VIPER53 DIP8 ORIGINAL

Features
■ Switching frequency up to 300kHz
■ Current limitation
■ Current mode control with adjustable limitation
■ Soft start and shut-down control
■ Automatic burst mode in standby condition
(“Blue Angel“ compliant )
■ Undervoltage lockout with Hysteresis
■ HIgh voltage star-tup current source
■ Overtemperature protection
■ Overload and short-circuit control

The switching frequency can be set to any value through the choice of R3 and C5. This
allows to optimize the efficiency of the converter by adopting the best compromise between
switching losses, EMI (Lower with low switching frequencies) and transformer size (Smaller
with high switching frequencies). For an output power of a few watts, typical switching
frequencies between 20kHz and 40kHz because of the small size of the transformer. For
higher power, 70kHz to 130kHz are generally chosen.
The R5 compensation resistor value sets the dynamic behavior of the converter. It can be
adjusted to provide the best compromise between stability and recovery time with fast load
changes