Hysteretic Non Synchronous PFET Buck Controller, 4.5V to 35V, Single Channel Output, Buck, 1MHz, VSSOP-8 - 

The LM3485MM/NOPB is a hysteretic non-synchronous PFET Buck Controller used to quickly and easily develop a small switching buck regulator for a wide range of applications. The hysteretic control architecture provides for simple design without any control loop stability concerns using a wide variety of external components. The PFET architecture also allows for low component count as well as ultra-low dropout, 100% duty cycle operation. Another benefit is high efficiency operation at light loads without an increase in output ripple. Current limit protection is provided by measuring the voltage across the PFET's RDS(ON), thus eliminating the need for a sense resistor. The cycle-by-cycle current limit can be adjusted with a single resistor, ensuring safe operation over a range of output currents.