RICHTEK RT7277GSP

The RT7277 is a synchronous step-down DC/DC converter with Advanced Constant On-Time (ACOTTM) mode control. It achieves high power density to deliver up to 3A output current from a 4.5V to 18V input supply. The proprietary ACOTTM mode offers an optimal transient response over a wide range of loads and all kinds of ceramic capacitors, which allows the device to adopt very low ESR output capacitors for ensuring performance stabilization. In addition, RT7277 keeps an excellent constant switching frequency under line and load variation and the integrated synchronous power switches with the ACOTTM mode operation provides high efficiency in whole output current load range. Cycle-by-cycle current limit provides an accurate protection by a valley detection of low side MOSFET and external soft-start setting eliminates input current surge during startup. Protection functions also include output under voltage protection, output over voltage protection, and thermal shutdown.

• ACOTTM Mode Enables Fast Transient Response
• 4.5V to 18V Input Voltage Range
• 3A Output Current
• 60mΩ Internal Low Site N-MOSFET
• Advanced Constant On-Time Control
• Support All Ceramic Capacitors
• Up to 95% Efficiency
• 700kHz Switching Frequency
• Adjustable Output Voltage from 0.765V to 8V
• Adjustable Soft-Start
• Cycle-by-Cycle Current Limit
• Input Under Voltage Lockout
• Thermal Shutdown
• RoHS Compliant and Halogen Free

• Industrial and Commercial Low Power Systems
• Computer Peripherals
• LCD Monitors and TVs
• Green Electronics/Appliances
• Point of Load Regulation for High-Performance DSPs, FPGAs, and ASICs