The MP174 is a primary-side regulator that provides accurate constant voltage (CV) regulation without opto-coupler. It supports Buck, BuckBoost, Boost and Flyback topologies. It has an integrated 700V MOSFET to simplify the structure and reduce costs. These features make it an ideal regulator for off-line low power applications, such as home appliances and standby power. MP174 is a green-mode-operation regulator. Both the peak current and switching frequency decrease as the load decreases. This feature provides excellent efficiency at light load, and improves the overall average efficiency. MP174 features various protections, including thermal shutdown (OTP), VCC under-voltage lockout (UVLO), overload protection (OLP), short-circuit protection (SCP), and open loop protection. MP174 is available in small TSOT23-5 package and SOIC8 package.Primary-side CV control, supporting Buck, Buck-Boost, Boost and Flyback topologies Integrated 700V/13.5? MOSFET and current source <30mW no-load power consumption Up to 5W output power Maximum DCM output current less than 250mA Maximum CCM output current less than 400mA Low VCC Operating Current Frequency foldback Limited maximum frequency Peak-current compression Internally biased VCC OTP, UVLO, OLP, SCP, open loop protection