• Low R_DS(ON) for Internal Switches (Top/Bottom): 29mΩ/19mΩ
• 4.5-18V Input Voltage Range
• 6A Output Current Capability
• 400kHz Switching Frequency Minimize the External Components
• Stable with 22µF C_OUT and 1µH 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 SY21197 high-efficiency synchronous step-down DC/DC regulator operates over a wide input voltage range of 4.5V to 18V, and can deliver an output current up to 6A. It integrates a main switch and a synchronous switch with very low R_DS(ON) to minimize conduction loss. The 400kHz pseudoconstant switching frequency enables using small external inductor and capacitor values

The SY21197 uses constant-on-time and ripple-based control to provide high efficiency at light loads, and to achieve fast transient responses for applications with high step-down ratios. It also provides cycle-by-cycle current limiting and overtemperature protection.

The SY21197 is available in a compact TSOT23-6 package.