LinkSwitch-4 controllers feature an adaptive base and emitter switched drive scheme to boost switching performance and increase efficiency. The advanced switching technique is especially beneficial in high-voltage applications as it reduces slow turn-off switching losses and eliminates BJT failures due to secondary breakdown, improving the reverse-bias safe operating area and system reliability.
The LinkSwitch-4 controllers’ primary-side regulated sensing methodology eliminates expensive and unreliable optocouplers, replacing them in the feedback loop with a simple transformer winding. The design uses just 50mW under no-load conditions while maintaining a fast transient response.
The 65kHz operating frequency minimises transformer size, reducing system cost and PCB footprint. The controller devices also compensate for a number of factors including: transformer inductance tolerances, input line voltage variations, cable voltage drop, and external component temperature variations.