Isolated monolithic flyback regulator delivers up to 15 watts

November 14, 2013 // By Christoph Hammerschmidt
Development of DC/DC converters for automotive, industrial, medical, datacom and military can be simplified with the the LT8302 monolithic flyback regulator from Linear Technology.

By sampling the isolated output voltage directly from the primary-side flyback waveform, the part requires no opto-isolator or third winding for regulation. The LT8302 operates over a 2.8V to 42V input voltage range, has a 3.6A/65V power switch and delivers up to 15 Watts of output power.

The LT8302 operates in boundary mode, which is a variable frequency current-mode control switching scheme, typically resulting in +/-5% regulation over the full line, load and temperature range. Boundary mode enables the use of a smaller transformer compared to equivalent continuous conduction-mode designs. Output voltage can be set by two external resistors and the transformer turns ratio. Several off-the-shelf transformers, identified in the data sheet, can be used for numerous applications. The high level of integration and the use of low ripple Burst Mode operation result in a simple to use, low component count and high efficiency application solution for isolated power delivery.

Additional features include output short circuit protection, a 380µA no load quiescent current with the output voltage in regulation, internal soft start and compensation, along with output diode temperature compensation.

The LT8302 is available in a small thermally enhanced SO-8 package. Extended and industrial versions operate over a junction temperature range of –40°C to 125°C. A high temperature automotive grade operates from –40°C to 150°C and a military grade operates from

–55°C to 150°C.

For more information, visit www.linear.com/product/LT8302