The CS5141X products are 1.5 A buck regulator ICs. These devices are fixed−frequency 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 high−speed 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 on−chip 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 on−chip power dissipation. Protection circuitry includes thermal shutdown, cycle−by−cycle current limiting and frequency foldback. The CS51411 and CS51413 are functionally pin−compatible with the LT1375. The CS51412 and CS51414 are functionally pin−compatible with the LT1376.