21V, 3A, 500kHz Synchronous Step-down Converter

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Product Description

The MPQ28261 is a synchronous, rectified, step-down, switch-mode converter with built-in 120mΩ high-side MOSFET and 20mΩ low-side MOSFET. It offers a very compact solution to achieve a continuous 3A output current over a wide input supply range, with excellent load and line regulation. Its synchronous mode operation increases its efficiency over its output current load range, and uses a fixed 500kHz switching frequency.  Current mode operation provides a fast transient response and improves loop stabilization. Full protection features include over-current protection and thermal shut down.  The MPQ28261 has an external SS pin to program the soft-start time and power-good signal output.  The MPQ28261 requires a minimal number of readily-available standard external components and is available in a space saving 3mmx4mm 14-pin QFN package.


Product Features

  • Wide 4.5V-to-21V Operating Input Range
  • 3A Maximum Continuous Output Current
  • Integrated 120mΩ High-Side and 20mΩ Low-Side Power MOSFETs
  • 1% Reference Voltage Accuracy
  • Up to 85% Efficiency (for Drops of 12V to 1.2V)
  • Fixed 500kHz Switching Frequency
  • External Soft-Start
  • PG Output
  • OCP and Thermal Shutdown
  • Output Adjustable from 0.603V to 18V
  • Available in a 3mm x 4mm 14-pin QFN Package.


  • fsw (max) (kHz)500
  • Vin (min) (V)4.5
  • Vin (max) (V)21
  • Iout (max) (A)3
  • Isw Limit (typ) (A)5.2
  • Max Duty Cycle (%)0.92
  • Vfb (V)0.603
  • Iq (typ) (mA)0.7
  • Regulated Outputs1
  • Vout (max) (V)18
  • Vout (min) (V)0.603
  • GradeIndustrial
  • PackageQFN-14 (3x4)
  • Control ModeCurrent Mode
  • Common FeaturesExternal Soft Start, Power Good, Synchronous Rectification

21V, 3A 500kHz Synchronous Step-down Converter EV Board

The EVQ28261-L-00A is for demonstrating MPS’s MPQ28261, a high frequency synchronous rectified step-down switch mode converter with built in internal power MOSFETs. MPQ28261 offers a very compact solution to achieve 3A continuous output current over a wide input supply range with excellent load and line regulation. The MPQ28261 operates at high efficiency over a wide output current load range.

Current mode operation provides fast transient response and eases loop stabilization. The full protection features include OCP and thermal shutdown.

The MPQ28261 requires a minimum number of readily available standard external components and comes in a space saving 3x4mm 14-pin QFN package.

$25.00 + tax

Reference Materials

Quality Policy, Certificates & Reliability Reports
All MPS parts are lead-free, halogen-free and adhere to the RoHS directive. See Environmental section for details.