Description
PM6680 is a dual step-down controller specifically designed to provide extremely high efficiency conversion, with lossless current sensing technique. The constant on-time architecture assures fast load transient response and the embedded voltage feed-forward provides nearly constant switching frequency operation. An embedded integrator control loop compensates the DC voltage error due to the output ripple. Pulse skipping technique increases efficiency at very light load. Moreover a minimum switching frequency of 33kHz is selectable to avoid audio noise issues. The PM6680 provides a selectable switching frequency, allowing three different values of switching frequencies for the two switching sections. The output voltages OUT1 and OUT2 can be adjusted from 0.9 V to 5.5 V and from 0.9 V to 3.3 V respectively.

Features
■ 6 V to 28 V input voltage range
■ Adjustable output voltages
■ 5 V always voltage available deliver 100 mA peak current
■ 1.237 V ± 1% reference voltage available
■ Lossless current sensing using low side MOSFETs RDS(on)
■ Negative current limit
■ Soft-start internally fixed at 2ms
■ Soft output discharge
■ Latched OVP and UVP
■ Selectable pulse skipping at light loads
■ Selectable minimum frequency (33 kHz) in pulse skip mode
■ 4 mW maximum quiescent power
■ Independent power good signals
■ Output voltage ripple compensation

Applications
■ Notebook computers
■ Tablet PC or slates
■ Mobile system power supply
■ 3-4 cells Li+ battery powered devices