Linear Technology has a 4MHz synchronous buck regulator that uses a constant frequency controlled on-time, current mode architecture.

The LTC3605 delivers up to 5A of continuous output current at output voltages as low as 0.6V with minimum thermal de-rating from a 4x4mm QFN package.

It operates from an input voltage of 4V to 15V, making it suitable for dual-cell Li-Ion applications, as well as fixed rail systems with voltages up to 12V. The switching frequency is user programmable from 800kHz to 4MHz.

The regulator uses internal N-channel switches with RDS(ON)s of only 35mΩ and 70mΩ to deliver efficiencies as high as 96%. Its low minimum on-time allows low duty cycle operation at high switching frequencies.

The device’s PolyPhase operation (up to 12 phases) allows multiple regulators to be cascaded, running out of phase to minimize input and output capacitance. Current mode operation offers fast transient response while simplifying compensation.

More information: www.linear.com