2A, 70V SEPIC/Boost DC/DC converter with 7µA Iq

July 17, 2015 // By Graham Prophet
LT8494 is a current mode, fixed frequency SEPIC/boost DC/DC converter with an internal 2A, 70V switch. Quiescent current of 7µA suits the device 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 1V to 60V, making it 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 to between 250 kHz and 1.5 MHz, enabling designers to minimise external component sizes. The combination of a thermally enhanced TSSOP-20E or 4 x 4 mm QFN package and small externals ensures a very compact footprint.

The internal 2A/70V switch delivers efficiencies of up to 83% while operating in a SEPIC configuration. A design using dual supply pins (VIN 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 (1,000). Industrial temperature (-40°C to 125°C) and high temperature (-40°C to 150°C) grades are also available.

Linear Technology; www.linear.com/product/LT8494