LinkSwitch®-XT Family Energy Efficient, Low Power Off-Line Switcher
IC
Description
LinkSwitch-XTincorporates a 700 V power MOSFET, oscillator, simple
ON/OFF control scheme, a high-voltage switched current source,
frequency jittering, cycle-by-cycle current limit and
thermal shutdown circuitry onto a monolithic IC. The startup and
operating power are derived directly from the DRAIN pin,
eliminating the need for a bias winding and associated circuitry.
Product Highlights
Optimized for Lowest System Cost
• Proprietary IC trimming and transformer construction techniques
enable Clampless™ designs with LNK362 for lower system cost,
component count and higher efficiency
• Fully integrated auto-restart for short circuit and open loop
protection
• Self-biased supply – saves transformer auxiliary winding and
associated bias supply components
• Frequency jittering greatly reduces EMI
• Meets HV creepage requirements between DRAIN and all other pins
both on the PCB and at the package
• Lowest component count switcher solution
Features Superior to Linear/RCC
• Accurate hysteretic thermal shutdown protection – automatic
recovery improves field reliability
• Universal input range allows worldwide operation
• Simple ON/OFF control, no loop compensation needed
• Eliminates bias winding – simpler, lower cost transformer
• Very low component count – higher reliability and single side
printed circuit board
• Auto-restart reduces delivered power by 95% during short circuit
and open loop fault conditions
• High bandwidth provides fast turn-on with no overshoot and
excellent transient load response
EcoSmart®
– Extremely Energy-Efficient
• Easily meets all global energy efficiency regulations with no
added components
• No-load consumption <300 mW without bias winding at 265 VAC
input (<50 mW with bias winding)
• ON/OFF control provides constant efficiency to very light loads –
ideal for mandatory CEC regulations
Applications
• Chargers/adapters for cell/cordless phones, PDAs, digital
cameras, MP3/portable audio players, and shavers
• Supplies for appliances, industrial systems, and metering
