The TOP234YN is a design flexible, EcoSmart®, Integrated Off-line Switcher with 45W open frame at 85 to 265VAC. TOPSwitch-FX uses the proven TOPSwitch topology and cost effectively integrates many new functions that reduce system cost and at the same time, 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 MULTIFUNCTION (M) pin, which implements programmable line OV/UV shutdown and line feed forward/DC (max) 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, lower frequency signal.
Feature
- Fully integrated soft-start for minimum stress/overshoot
- Externally settable accurate current limit
- Wider duty cycle for more power, smaller input capacitor
- No turn off glitches line under-voltage (UV) detection
- Line over voltage (OV) shutdown extends line surge limit
- Regulates to zero load without dummy loading
- 132kHz Frequency reduces transformer/power supply size
- Half frequency option for video applications
- Hysteretic thermal shutdown for automatic recovery
- Large thermal hysteresis prevents PC board over heating
- Synchronizable to a lower frequency
- Cycle skipping reduces no-load consumption
- Reduced consumption in remote off mode
- Allows shutdown/wake-up via LAN/input port
