MT79398 is a single-stage, primary side control AC-DC IC for LED driver with active power factor correction. The chip integrates on-chip PFC circuit which operates under critical conduction mode (CRM) to achieve high power factor and reduces the power MOSFET switching loss. With innovative control technique, precision LED current is achieved without secondary side sense and feedback circuit including opto-coupler. 

MT79398 integrates 700V power MOSFET, the peripheral circuit is simplified. 

MT79398 provides various protections, such as input over/under-voltage protection, over-current protection (OCP), output over-voltage protection (OVP), short-circuit protection (SCP) and over-temperature regulation (OTR) etc., to improve system reliability. Moreover, the chip is designed with thermal regulation setting pin TADJ, which allows flexible setting of the thermal regulation threshold by connecting an external resistor to ground. 

• Single-stage active PFC for high power factor 

• Internal integrator (no external COMP capacitor) 

• Internal THD compensation circuit 

• Internal line regulation 

• Primary side control saving opto-coupler 

• High precision LED current: ±2% 

• Operates under CRM 

• Cycle-by-cycle current limiting 

• Embedded with 700V power MOSFET 

• Various protections with self-recovery

?Input over/under-voltage protection 

?Over-current protection 

?Output over-voltage/open-circuit protection 

?Short-circuit protection 

• Flexibly set thermal regulation threshold through TADJ 

• Power on soft-start 

• Available in DIP8 packages