STMicroelectronics L6569

Overview

L6569 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 600V high-side rail capability, internal bootstrap diode structure, 15.6V zener clamp on VS, 1.25µs typical dead time, and programmable oscillator frequency up to 200kHz.

For engineers reviewing the L6569 datasheet, L6569 pinout, L6569 application, or L6569 equivalent, key selection considerations include its BCD off-line technology, dV/dt immunity (±50V/ns), sink/source drive strength (270mA/170mA), under-voltage lockout with hysteresis, and bootstrap LDMOS R_ON of 120Ω - all critical for reliable high-voltage half-bridge control in CFL and HID lighting systems.

Technical Context

The L6569 integrates a programmable RC oscillator (f_OSC = 1.3863/(R_FC_F)), level-shifting circuitry for high-side gate drive, and patented internal bootstrap charge pump synchronized with LVG output via 50ns delay. Its logic bias regulator and comparator-based UVLO (9V turn-on, 8V turn-off, 1V hysteresis) ensure robust startup under varying line conditions.

It implements cross-conduction prevention through fixed internal dead time (0.85–1.65µs), supports external logic override via CF pin, and provides dV/dt-immune high-side driver operation up to ±50V/ns on BOOT and OUT pins - enabling stable operation in noisy high-dV/dt switching environments like electronic ballasts.

Key Specifications

Pinout & Package

Available in SO8 (small outline 8-pin) and Minidip packages. SO8 meets JEDEC MS-012AC standard (D = 4.8–5.0mm, E = 5.8–6.2mm, e = 1.27mm pitch); Minidip is through-hole compatible (D = 10.92mm, E = 7.95–9.75mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with IR2153 and IRS21531, the L6569 uniquely combines VS zener clamping, internal bootstrap LDMOS (R_ON = 120Ω), and guaranteed ±50V/ns dV/dt immunity - making it especially robust for unregulated, high-dV/dt lamp ballast applications where supply transients and noise are prevalent.

Availability

L6569 is available at Aetrix Electronics and suitable for compact fluorescent lamp ballasts, HID electronic ballasts, resonant switch-mode power supplies, and induction heating half-bridge drivers requiring stable component supply and long-term industrial availability.

Supply support for L6569 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, microcontrollers, and automotive ICs.

The L6569 belongs to ST's high-voltage analog driver product line, engineered specifically for energy-efficient lighting control and resonant power conversion - emphasizing integration, reliability, and ease of use in cost-sensitive consumer and industrial lighting systems.

FAQ

What is the difference between L6569 and L6569A?

The L6569A modifies the bootstrap startup sequence: it holds the low-side driver (LVG) off until the VS supply reaches the UVLO turn-on threshold (9V), then initiates bootstrap capacitor charging. The standard L6569 begins charging immediately after power-up, which may cause premature high-side conduction. This change improves safety during cold-start preheat in CFL applications.

Can L6569 drive IGBTs directly?

Yes - the L6569 is explicitly rated to drive both n-channel MOSFETs and IGBTs. Its 270mA sink / 170mA source output current, 600V V_BOOT rating, and ±50V/ns dV/dt immunity meet the gate-drive requirements of common 500V–600V IGBTs used in ballast and SMPS half-bridges, provided gate resistor values are selected to limit peak current within spec.

How is oscillator frequency set, and what is the minimum/maximum range?

Oscillator frequency is set by external resistor RF (pin 2) and capacitor CF (pin 3) using f_OSC = 1.3863/(R_FC_F). With RF = 12kΩ and CF = 1nF, f_OSC = 60kHz. The datasheet confirms operation up to 200kHz; practical minimum is ~20kHz (limited by CF leakage and timing accuracy), and maximum is constrained by internal propagation delays and driver slew rate.

Is an external bootstrap diode required?

No - the L6569 incorporates a patented internal bootstrap driver using a high-voltage lateral DMOS (R_ON = 120Ω) and synchronized charge pump, eliminating the need for an external bootstrap diode. This reduces component count, PCB area, and failure modes associated with diode reverse recovery and thermal stress in high-temperature lamp ballast environments.