The TOP233YN is a 20W design flexible integrated Off-Line Switcher uses the proven TOPSwitch topology and it integrates many new functions to improve design flexibility, performance and energy efficiency. Like TOPSwitch the high voltage power MOSFET, PWM control, fault protection and other control circuitry are all integrated onto a single CMOS chip but with two added terminals. The first one is a multi-function (M) pin which implements programmable line OV/UV shutdown and line feed forward/DCMAX reduction with line voltage. The same pin can be used instead to externally set an accurate current limit. In either case this pin can also be used for remote ON/OFF or to synchronize the oscillator to an external and lower frequency signal. The second added terminal is the frequency (F) pin. This pin provides the half frequency option when connected to control (C) instead of source (S).
● Fully integrated soft-start for minimum stress/over-shoot
● Externally settable accurate current limit
● Wider duty cycle for more power, smaller input capacitor
● Line under-voltage detection - No turn OFF glitches
● Line over-voltage shutdown extends line surge limit
● Regulates to zero load without dummy loading
● Hysteretic thermal shutdown for automatic recovery
● Large thermal hysteresis prevents PC board over-heating
● Active-ON and active-OFF remote ON/OFF capability
● Synchronizable to a lower frequency
