RT7274

® RT7274/79/80/81 2A, 18V, 700kHz ACOTTM Synchronous Step-Down Converter General Description The RT7274/79/80/81 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 2A 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 capacitor for ensuring performance stabilization. In addition, RT7274/79/80/81 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 include thermal shutdown for RT7274/79/80/81; output under voltage protection and output over voltage protection for RT7279/80 only. Features z ACOTTM Mode Enables Fast Transient Response z 4.5V to 18V Input Voltage Range z 2A Output Current z High Efficient Internal N-MOSFET Optimized for Lower Duty Cycle Applications z 105mΩ Internal Low-Side N-MOSFET z Advanced Constant On-Time Control z Allows Ceramic Output Capacitor z 700kHz Switching Frequency z Adjustable Output Voltage from 0.765V to 8V z Adjus...