Dual-channel regulator powers low voltage DSPs

Dual-channel high-efficiency 2.25MHz, synchronous buck regulator delivers up to 300mA of continuous output current per channel from a 3 x 2mm DFN package.

Linear Technology has announced the LTC3547, a dual-channel high-efficiency 2.25MHz, synchronous buck regulator that delivers up to 300mA of continuous output current per channel from a 3 x 2mm DFN package.

Using a constant frequency current mode architecture, the LTC3547 operates from an input voltage range of 2.5 to 5.5V, making it ideal for single cell Li-ion/polymer, or multicell alkaline/NiCad/NiMH applications.

It can generate output voltages as low as 0.6V, enabling it to power the latest generation of low voltage DSPs and microcontrollers.

Its 2.25MHz switching frequency enables the use of tiny, low cost ceramic capacitors and inductors less than 1mm in height, providing a very compact solution footprint for handheld applications.

The LTC3547 uses internal switches with an on-resistance of only 0.75ohm (N-channel) and 0.80ohm (P-channel) to deliver efficiencies as high as 96%.

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

The LTC3547 incorporates low ripple Burst Mode operation, offering only 40uA no load quiescent current (both channels) with only 20mV peak-peak of output ripple.

Shutdown current is less than 1uA, further extending battery life.

Each channel has independent internal soft-start, enabling design flexibility.

Other features include short-circuit and overtemperature protection.

The LTC3547EDDB is available from stock in an 8-lead 3 x 2mm DFN package.

Pricing starts at US $1.95 each in 1000-piece quantities.

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