General description
The SSL4120 integrates a Power Factor Corrector (PFC) controller and a controller for a Half-Bridge resonant Converter (HBC) in a multi-chip IC. It provides the drive function for the discrete MOSFET in an up-converter and for the two discrete power MOSFETs in a resonant half-bridge configuration.

Features and benefits
General features
■ Integrated PFC and HBC controllers
■ Universal mains supply operation from 85 V to 305 V (AC)
■ High level of integration resulting in a low external component count and a cost
   effective design
■ Enable input to enable only the PFC or both the PFC and HBC controllers
■ On-chip high-voltage start-up source
■ Stand-alone operation or IC supplied from external DC source

PFC controller features
■ Boundary mode operation with on-time control
■ Valley/zero-voltage switching for minimum switching losses
■ Frequency limiting to reduce switching losses
■ Accurate boost voltage regulation
■ Burst mode switching with soft-start and soft-stop

HBC controller features
■ Integrated high-voltage level shifter
■ Adjustable minimum and maximum frequency
■ Maximum 500 kHz half-bridge switching frequency
■ Adaptive non-overlap time
■ Burst mode switching

Protection features
■ Safe restart mode for system fault conditions
■ General latched protection input for output overvoltage protection or external
   temperature protection
■ Protection timer for time-out and restart
■ Overtemperature protection
■ Soft (re)start for both controllers
■ Undervoltage protection for mains (brownout), boost, IC supply and output voltage
■ Overcurrent regulation and protection for both controllers
■ Accurate overvoltage protection for the boost voltage
■ Capacitive mode protection for the HBC controller

Applications
   The IC is used in all LED lighting applications that require very efficient, low Total
   Harmonic Distortion (THD), high Power Factor (PF) and a universal mains input voltage.
   The SSL4120 provides a cost-effective power supply solution between 25 W and 400 W.