• Low R_DS(ON) for Internal Switches (Top/Bottom): 80mΩ/40mΩ
• 4.2-18V Input Voltage Range
• 3A Output Current Capability
• 500kHz Switching Frequency Minimize the External Components
• Stable with 10µF C_OUT and 2.2µH Inductor
• Instant PWM Architecture to Achieve Fast Transient Responses
• Internal Soft-start Limits the Inrush Current
• Cycle-by-cycle Peak/Valley Current Limitation
• Hic-cup Mode Output Short Circuit Protection
• Thermal Shutdown with Auto Recovery
• Output Auto Discharge Function
• Compact Package: TSOT23-6

The SY21113I is a high efficiency, 500kHz synchronous step-down DC/DC regulator capable of delivering up to 3A load current. It can operate over a wide input voltage range from 4.2V to 18V and integrate main switch and synchronous switch with very low R_DS(ON) to minimize the conduction loss.

The SY21113I adopts the instant PWM architecture to achieve fast transient responses for high step down applications and high efficiency at light loads. In addition, it operates at pseudo-constant frequency of 500kHz to minimize the size of the inductor and the capacitor.