Offline Primary Side 3W Regulator, 30mW No-Load Power



MP156 is a primary-side regulator that provides accurate constant voltage (CV) regulation without opto-coupler, support buck, buck-boost, or flyback topologies. It has an integrated 500V MOSFET to simplify the structure and reduce costs. These features make it a competitive candidate for off-line low power applications, such as home appliances and standby power. MP156 is a green-mode operation regulator. Both its the peak current and the switching frequency decrease as the load decreases to provide excellent efficiency at light load, thus improving the overall average efficiency. MP156 features various protections, including thermal shutdown (TSD), VCC under-voltage lockout (UVLO), overload protection (OLP), short-circuit protection (SCP), and open loop protection. MP156 is available in the TSOT23-5  and SOIC8 packages.


  • Primary-side constant voltage (CV) control, supporting buck, buck-boost and flyback topologies 
  • Integrated 500V/20Ω MOSFET 
  • <30mW no-load power consumption 
  • Up to 4W output power 
  • Maximum DCM output current less than 130mA 
  • Maximum CCM output current less than 220mA 
  • Low VCC Operating Current 
  • Frequency foldback 
  • Limited maximum frequency 
  • Peak-current compression 
  • Internal high-voltage current source 
  • Internal 350ns leading-edge blanking 
  • Thermal shutdown (auto restart) 
  • VCC under voltage lockout with hysteresis 
  • Timer based over-load protection 
  • Short-circuit protection 
  • Open-loop protection


  • Vac (max) (V)265
  • Vfb (V)2.5
  • ICC Latch (typ) (µA)16
  • Vbr (V)500
  • Rds(on) (Ω)20
  • fsw (max) (kHz)56
  • Isw Limit (mA)290
  • Iout (DCM) (max) (mA)130
  • Iout (CCM) (max) (mA)220
  • Pout (max) (W)3
  • Vac (min) (V)20
  • VCC Off (V)3.4
  • Power Range DefinedNo
  • Control MethodOn-Off
  • PackageSOIC-8, TSOT23-5
  • GradeCatalog
  • TypeBuck Regulator
  • VCC Hysteresis (V)0.25
  • Min Off Time (typ) (µs)18
  • VCC Restart (V)2.4
  • No-Load Pout (max) (mW)30
  • Iregulator (mA)3.5
  • Ileak (µA)10