4A, Fast Transient, 4.2V to 20V Input Synchronous Step-Down Converter



The MP28257 is a fully-integrated, synchronous, step-down, switch-mode converter with a programmable frequency. It offers a very compact solution that can provide up to 4A of continuous output current over a wide input supply range with excellent load and line regulation, and can operate at high efficiency over a wide output current load range. Constant-on-time control mode provides fast transient response and eases loop stabilization.  Protections include short-circuit protection, over-current protection, over-voltage protection, under-voltage protection, and thermal shut down.   The MP28257 requires a minimal number of readily-available standard external components.  The device is available in a space saving 2mmx3mm QFN12 package that complies with ROHS.



  • Wide 4.2V-to-20V Operating Input Range
  • 4A Continuous Output Current
  • Internal 120mΩ High-Side, 50mΩ Low-Side Power MOSFETs
  • Stable with Ceramic Output Capacitors
  • Proprietary Switching Loss-Reduction Technology
  • Power-Good Indicator
  • Soft Startup/Shutdown
  • Programmable Switching Frequency
  • SCP, OCP, OVP, UVP Protection and Thermal Shutdown
  • Output Adjustable from 0.815V to 13V
  • Available in a 2mmx3mm QFN12 Package


  • fsw (max) (kHz)0
  • Vin (min) (V)4.2
  • Vin (max) (V)20
  • Iout (max) (A)4
  • Isw Limit (typ) (A)7
  • Vfb (V)0.815
  • Iq (typ) (mA)0.36
  • Regulated Outputs1
  • Vout (max) (V)13
  • Vout (min) (V)0.815
  • GradeCatalog
  • PackageQFN-12 (2x3)
  • Control ModeCOT
  • Common FeaturesLight-Load Efficiency, Power Good, Synchronous Rectification
  • Special FeaturesProgrammable Frequency