SY21085ADC -


  • Low RDS(ON) for Internal Switches (Top/Bottom): 130mΩ/60mΩ
  • 4.5-23V Input Voltage Range
  • 2A Output Current Capability
  • 500 kHz Switching Frequency
  • Instant PWM Architecture to Achieve Fast Transient Responses
  • Cycle-by-cycle Peak Current Limitation
  • Internal Soft-start Limits the Inrush Current
  • Hic-cup Mode Output Short Circuit Protection
  • Output Discharge Function
  • ±1.5% 0.6V Reference
  • Power Good Indicator (SY21085AIC only)
  • TSOT23-8/ TSOT23-6 Package

Typical Application


The SY21085 is a high efficiency 500 kHz synchronous step-down DC-DC converter capable of delivering 2A current. The SY21085 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