High Efficiency 3A Peak, 36V, Synchronous Step-Down Converter With Power Good



The MP9943A is a high-frequency, synchronous, rectified, step-down, switch-mode converter with built-in power MOSFETs. It offers a very compact solution to achieve a 3A peak output current with excellent load and line regulation over a wide input supply range. The MP9943A has synchronous mode operation for higher efficiency over the output current load range. Current-mode operation provides fast transient response and eases loop stabilization. Full protection features include over-current protection and thermal shutdown. The MP9943A requires a minimal number of readily-available standard external components, and is available in a space-saving QFN-8 (3mmx3mm) package.



  • Wide 4V to 30V Continuous Operating Input Range
  • 36V Input Transient Tolerance
  • 85mO/55mO Low RDS(ON) Internal Power MOSFETs
  • High-Efficiency Synchronous Mode Operation
  • 410kHz Switching Frequency
  • Synchronizes from 200kHz to 2.2MHz External Clock
  • High Duty Cycle for Automotive Cold-crank
  • Force CCM Mode
  • Power Good Indicator
  • Over Current Protection and Hiccup
  • Thermal Shutdown
  • Output Adjustable from 0.8V
  • Available in an QFN-8 (3mmx3mm) package


  • fsw (max) (kHz)410
  • 最小输入电压4
  • Vin (max) (V)30
  • Iout (max) (A)3
  • Isw Limit (typ) (A)5.5
  • Max Duty Cycle (%)0.95
  • Vfb (typ) (V)0.792
  • Iq (typ) (mA)0.5
  • 额定输出1
  • Vout (max) (V)28.5
  • Vout (min) (V)0.8
  • GradeCatalog
  • PackageQFN-8 (3x3)
  • Control ModeCurrent Mode
  • Common FeaturesForced CCM, Power Good, Synchronous Rectification
  • Special Features外部频率同步