SEPIC/boost DC/DC converter suits always-on applications

16th July 2015

Barney Scott

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Datasheet

Linear Technology Corporation has announced the LT8494, a current mode, fixed frequency SEPIC/boost DC/DC converter with an internal 2A, 70V switch. Ultralow quiescent current of only 7µA makes the device suitable for always-on automotive or other industrial battery powered systems. The LT8494 starts up from an input voltage range of 2.5V to 32V and once running it operates from inputs from 1 to 60V.

The converter is suitable for applications with input sources ranging from a single-cell Li-Ion to automotive inputs. The LT8494 can be configured as a boost, SEPIC or flyback converter. Its switching frequency can be programmed via a single resistor between 250kHz and 1.5MHz, enabling designers to minimise external component sizes. The combination of a thermally enhanced TSSOP-20E or 4mm² QFN package and tiny externals ensures a very compact footprint while minimising solution cost.

The LT8494’s internal, high efficiency 2A/70V switch delivers efficiencies of up to 83% while operating in a SEPIC configuration. A unique design using dual supply pins (V_IN and BIAS) enables the device to operate from the most efficient supply, optimising efficiency over a wide range of conditions. The LT8494 can operate with input supply voltages up to 60V for SEPIC topology and up to 32V, with ride through protection in boost and flyback topologies. Other features include a FMEA tolerant package (TSSOP-20E), power good indicator, programmable soft-start and thermal shutdown protection.

The LT8494 is available in a thermally enhanced TSSOP-20 package. Pricing starts at $2.85 each for 1,000 piece quantities. Industrial temperature (-40 to +125°C) and high temperature (-40 to +150°C) grades are also available. All versions are available from stock.