STMicroelectronics L6387

Overview

L6387 from STMicroelectronics is a high-voltage, dual-channel gate driver IC designed to independently drive N-channel power MOSFETs or IGBTs in half-bridge configurations. 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 current, and 50/30 ns rise/fall times into 1 nF load - enabling robust motor control and SMPS applications.

For engineers reviewing the L6387 datasheet, L6387 pinout, L6387 application, or L6387 equivalent, key selection criteria include bootstrap-integrated high-side drive, interlocked logic inputs to prevent shoot-through, UVLO thresholds (6.0 V turn-on, 5.5 V turn-off), and SO8 Minidip package thermal resistance (100 °C/W).

Technical Context

The L6387 integrates a patented internal bootstrap DMOS structure with series diode and charge pump, eliminating the need for an external fast-recovery bootstrap diode. Its level-shifter enables floating high-side operation up to 600 V with guaranteed −3 V to 580 V output swing under V_boot–V_out < 18 V condition.

Interlocked CMOS/TTL-compatible inputs enforce mutually exclusive HVG/LVG activation per truth table (HIN=1,LIN=0 → HVG=1; HIN=0,LIN=1 → LVG=1), preventing simultaneous conduction. Propagation delays are 110 ns (turn-on) and 105 ns (turn-off) at V_cc=15 V, T_j=25°C, with temperature-stable performance up to 125°C junction.

Key Specifications

Pinout & Package

Package: SO8 Minidip (body size 5.0 mm × 6.2 mm, lead pitch 1.27 mm, R_{th j-amb} = 100 °C/W). Pinout validated per official STMicroelectronics datasheet (Rev. 9, May 2001).

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 L6387 uniquely combines integrated bootstrap, interlocked logic, and 600 V capability in SO8 - reducing component count and layout complexity for cost-sensitive industrial inverters.

Availability

L6387 is available at Aetrix Electronics and suitable for industrial motor drives, switch-mode power supplies, induction cooking systems, and uninterruptible power supplies requiring stable component supply and long-term obsolescence management.

Supply support for L6387 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 automotive, industrial, and power discrete solutions with vertical manufacturing capabilities.

The L6387 belongs to ST's high-voltage gate driver product line, engineered specifically for reliable half-bridge control in AC-DC and DC-AC conversion systems operating up to 600 V bus voltages.

FAQ

What is the maximum allowable V_BOOT–V_OUT differential for continuous operation?

The L6387 specifies a maximum V_BOOT–V_OUT differential of 18 V for guaranteed operation. Exceeding this causes V_OUT to be clamped at 580 V. This constraint arises from internal level-shifter voltage limits and must be respected in bootstrap capacitor sizing and topology selection - especially in high-duty-cycle or low-frequency applications where C_BOOT discharge is significant.

Can the L6387 drive IGBTs with gate-emitter threshold voltages above 5 V?

Yes - the L6387 delivers 15 V gate drive (V_CC-referenced for LVG, V_BOOT-referenced for HVG), sufficient for standard 5–6 V IGBTs. Its 650 mA sink current ensures rapid turn-off even with high Miller capacitance. However, for IGBTs requiring >15 V gate drive or active Miller clamping, external gate driver augmentation is required, as the L6387 does not support programmable output voltage.

How does the internal bootstrap DMOS affect minimum duty cycle requirements?

The internal bootstrap DMOS requires sufficient low-side conduction time (LVG ON) to recharge C_BOOT. Minimum duty cycle depends on gate charge (Q_g), C_BOOT value, and Rdson (125 Ω). For example, with Q_g=30 nC and C_BOOT=100 nF, ≥5 µs LVG ON time is needed to limit V_BOOT droop to <1 V. Below this, high-side drive may collapse due to insufficient bootstrap voltage.

Is the L6387 pin-compatible with newer ST gate drivers like the STGAP2S?

No - the L6387 uses an 8-pin SO8 Minidip footprint with specific pin assignments (e.g., V_OUT on pin 6, V_BOOT on pin 8), while STGAP2S is a 16-pin SOIC with isolated outputs, different UVLO thresholds, and no integrated bootstrap. Migration requires PCB redesign and firmware adaptation due to fundamental architecture differences in isolation, drive strength, and protection features.