MP157 is a primary-side regulator providing accurate constant voltage (CV) regulation without the Opto-coupler. It supports Buck, Buck-Boost, Boost and Flyback topologies. A 500V MOSFET is integrated in the regulator, so very simple structure and low cost can be achieved. These features make MP157 an ideal solution for off-line low power applications.  Typical applications include home appliance, standby power and industrial control. MP157 is a green mode operation regulator. When the load decreases, the peak current and the switching frequency decrease with the load. As a result, it still offers excellent efficiency performance at light load, thus better average efficiency is achieved. MP157 features various protections like Thermal Shutdown (TSD), VCC under Voltage Lockout (UVLO), Over Load Protection (OLP), Short Circuit Protection (SCP), Open Loop Protection. MP157 is available in the TSOT23-5 and SOIC8 packages.