STMicroelectronics L6599AN

Overview

L6599AN from STMicroelectronics is a high-voltage double-ended resonant half-bridge controller IC with 50% complementary duty cycle, variable-frequency control up to 500 kHz, integrated 600 V-compatible high-side gate driver with synchronous bootstrap diode, and dual-level overcurrent protection (frequency-shift + latched shutdown). It regulates output voltage by modulating switching frequency in LLC and series-resonant SMPS for LCD/PDP TVs and telecom power supplies.

For engineers reviewing the L6599AN datasheet, L6599AN pinout, L6599AN application, or L6599AN equivalent, key selection criteria include its 600 V rail compatibility, non-linear soft-start behavior, burst-mode operation at light load, and PFC interface capability - all critical for high-efficiency AC-DC adapter and open-frame SMPS designs.

Technical Context

The L6599AN implements a relaxation oscillator with externally programmable minimum frequency (via RFmin pin reference of 2.0 V ±3%) and timing capacitor (CF), enabling precise frequency modulation for output regulation. Its fixed deadtime (0.2–0.4 µs) ensures zero-voltage switching in resonant topologies.

It integrates two independent overcurrent protections: first-level frequency shift triggered at 0.8 V on ISEN with 50 mV hysteresis, and second-level latched shutdown at 1.5 V; both are validated across –40°C to +105°C junction temperature range per datasheet Table 5.

Key Specifications

Pinout & Package

Package: DIP16 (dual in-line package, 16-pin, through-hole mounting, 80 °C/W junction-to-ambient thermal resistance).

Key Features

Applications

Equivalent & Alternatives

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

Compared with UCC256301 and IR3584M, the L6599AN delivers a fully integrated analog solution with embedded 600 V bootstrap, LINE/brownout input, and PFC coordination - reducing external component count by ≥7 parts while maintaining design simplicity for proven resonant topologies.

Availability

L6599AN is available at Aetrix Electronics and suitable for LCD/PDP TV power supplies, telecom SMPS, and AC-DC adapters requiring stable component supply, long-term lifecycle support, and RoHS-compliant through-hole packaging.

Supply support for L6599AN 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, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The L6599AN belongs to ST's high-voltage resonant controller product line, engineered specifically for reliable, high-efficiency LLC and series-resonant half-bridge SMPS in cost-sensitive, high-volume power conversion applications.

FAQ

What is the maximum operating frequency and how is it set?

The L6599AN supports up to 500 kHz operation, determined by the external timing components CF (capacitor on pin 3) and RFmin (resistor on pin 4). The oscillator frequency is programmable via the current mirror ratio and CF value, with typical range 58–62 kHz at RRFmin = 12 kΩ and CF = 470 pF, scalable to 500 kHz using smaller RFmin and CF values per Figure 9 in the datasheet.

Does the L6599AN require an external bootstrap diode?

No. The L6599AN integrates a patented synchronous bootstrap diode driven in-phase with the LVG signal, eliminating the need for an external fast-recovery diode. This structure feeds the VBOOT capacitor directly and is rated for 600 V rail operation, improving reliability and reducing board space in high-voltage half-bridge designs.

How does the two-level overcurrent protection work?

Level 1 triggers at 0.8 V on ISEN (50 mV hysteresis), initiating frequency shift to limit power; level 2 latches off the IC at 1.5 V on ISEN. The DELAY pin adds programmable hold-off time before latching, allowing temporary overloads without shutdown - validated across –40°C to +105°C per Table 5 electrical characteristics.

Can the L6599AN interface with a PFC controller?

Yes. Pin 9 (PFC_STOP) is an open-drain output that pulls low during DIS activation, ISEN latched shutdown, LINE overvoltage (>6 V), or STBY-triggered burst mode. It directly interfaces with standard PFC controllers (e.g., L6562A, UCC28070) to disable the pre-regulator during faults, ensuring system-level protection coordination.