Linear Technology LTC3614 synchronous buck regulator

The LTC3614 is a high-efficiency synchronous buck regulator from Linear Technology that incorporates a constant frequency, current mode architecture capable of switching frequencies up to 4 MHz.

Low-resistance internal switches allow delivery of up to 4A of continuous output current from a 3 x 5 mm QFN package and its low drop-out operation allows the output voltage to range from 0.6 V to just millivolts below V_in.

The regulator operates over an input voltage range of 2.25 to 5.5, making it suitable for single-cell Li-Ion applications as well as 3.3 or 5 V intermediate bus systems.

Its switching frequency is user programmable from 300 kHz to 4 MHz, enabling the use of tiny, capacitors and inductors.

The buck regulator uses internal switches with RDS(ON) of only 25 and 35 mΩ to deliver efficiencies of up to 95%. Burst mode operation reduces no-load quiescent current to 75 µA, maximising light-load efficiency and run time in battery-powered applications. The regulator has an adjustable burst mode clamp.

It can be configured to run in either pulse-skipping or forced continuous mode, reducing noise and potential RF interference. Programmable switching slew rates can further reduce potential noise concerns.

It has tracking capability as well as a DDR memory mode in which the device can source/sink ±3 A and has optional active voltage positioning, a power high voltage monitor, external synchronisation capability and thermal protection.

The EUDD is available in a 3 x 5 mm QFN-24. An industrial version, the LTC3614IUDD is guaranteed to meet specifications over the -40 to 125°C operating junction temperature range.

Its features include: Low output ripple (\<20 mVPK-PK) burst mode operation: IQ = 75µA; ±1% output voltage accuracy; programmable soft-start; inputs for start-up tracking or external reference.