L6599AD high-voltage resonant controller The L6599A is a double-ended controller specific to the series-resonant half-bridge topology. 

It provides 50% complementary duty cycle: the high-side switch and the low-side switch are driven ON/OFF 180° out-of-phase for exactly the same time. Output voltage regulation is obtained by modulating the operating frequency. A fixed deadtime inserted between the turn-off of one switch and the turn-on of the other guarantees soft-switching and enables high-frequency operation. To drive the high-side switch with the bootstrap approach, the IC incorporates a high-voltage floating structure able to withstand more than 600 V with a synchronous-driven high-voltage DMOS so that equivalent to the external fast-recovery bootstrap diode. The IC enables the designer to set the operating frequency range of the converter by means of an externally programmable oscillator. At startup, to prevent uncontrolled inrush current, the switching frequency starts from a programmable maximum value and progressively decays until it reaches the steady-state value determined by the control loop. IC functions include a not-latched active-low disable input with current hysteresis useful for power sequencing or for brownout protection, a current sense input for OCP with frequency shift and delayed shutdown with automatic restart. 

Features:

Up to 500 kHz operating frequency

Two-level OCP: frequency-shift and latched shutdown

Input for power-ON/OFF sequencing or brownout protection

Non-linear soft-start for monotonic output voltage rise

600 V-rail compatible high-side gate driver with integrated bootstrap diode and high dv/dt immunity

-300/800 mA high-side and low-side gate drivers with UVLO pull-down

SO16N package