Enhanced, Energy Efficient, Low Power Off-line Switcher

Description
TinySwitch-IIintegrates a 700 V power MOSFET, oscillator, high  voltage  switched  current source,  current  limit  and thermal  shutdown  circuitry  onto  a  monolithic  device.  The start-up  and  operating  power  are  derived  directly  from the  voltage  on  the  DRAIN  pin,  eliminating  the  need  for a  bias  winding  and  associated  circuitry.  In  addition,  the TinySwitch-II devices  incorporate  auto-restart,  line  under voltage sense, and frequency jittering. An innovative design
minimizes audio frequency components in the simple ON/OFF control  scheme  to  practically  eliminate  audible  noise  with standard taped/varnished transformer construction. The fully
integrated auto-restart circuit safely limits output power during fault  conditions  such  as  output  short  circuit  or  open  loop, reducing component count and secondary feedback circuitry cost.

Product Highlights
TinySwitch-IIFeatures Reduce System Cost
•  Fully integrated auto-restart for short circuit and open loop fault protection – saves external component costs
•  Built-in circuitry practically eliminates audible noise with ordinary dip-varnished transformer
•  Programmable line under-voltage detect feature prevents power on/off glitches – saves external components
•  Frequency jittering dramatically reduces EMI (~10 dB)
   – minimizes EMI filter component costs
•  132 kHz operation reduces transformer size – allows use of EF12.6 or EE13 cores for low cost and small size
•  Very tight tolerances and negligible temperature variation on key parameters eases design and lowers cost
•  Lowest component count switcher solution
•  Expanded scalable device family for low system cost