Fairchild Semiconductor's 650 V Green Mode Buck Switches Offer the Highest Power Efficiency with System Design Scalability

Fairchild FSL306 FSL336

Home appliance, industrial motor and smart meter applications require solutions that provide low standby power in order to achieve energy efficiency for the end user. At the same time, designers need power scalability to increase the power rating of a device for additional system functionality while simplifying designs. To meet this challenge, Fairchild Semiconductor developed the FSL306 and FSL336 650 V Green Mode AC Buck Switches.

Fairchild - FSL306, FSL336

These devices offer burst-mode operation with the low available operating current (250 µA) that helps to reduce standby mode power consumption for increased energy efficiency. Power scalability from 0.5 W to 3 W (FSL306) through the adjustable current limit pin helps simplify designs and reduce design time.

The FSL306 and FSL336 provide higher reliability through rich protection features, such as a Safe Auto Restart Mode. After a fault condition, the switch waits 650 ms before restarting. This feature reduces the stress on the system during a long-term fault, improving system reliability.

These devices combine a PWM controller and a discrete MOSFET in a single package. A high-voltage regulator enables operation without the need for an auxiliary bias winding. Using a built-in error amplifier, the FSL306 and FSL336 provide direct feedback without a shunt regulator. This helps to reduce the overall bill of material cost while saving board space.

Features and Benefits:

  • Built-in avalanche rated 650 V SenseFET; higher avalanche energy at breakdown mode due to vertical DMOS technology
  • Power scalability from 0.5 W to 3 W (FSL306) by using I limit adjustable function pin
  • No-load power consumption: 25 mW at 230 VAC with external bias; 120 mW at 230 VAC without external bias
  • No need for auxiliary bias winding
  • Ultra-low operating current – 250 µA – reduces standby power consumption
  • Fixed 650 ms restart time for safe auto-restart mode of all protection features

Price: in 1,000 quantity pieces:

  • FSL306LRN US $0.83
  • FSL336LR US $0.85

fairchildsemi.com