STMicroelectronics L6494LD

Overview

L6494LD from STMicroelectronics is a high-voltage half-bridge gate driver IC for N-channel MOSFETs and IGBTs, fabricated in BCD6 OFF-LINE technology. It delivers 2 A source / 2.5 A sink peak current, supports 600 V transient withstand voltage, features adjustable deadtime (0.34–6.0 μs), and integrates a bootstrap diode. It is used in motor drives for industrial automation and UPS systems.

For engineers reviewing the L6494LD datasheet, L6494LD pinout, L6494LD application, or L6494LD equivalent, key selection criteria include dV/dt immunity (±50 V/ns), dual UVLO protection (VCC and BOOT), TTL/CMOS-compatible 3.3 V/5 V inputs with hysteresis, SO-14 package layout simplicity, and bootstrap diode integration for reduced BOM count.

Technical Context

The L6494LD implements a single-input, active-low shutdown architecture with independent high-side (floating) and low-side driver sections. Its high-side section operates up to 500 V DC with 600 V transient capability, while the low-side section accepts VCC from 10–20 V. Both sections feature undervoltage lockout (UVLO) with hysteresis-VCC UVLO thresholds at 8.7 V (ON) / 8.2 V (OFF), and BOOT UVLO at 8.6 V (ON) / 8.0 V (OFF).

Deadtime is externally programmable via a resistor (RDT) and capacitor (CDT), enabling precise control over cross-conduction prevention. Propagation delay is tightly matched at 85 ns typ. (turn-on/off), with rise/fall times of 25 ns into 1 nF load. The integrated bootstrap DMOS (RDS(on) = 175 Ω typ.) replaces external fast-recovery diodes, reducing leakage and PCB area.

Key Specifications

Pinout & Package

Package: SO-14 (ECOPACK® compliant, surface-mount, 8.55 × 3.80 mm footprint). Thermal resistance R_th(JA) = 120 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRS21844STRPBF and UCC27211D, the L6494LD uniquely combines 600 V transient tolerance, integrated bootstrap diode, and SO-14 compactness-making it optimal for cost-sensitive, space-constrained 400–600 V industrial half-bridge designs where BOM reduction and layout simplicity are prioritized over ultra-high peak current.

Availability

L6494LD is available at Aetrix Electronics and suitable for industrial motor drives, HID lighting ballasts, induction heating systems, and UPS inverters requiring stable component supply across extended production lifecycles.

Supply support for L6494LD 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 microcontroller technologies for industrial, automotive, and consumer markets.

The L6494LD belongs to ST's high-voltage gate driver product line, designed specifically for robust, compact, and cost-effective half-bridge control in industrial power conversion systems operating up to 600 V.

FAQ

What is the maximum recommended switching frequency for the L6494LD?

The L6494LD supports up to 800 kHz maximum switching frequency when driving a 1 nF capacitive load, as specified in the recommended operating conditions. This limit assumes proper PCB layout, adequate bootstrap capacitor sizing (e.g., ≥100 nF for typical gate charges), and thermal management to maintain junction temperature ≤125 °C. At higher frequencies, bootstrap voltage droop and propagation delay matching become critical design constraints.

Can the L6494LD drive SiC MOSFETs effectively?

Yes-the L6494LD's 2.5 A sink / 2 A source peak current, 25 ns rise/fall times into 1 nF, and ±50 V/ns dV/dt immunity make it suitable for driving medium-gate-charge SiC MOSFETs (e.g., ≤35 nC) in 400–600 V applications. However, designers must verify gate resistor selection to control dv/dt and ensure bootstrap capacitor recharge time exceeds the low-side on-time at minimum duty cycle.

How does the integrated bootstrap DMOS affect efficiency compared to an external diode?

The integrated DMOS introduces ~175 Ω on-resistance, causing a voltage drop (V_drop = Q_gate/t_charge × 175 Ω) during bootstrap capacitor recharge. At high frequencies or long low-side on-times, this can reduce effective BOOT voltage. However, its leakage is <8 μA-significantly lower than typical 600 V external diodes (≥100 μA)-improving light-load efficiency and thermal stability in continuous conduction mode.

Is the L6494LD pin-compatible with earlier revisions like L6494D?

No-the L6494LD is not pin-compatible with legacy L6494D variants. While both use SO-14 packages, the L6494LD features updated electrical characteristics (e.g., revised deadtime ranges, tighter quiescent current specs per Rev 3 datasheet) and improved thermal performance. Pin mapping remains identical, but system-level validation-including timing margins, UVLO behavior, and bootstrap recharge dynamics-is required before substitution.