The ISL8105B is a simple single-phase PWM controller for a synchronous buck converter. It operates from +5V or +12V bias supply voltage. With integrated linear regulator, boot diode, and N-Channel MOSFET gate drivers, the ISL8105B reduces external component count and board space requirements. These make the IC suitable for a wide range of applications. Utilizing voltage-mode control, the output voltage can be precisely regulated to as low as 0.6V. The 0.6V internal reference features a maximum tolerance of 1.0% over the commercial temperature range, and 1.5% over the industrial temperature range. The controller operates with a fixed switching frequency of 300kHz. The ISL8105B features the capability of safe start-up with pre-biased load. It also provides overcurrent protection by monitoring the ON-resistance of the bottom-side MOSFET to inhibit PWM operation appropriately. During start-up interval, the resistor connected to BGATE/BSOC pin is employed to program overcurrent protection condition. This approach simplifies the implementation and does not deteriorate converter efficiency.