电路保护(SCP),逐脉冲电流限制,过载保护(OLP)和过热保护(OTP)。
220v转变固定5v输出芯片:

The TT119 is a high efficiency low cost
off-line constant voltage regulator for Buck
and Buck- Boost topology with 500V
MOSFET integrated.
TT119 can output 5V default voltage with
few external components, whichdecreases the system cost. In light load
condition, TT119 operates in green mode, in which the inductor peak current
and the switching frequency is lower than that of full load to improve the system
efficiency and the reference voltage is
decreased to ensure good load regulation.
TT119 has multi-protection functions which largely enhance the safety
and reliability of the system, including VDD under-voltage Lockout (UVLO), short
circuit protection (SCP), pulse-by- pulse current limit, over load protection (OLP)
and over-temperature protection (OTP).