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Step-up converter offers buck-boost functionality at the cost of a boost converter

austriamicrosystems has introduced a 200 mA boost converter that provides a continuous transition between boost and regulated buck mode which makes the device ideal for single for dual cell applications.

The topology of the AS1337 provides an innovative step down function enabling buck-boost functionality.

The AS1337 DC-DC buck-boost converter offers an adjustable output voltage range from 2.5 to 5.0 V from an input voltage range of 0.65 V to 4.5 V. From a two cell battery with a voltage range between 1.8V and 3.6 V the AS1337 offers 200 mA of output current at 3 V. From a single cell 100 mA can still be generated. Combined with two small capacitors and one chip-scale inductor the AS1337 provides a small and low profile footprint solution, typically required in battery powered applications. The low voltage DC-DC IC offers power-ok signaling.

austriamicrosystems' AS1337 implements innovative boost architecture with efficiencies up to 97 percent. The converter is capable of entering into buck mode when the input voltage is higher than the output voltage and therefore adopts a buck-boost behavior at the cost of a single boost converter.

In shutdown mode the AS1337B version offers a battery disconnect function, where the input is disconnected from the output. The AS1337A connects the input to the output enabling the supply of e.g. real time clocks or memories during shutdown for example. austriamicrosystems' AS1337 draws only 10 nA shutdown current, which further extends battery life time.

“Especially in dual cell applications the input voltage can be up to 3.6 V when using fresh batteries. Even though this voltage is only available for a very short time, it can damage a 3 V system. AS1337 enters a regulated buck mode in order to avoid this problem. A conventional boost converter does not regulate the output voltage in this case. The customer gets buck-boost behavior at the cost of a standard boost converter” commented Bruce Ulrich, Marketing Director Consumer and Communications at austriamicrosystems.

Availability

The AS1337 is available in a small TDFN (3×3)-8 package and is suitable for operating temperatures ranging from -40 to +85 degrees C.

Datasheet:

AS1337

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