The TOP254EN is an enhanced EcoSmart™ Integrated Offline Switcher with advanced feature set and extended power range. TOPSwitch-HX incorporates a 700V power MOSFET and high voltage switched current source, PWM control, oscillator, thermal shutdown circuit, fault protection and other control circuitry onto a monolithic device. TOPSwitch-HX is an integrated switched mode power supply chip that converts a current at the control input to a duty cycle at the open drain output of a high voltage power MOSFET. It features the high voltage start-up, the cycle-by-cycle current limiting, loop compensation circuitry, auto-restart and thermal shutdown, the TOPSwitch-HX incorporates many additional functions that reduce system cost, increase power supply performance and design flexibility. A patented high voltage CMOS technology allows both the high-voltage power MOSFET and all the low voltage control circuitry to be effectively integrated onto a single monolithic chip.
● Multi-mode operation maximizes efficiency at all loads
● Low thermal impedance junction-to-case
● Low height is ideal for adapters where space is limited
● Simple mounting using a clip to aid low manufacturing
● Output overvoltage protection is user programmable for latching/non-latching shutdown with AC reset
● Allows both primary and secondary sensing
● Line undervoltage detection prevents turn-OFF glitches
● Line overvoltage shutdown extends line surge limit
● Accurate programmable current limit
● Optimized line feed-forward for line ripple rejection
● Frequency jittering reduces EMI filter
● Heat sink is connected to SOURCE for low EMI
● Accurate hysteretic thermal shutdown function automatically recovers without requiring a reset
● Fully integrated soft-start for minimum start-up stress
● Extended creepage between DRAIN and all other pins improves field reliability
● Improved auto-restart delivers <3% of maximum power in short circuit and open loop fault conditions
● 132kHz Frequency reduces transformer and power supply size
