The ISL85003 and ISL85003A are synchronous buck regulators with integrated high-side and low-side FETs. The FETs are designed to have a very low RDS(ON) of 65 and 45 mΩ. Lower RDS(ON) simply means lower conduction loss which leads to higher efficiency. This device provides a very low BOM and a very compact solution because it has integrated high-side and low-side FETs, integrated bootstrap diode, internal compensation, and an internal soft-start, all in a very compact 4 X 3 DFN package. In this device, the switching frequency is internally set to 500kHz. Operating at high switching frequency has two main advantages: it provides a better transient performance and it gives the option to choose smaller sized passive components which leads to an even more compact solution. The main difference between the ISL85003 and ISL85003A is the functionality of pin 1. For the ISL85003, pin 1 is used for external synchronization up to 2MHz. On the ISL85003A, pin 1 is used to adjust soft-start time. Finally, this device is fully protected against overcurrent, over-temperature, overvoltage, and so on.