SY21143ADC - High Efficiency, 500kHz, 3A, 23V Input Synchronous Step Down Regulator


  • Low RDS(ON) for Internal Switches (Top/Bottom): 105mΩ/50mΩ
  • 4.5-23V Input Voltage Range
  • 3A Output Current Capability
  • 500 kHz Switching Frequency
  • Instant PWM Architecture to Achieve Fast Transient Responses.
  • Cycle-by-cycle Peak Current Limitation
  • Internal Softstart Limits The Inrush Current
  • Hic-Cup Mode Output Short Circuit Protection
  • ±1.5% 0.6V Reference
  • TSOT23-6 Package

Typical Application


The SY21143 is a high efficiency 500 kHz synchronous step down DC/DC converter capable of delivering 3A current. The SY21143 operates over a wide input voltage range from 4.5V to 23V and integrates main switch and synchronous switch with very low RDS(ON) to minimize the conduction loss.

Low output voltage ripple and small external inductor and capacitor sizes are achieved with 500 kHz switching frequency. It adopts the instant PWM architecture to achieve fast transient responses for high step down applications.


  • Set Top Box
  • Portable TV
  • Access Point Router
  • DSL Modem
  • LCD TV