STMicroelectronics L6491DTR

Overview

L6491DTR from STMicroelectronics is a high-voltage, single-chip half-bridge gate driver for N-channel MOSFETs and IGBTs, featuring 4 A source/sink peak current, ±50 V/ns dV/dt immunity, and integrated bootstrap diode. It supports up to 600 V rail voltage, operates with 3.3 V/5 V TTL/CMOS logic inputs, and delivers 15 ns rise/fall times into 1 nF load - enabling robust motor control in industrial inverters and induction heating systems.

For engineers reviewing the L6491DTR datasheet, L6491DTR pinout, L6491DTR application, or L6491DTR equivalent, this device is selected for high-reliability half-bridge switching where fast fault response, adjustable deadtime, interlocking, and smart shutdown are critical in high-noise, high-voltage environments.

Technical Context

The L6491DTR integrates independent high-side (floating) and low-side driver sections using BCD6 "OFF-LINE" technology, with V_BOOT operating up to 620 V and V_OUT supporting DC output voltages up to 580 V. Its comparator-based fault protection triggers within 175–220 ns of overcurrent detection, directly forcing both outputs low without external latch dependency.

Deadtime is programmable via an external resistor (0.12–3 µs range) and synchronized with interlocking logic to prevent shoot-through; the smart shutdown function provides immediate gate turn-off upon comparator trip while maintaining open-drain SD/OD latching until V_SSD (0.8 V) is reached - decoupling protection timing from RC network delays.

Key Specifications

Pinout & Package

Package: SO-14 (ECOPACK® compliant), surface-mount, 8.55–8.75 mm × 3.80–4.00 mm body, 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IR2110STRPBF and UCC27211D, the L6491DTR uniquely combines integrated bootstrap, comparator-based fault response, and programmable hardware deadtime - reducing design cycle time and PCB area in high-reliability industrial and appliance inverters.

Availability

L6491DTR is available at Aetrix Electronics and suitable for industrial motor drives, induction heating systems, HID ballasts, and wireless power transmitters requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L6491DTR 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, mixed-signal, power, and microcontroller solutions for industrial, automotive, and consumer markets.

The L6491DTR belongs to ST's high-voltage gate driver product line, engineered specifically for robust half-bridge control in harsh EMI environments - targeting motor control, lighting, and resonant power conversion applications demanding reliability and integration.

FAQ

What is the maximum allowable bootstrap capacitor voltage (V_BOOT) for L6491DTR?

The absolute maximum V_BOOT is 620 V, referenced to V_OUT. This rating enables safe operation with 600 V rail voltages in industrial inverters and UPS systems. Exceeding this voltage risks permanent damage to the internal bootstrap DMOS structure, as confirmed in Table 3 of DS9763 Rev 2. Designers must ensure V_BOOT − V_OUT stays within –0.3 V to +0.3 V during transients.

How does the smart shutdown function differ from standard shutdown behavior?

Smart shutdown bypasses the SD input logic path: upon comparator trigger, outputs turn off within 175–220 ns regardless of SD pin voltage, while the SD/OD pin latches low until V_SD drops below 0.8 V. Standard shutdown only responds to SD pin transitions. This architecture eliminates RC timing dependency and guarantees fastest possible fault response, as detailed in Section 7 of DS9763.

Can L6491DTR drive SiC MOSFETs effectively?

Yes - its 4 A peak current, 15 ns switching times, and ±50 V/ns dV/dt immunity meet key requirements for discrete SiC MOSFET gate driving. However, designers must verify gate resistor selection and C_BOOT sizing against the specific SiC device's Q_g and switching frequency, as the internal bootstrap DMOS R_DS(on) (175 Ω) introduces voltage drop during high-frequency recharge cycles.

Is an external bootstrap diode ever required with L6491DTR?

An external diode is optional but recommended when V_OUT remains near or above SGND for extended periods (e.g., in high-duty-cycle topologies), or when C_BOOT recharge time is insufficient due to short LVG-on duration. The internal DMOS bootstrap works reliably only when LVG is actively driven low long enough to charge C_BOOT, per Section 9 of DS9763.