RT7275

® RT7275/76 3A, 18V, 700kHz ACOTTM Synchronous Step-Down Converter General Description The RT7275/76 are high-performance 700kHz 3A stepdown regulators with internal power switches and synchronous rectifiers. They feature quick transient response using their Advanced Constant On-Time (ACOT TM) control architecture that provides stable operation with small ceramic output capacitors and without complicated external compensation, among other benefits. The input voltage range is from 4.5V to 18V and the output is adjustable from 0.765V to 8V. The proprietary ACOTTM control improves upon other fastresponse constant on-time architectures, achieving nearly constant switching frequency over line, load, and output voltage ranges. Since there is no internal clock, response to transients is nearly instantaneous and inductor current can ramp quickly to maintain output regulation without large bulk output capacitance. The RT7275/76 are stable with and optimized for ceramic output capacitors. With internal 90mΩ switches and 60mΩ synchronous rectifiers, the RT7275/76 display excellent efficiency and good behavior across a range of applications, especially for low output voltages and low duty cycles. Cycle-bycycle current limit, input under-voltage lock-out, externally-adjustable soft-start, output under- and overvoltage protection, and thermal shutdown provide safe and smooth operation in all operating conditions. The RT7275 and RT7276 are each available in WDFN-10L 3x3 and PTSSOP-14 packa...