STMicroelectronics L6569A

Overview

L6569A from STMicroelectronics is a high-voltage half-bridge gate driver IC with integrated oscillator, designed for driving external n-channel MOSFETs and IGBTs in resonant lamp ballast and SMPS applications. It features programmable oscillator frequency (up to 200 kHz), 1.25 µs typical dead time, internal bootstrap diode structure, and 15.6 V zener clamp on VS pin. Operates with floating supply up to 618 V and supports dV/dt immunity up to ±50 V/ns.

For engineers reviewing the L6569A datasheet, L6569A pinout, L6569A application in CFL ballasts or resonant converters, or L6569A equivalent for half-bridge gate drive solutions, this page delivers verified electrical parameters, startup behavior differentiation vs. L6569, SO8 package details, and real-world design constraints including BOOT pin safe operating area and UVLO hysteresis.

Technical Context

The L6569A integrates a programmable RC oscillator, level-shifting circuitry, and dual gate drivers with built-in dead-time control (1.25 µs typ.) to prevent cross-conduction. Its patented internal bootstrap structure replaces the external diode by using a 120 Ω R_ON LDMOS switch synchronized to LVG with 50 ns delay.

Unlike the L6569, the L6569A delays low-side turn-on until VS exceeds the UVLO threshold (9 V typ.), then initiates bootstrap capacitor charging after a fixed delay - eliminating premature conduction during brown-in conditions. This ensures reliable startup under low-line or soft-start scenarios.

Key Specifications

Pinout & Package

Package: SO8 (Small Outline, 8-pin, 1.27 mm pitch), compliant with JEDEC MS-012, thermal resistance R_{th j-amb} = 150 °C/W (SO8).

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRS2153D and UCC27712, the L6569A uniquely combines oscillator integration, bootstrap diode elimination, and differentiated startup - making it optimal for compact, self-contained resonant lamp ballasts where BOM reduction and reliable low-line startup are mandatory.

Availability

L6569A is available at Aetrix Electronics and suitable for compact fluorescent lamp ballasts, resonant half-bridge SMPS, LED drivers with resonant topology, and induction heating half-bridge circuits requiring stable component supply and long-term lifecycle support.

Supply support for L6569A 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, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The L6569A belongs to ST's AC-DC and lighting control product line, engineered specifically for energy-efficient electronic ballasts and resonant converters requiring integrated timing, robust gate drive, and simplified high-voltage bootstrap implementation.

FAQ

What is the key functional difference between L6569 and L6569A?

The L6569A implements a delayed low-side startup sequence: it holds LVG low until VS rises above the UVLO turn-on threshold (9 V typ.), then initiates bootstrap capacitor charging. In contrast, the L6569 begins charging immediately upon power application, risking premature conduction and shoot-through during brown-in conditions. This makes L6569A more robust in universal-input lamp ballasts.

Can the L6569A drive IGBTs directly?

Yes - the L6569A's 270 mA sink and 170 mA source capability meets gate drive requirements for typical 12–25 A IGBTs used in resonant ballasts and SMPS. Its 1.25 µs dead time prevents cross-conduction, and its ±50 V/ns dV/dt immunity ensures reliable operation even with fast IGBT switching edges and high dv/dt noise.

How does the internal bootstrap structure work without an external diode?

The L6569A uses a patented high-voltage LDMOS (R_ON = 120 Ω) switched synchronously with LVG, acting as a synchronous rectifier to charge the bootstrap capacitor. It turns on ~50 ns after LVG goes high, closing the charging path through the conducting low-side MOSFET - eliminating reverse-recovery loss and reliability concerns associated with discrete bootstrap diodes.

Is the L6569A pin-compatible with the L6569?

Yes - both L6569 and L6569A share identical SO8 pinout, absolute maximum ratings, oscillator programming interface, and gate drive specifications. The only difference is internal startup sequencing; no PCB or schematic changes are needed when upgrading from L6569 to L6569A for improved low-line robustness.