STMicroelectronics L6494L

Overview

L6494L from STMicroelectronics is a high-voltage, single-chip half-bridge gate driver for N-channel MOSFETs and IGBTs, fabricated in BCD6 OFF-LINE technology. It delivers 2 A source / 2.5 A sink peak drive current, supports up to 600 V transient withstand voltage, features adjustable deadtime (0.34–6.0 μs), and integrates a bootstrap diode. It is used in motor control stages of industrial drives and UPS systems where high-side floating operation and robust dV/dt immunity (±50 V/ns) are required.

For engineers reviewing the L6494L datasheet, L6494L pinout, L6494L application, or L6494L equivalent, key selection considerations include its SO-14 package, dual UVLO protection (VCC and BOOT), TTL/CMOS-compatible 3.3 V/5 V inputs with hysteresis, and verified 85 ns propagation delay under 1 nF load.

Technical Context

The L6494L implements independent high-side (floating) and low-side driver sections, each with dedicated undervoltage lockout (UVLO) circuits referenced to SGND and OUT respectively. Its bootstrap driver replaces external fast-recovery diodes using an integrated DMOS structure with 175 Ω typical R_DS(on), enabling compact layout and reduced BOM count.

Logic control uses a single-phase input (IN) and active-low shutdown (SD), with deadtime programmable via an external resistor (R_DT) and capacitor (C_DT). The truth table confirms non-overlapping output behavior: HVG and LVG are never simultaneously high, preventing shoot-through in half-bridge topologies.

Key Specifications

Pinout & Package

Package: SO-14 (ECOPACK® compliant), 8.55–8.75 mm × 3.80–4.00 mm body, 1.27 mm pitch, thermal resistance R_thJA = 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 IR2110STRPBF and UCC27211D, the L6494L uniquely combines 600 V transient tolerance, integrated bootstrap diode, and resistor-programmable deadtime in a single SO-14 package - delivering superior layout simplicity and system-level reliability for industrial half-bridge designs.

Availability

L6494L is available at Aetrix Electronics and suitable for industrial motor drives, HID ballasts, induction heating systems, and UPS units requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L6494L 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, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The L6494L belongs to ST's high-voltage gate driver product line, engineered specifically for robust, compact half-bridge control in demanding industrial power conversion applications - emphasizing integration, reliability, and ease of use.

FAQ

What is the maximum recommended switching frequency for the L6494L?

The L6494L supports up to 800 kHz maximum switching frequency with a 1 nF capacitive load, as confirmed in the recommended operating conditions (Table 4). This limit assumes proper thermal management, adequate bootstrap capacitor sizing (e.g., ≥100 nF), and minimal PCB trace inductance. At higher frequencies, bootstrap recharge time and internal R_DS(on) voltage drop become critical - for example, a 30 nC gate charge with 5 μs charging time yields ~1 V drop across the integrated bootstrap DMOS.

How does the integrated bootstrap diode affect PCB layout compared to discrete solutions?

The integrated bootstrap diode eliminates the need for an external high-voltage fast-recovery diode, reducing component count, board area, and potential failure points due to diode leakage or reverse recovery. Layout benefits include simplified routing between BOOT and OUT pins, removal of high-dV/dt diode placement constraints, and elimination of associated decoupling and snubbing components - verified in ST's suggested SO-14 land pattern (Figure 7) and typical application diagram (Figure 6).

Can the L6494L drive IGBTs with gate-emitter thresholds above 5 V?

Yes - the L6494L's 2.5 A sink and 2 A source capability ensures strong Miller-effect immunity and rapid turn-on/turn-off for IGBTs with V_GE(th) up to 6 V. Its 15 V V_CC and V_BO operating range (9.3–20 V) provides sufficient gate drive voltage headroom. However, for IGBTs requiring >15 V gate drive, an external boost circuit on V_CC or BOOT is necessary, as the device's absolute maximum V_BOOT is 500 V DC and 620 V transient.

What happens if the DT pin is left floating or improperly biased?

The DT pin must be externally biased via resistor and capacitor to set deadtime; leaving it floating causes undefined deadtime behavior and may result in insufficient or excessive delay, risking shoot-through or reduced efficiency. The datasheet specifies minimum/maximum R_DT values (0–200 kΩ) and C_DT (100 nF) to ensure monotonic deadtime adjustment. An unconnected DT pin disables programmable deadtime functionality and may cause erratic output timing due to internal node instability.