1A 2MHz 55V Step-Down Converter Light-Load Efficiency



The MPQ4558 is a high-frequency, step-down switching regulator with an integrated internal high-side high-voltage power MOSFET. It provides up to a 1A output with current-mode control for fast loop response and easy compensation. The wide 4.5V-to-55V input range accommodates a variety of step-down applications, including automotive input. A 12µA shutdown-mode supply current makes it suitable for battery-powered applications. A scaled-down switching frequency in light-load conditions provides high power-conversion efficiency over a wide load range while reducing switching and gate driver losses. The frequency fold-back prevents inductor current runaway during startup and thermal shutdown provides reliable, fault-tolerant operation. By switching at 2MHz, the MPQ4558 can prevent EMI (electromagnetic interference) noise problems, such as those found in AM radio and ADSL applications. The MPQ4558 is available in an SOIC8E and a 10-pin 3mm x 3mm QFN package.


  • Guaranteed Industrial/Automotive Temperature Range Limits
  • Wide 4.5V-to-55V Operating Input Range
  • 250mO Internal Power MOSFET
  • Up to 2MHz Programmable Switching Frequency
  • 140µA Quiescent Current
  • Stable with Ceramic Capacitors
  • Internal Soft-Start
  • Up to 95% Efficiency
  • Output Adjustable from 0.8V to 52V
  • Available in SOIC8E and 3mm x 3mm QFN10 Packages
  • AEC-Q100 Qualified


  • fsw (max) (kHz)2000
  • Vin (min) (V)3.8
  • Vin (max) (V)55
  • Iout (max) (A)1
  • Isw Limit (typ) (A)1.9
  • Vfb (V)0.8
  • Iq (typ) (mA)0.14
  • Regulated Outputs1
  • Vout (max) (V)52
  • Vout (min) (V)0.8
  • PGNo
  • GradeAutomotive
  • PackageQFN-10 (3x3)
  • Control ModeCurrent Mode
  • Common FeaturesLight-Load Efficiency
  • Special FeaturesProgrammable Frequency