STMicroelectronics L6388

Overview

L6388 from STMicroelectronics is a high-voltage, dual-channel gate driver IC designed to independently drive N-channel MOSFETs or IGBTs in half-bridge configurations. It features 600 V floating high-side capability, ±50 V/ns dV/dt immunity across –45°C to +125°C, 400 mA source / 650 mA sink output current, and integrated bootstrap diode for self-supplied high-side operation. It is used in industrial motor drives and SMPS inverters requiring robust shoot-through prevention.

For engineers reviewing the L6388 datasheet, L6388 pinout, L6388 application, or L6388 equivalent, key selection criteria include bootstrapped high-side voltage range (up to 618 V), interlocked logic inputs with 220–420 ns programmable dead time, TTL/CMOS-compatible 3.3 V/5 V/15 V inputs, and SO8/DIP8 package options with validated thermal resistance (100 °C/W for SO8).

Technical Context

The L6388 integrates two independent gate drivers - one low-side referenced to GND and one high-side referenced to a floating output node (OUT) - enabling direct control of high-side switches in bridge topologies. Its BCD "OFF-LINE" process supports 600 V rail operation while maintaining logic-level input compatibility and internal UV detection on both Vcc and Vboot rails.

It implements hardware-based interlocking and fixed dead-time insertion (220–420 ns) between HIN/LIN inputs to prevent simultaneous conduction. The patented internal bootstrap driver replaces external fast-recovery diodes using a synchronous DMOS+diode structure with 125 Ω typical R_DS(on), reducing leakage and board space in high-frequency (>400 kHz) applications.

Key Specifications

Pinout & Package

Available in SO8 (3.9 × 4.9 mm) and DIP8 (10.9 × 7.9 mm) packages. SO8 thermal resistance is 100 °C/W (junction-to-ambient); DIP8 is 150 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IR2110 and UCC27211, the L6388 uniquely combines integrated bootstrap diode, 600 V capability, and fixed dead-time interlock in a single SO8/DIP8 package-reducing component count and layout complexity for medium-frequency (<400 kHz), cost-sensitive industrial inverters.

Availability

L6388 is available at Aetrix Electronics and suitable for industrial motor drives, switch-mode power supplies, induction heating systems, and uninterruptible power supplies requiring stable component supply and long-term lifecycle support.

Supply support for L6388 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 ICs with vertical manufacturing and broad industrial qualification.

The L6388 belongs to ST's high-voltage gate driver product line, engineered specifically for cost-effective, robust half-bridge control in AC-DC and DC-AC conversion systems where bootstrap operation and shoot-through prevention are critical.

FAQ

What is the maximum recommended switching frequency for the L6388?

The L6388 is rated for up to 400 kHz under recommended operating conditions with a 1 nF load. At higher frequencies, bootstrap capacitor charging time and internal DMOS R_DS(on)-induced voltage drop must be carefully evaluated to maintain sufficient V_BS margin above the 8.2 V UV threshold.

Can the L6388 drive high-side P-channel MOSFETs?

No - the L6388 is designed exclusively for N-channel high-side and low-side MOSFETs or IGBTs. Its high-side output (HVG) is a source-follower referenced to the OUT pin and cannot provide the negative gate-source voltage required to fully enhance a P-channel device.

Is an external bootstrap diode ever required with the L6388?

Not under standard bootstrap operation where LVG on-time is sufficient to recharge C_BOOT. However, if V_OUT remains elevated for extended periods (e.g., >5 ms) or switching frequency is very low (<10 kHz), an external diode may be added to supplement charging and mitigate V_drop from the internal DMOS R_DS(on).

How does the interlock function behave when both HIN and LIN are high simultaneously?

When both inputs are high, the internal logic forces both LVG and HVG outputs low - effectively disabling both switches. This hard-wired interlock overrides input states and prevents shoot-through, independent of external timing or controller firmware behavior.