• Low R_DS(ON) for Internal Switches (Top/Bottom): 130mΩ/105mΩ
• 4.5~18V Input Voltage Range
• 2A Output Current Capability
• 1.4MHz Switching Frequency Minimize the External Components
• Stable with 10µF C_OUT and 1.0µH Inductor
• Instant PWM Architecture to Achieve Fast Transient Responses
• Internal Soft-start Limits the Inrush Current
• Forced PWM Operation
• Cycle-by-cycle Peak/Valley Current Limitation
• Hic-cup Mode Output Short Circuit Protection
• Thermal Shutdown with Auto Recovery
• Compact Package SOT23-6

The SY21081B1 is a high efficiency, synchronous step-down DC/DC converter capable of delivering 2A load current. The SY21081B1 operates over a wide input voltage range from 4.5V to 18V and integrates main switch and synchronous switch with very low R_DS(ON) to minimize the conduction loss.

The SY21081B1 adopts the instant PWM architecture to achieve fast transient responses for high step down applications. In addition, it operates at pseudo-constant frequency of 1.4MHz to minimize the size of inductor and capacitor.