SY21228LQQC - High Efficiency Fast Response 8A Continuous, 16A Peak, 28V Input Synchronous Step Down Regulator


  • Fast Transient Response
  • Wide Input Voltage Range: 4.5-28V
  • Low RDS(ON) for Internal Switches(Top FET/Bottom FET):20mΩ/10mΩ
  • 8A Continuous/16A Peak Output Current Capability
  • Accurate Feedback Reference Voltage: 0.6V ±1%
  • Pseudo-constant 500kHz Operating Frequency
  • Internal 600µs Soft-start Limits Inrush Current
  • PSM/FCCM Selectable Light Load Operation Mode
  • Power Good Indicator
  • Cycle-by-Cycle Current Limit
  • Latch Off  Mode Output Under Voltage and Over Voltage Protection
  • Over Temperature Protection with Auto Recovery
  • Compact Package: QFN3×3-12

Typical Application


The SY21228L is a high-efficiency synchronous step-down DC/DC regulator featuring internal power and synchronous rectifier switches capable of delivering 8A of continuous output current and up to 16A peak output current over a wide input voltage ranging from 4.5V to 28V.

Silergy’s proprietary Instant-PWM™ fast-response, constant-on-time (COT) PWM control method supports high input/output voltage ratios (low duty cycles), and fast transient response while maintaining a near constant operating frequency over line, load and output voltage ranges. This control method provides stable operation without complex compensation and even with low ESR ceramic capacitors.

Internal 20mΩ power and 10mΩ synchronous rectifier switches provide excellent efficiency over a range of applications, especially for low output voltages and low duty cycles. Cycle-by-cycle current limit, input under voltage lock-out, internal soft-start, output under and over voltage protection, and over temperature protection provide safe operation in all operating conditions.

The SY21228L is available in a compact QFN3×3-12 package.


  • LCD-TV/Net-TV/3DTV
  • Set Top Box
  • Notebook
  • High Power AP