MP172 is a primary-side regulator that provides accurate constant voltage (CV) regulation without an opto-coupler. It supports buck, boost, buck-boost, and flyback topologies. It has an integrated 700 V 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. MP172 is a green-mode operation regulator. Both the peak current and the switching frequency decrease as the load decreases. This feature provides excellent efficiency at light load and improves the overall average efficiency. MP172 has various protection features including thermal shutdown (TSD), VCC under-voltage lockout (UVLO), overload protection (OLP), short-circuit protection (SCP), and open-loop protection. MP172 is available in a small TSOT23-5 package and SOIC-8 package.