on value (47–270 kΩ); shutdown is activated when pin 3 voltage drops below 0.5 V. The integrated bootstrap driver - comprising a synchronous DMOS switch and series diode - eliminates need for external fast-recovery diode but requires sufficient LVG-on time for CBOOT recharge.

Key Specifications

Pinout & Package

Package: SO8 (Small Outline, 8-pin), 150 °C/W junction-to-ambient thermal resistance, 3.9 mm × 4.9 mm body size, 1.27 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar half-bridge gate driver applications.

Compared with IR2104S and UCC27201D, the L6384D uniquely combines 600 V capability, integrated bootstrap driver, and programmable dead time in SO8 - making it optimal for compact, high-reliability off-line converters where external diode elimination and noise immunity are critical.

Availability

L6384D is available at Aetrix Electronics and suitable for AC-DC power supplies, BLDC motor inverters, and PFC circuits requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for L6384D 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, MCU, and automotive-grade ICs with vertical manufacturing and broad industrial qualification.

The L6384D belongs to ST's high-voltage gate driver product line, engineered specifically for off-line SMPS, motor control, and industrial power conversion where robustness, integration, and 600 V operation are mandatory.

FAQ

What is the maximum allowable bootstrap capacitor discharge voltage drop for reliable L6384D operation?

The L6384D requires Vboot ≥ 17 V above Vout to sustain high-side drive. With typical Rdson = 125 Ω and Qgate = 30 nC, a 5 µs LVG-on time yields ~0.8 V drop. Total CBOOT voltage drop must therefore stay below ~2.5 V to maintain ≥17 V margin - achieved using CBOOT ≥ 100 nF for Qgate ≤ 30 nC and Tcharge ≥ 5 µs.

Can pin 3 (DT/SD) be left unconnected or tied directly to Vcc?

No - pin 3 must never be left floating or pulled directly to Vcc. Its high-impedance nature makes it susceptible to noise-induced shutdown. Connect a resistor (47–270 kΩ) between pin 3 and GND for dead time setting, or pull it below 0.5 V for shutdown. Long PCB traces or low-impedance Vcc ties cause erroneous behavior due to internal current-source loading.

Does the L6384D support 100% duty cycle high-side operation?

No - the integrated bootstrap driver requires periodic LVG conduction to recharge CBOOT. Continuous high-side conduction depletes Vboot, causing undervoltage lockout. For 100% duty cycle, an external isolated supply or charge pump is required; the L6384D is optimized for typical half-bridge duty cycles ≤95%.

How does the L6384D's dV/dt immunity compare to standard gate drivers in motor drive applications?

The L6384D guarantees ±50 V/ns dV/dt immunity across its full operating temperature range (−45 °C to +125 °C), exceeding most competitors (e.g., IR2104: ±25 V/ns, UCC27201: ±30 V/ns). This allows direct use in high-noise BLDC inverters without additional filtering, reducing BOM count and improving system reliability under fast-switching transients.