The CS5141X products are 1.5 A buck regulator ICs. These devices are fixedfrequency operating at 260 kHz and 520 kHz. The regulators use the V2 control architecture to provide unmatched transient response, the best overall regulation and the simplest loop compensation for today's highspeed logic. These products accommodate input voltages from 4.5 V to 40 V. The CS51411 and CS51413 contain synchronization circuitry. The CS51412 and CS51414 have the option of powering the controller from an external 3.3 V to 6.0 V supply in order to improve efficiency, especially in high input voltage, light load conditions. The onchip NPN transistor is capable of providing a minimum of 1.5 A of output current, and is biased by an external "boost" capacitor to ensure saturation, thus minimizing onchip power dissipation. Protection circuitry includes thermal shutdown, cyclebycycle current limiting and frequency foldback. The CS51411 and CS51413 are functionally pincompatible with the LT1375. The CS51412 and CS51414 are functionally pincompatible with the LT1376. Features