Regulator powers low voltage DSPs and MCUs

High-efficiency synchronous buck regulator runs from Li-ion/polymer battery inputs as well as 3.3 or 5V inputs for point-of-load applications.

The Linear Technology LTC3568 is a high-efficiency 4MHz synchronous buck regulator that delivers up to 1.8A of continuous output current from a 3 x 3mm DFN package.

Using a constant frequency and current mode architecture, the LTC3568 operates from an input voltage range of 2.5 to 5.5V, making it ideal for Li-ion/polymer battery inputs as well as 3.3 or 5V inputs for point-of-load applications.

It can generate output voltages as low as 0.8V, enabling it to power the latest generation of low voltage DSPs and microcontrollers.

Its switching frequency is programmable from 850kHz to 4MHz, enabling use with tiny, low cost ceramic capacitors and inductors less than a 1mm in height, providing a highly compact solution footprint.

The LTC3568 uses internal switches with an on-resistance of only 0.11ohm (N-channel and P-channel) to deliver efficiencies as high as 96%.

It also uses low-dropout 100% duty cycle operation to allow output voltages equal to the input level, further extending battery runtime.

The LTC3568 uses Burst Mode operation to offer only 60uA of no-load quiescent current.

If the application is noise sensitive, the Burst Mode operation can be replaced with a lower noise pulse-skipping mode.

In both modes, the device maintains a shutdown current less than 1uA.

To reduce noise even further, the LTC3568's switching frequency is also synchronisable to an external clock between 400kHz and 4MHz.

Other features include +/-2% output voltage accuracy, short-circuit protection, internal soft-start and overtemperature protection.

The LTC3568EDD comes in a 3 x 3mm DFN-6 package and is available from stock.

Pricing starts at US $2.95 each for both parts in 1000-piece quantities.

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