March 19, 2015 – Linear Technology Korea (CEO Hong Sa-gwak) has announced the release of the LT3748, a high input voltage isolated flyback DC/DC controller in a new military-grade MP version. This device simplifies DC/DC converter design by sensing the output voltage from the primary-side flyback signal, thereby eliminating the need for optoisolators, tertiary windings, or feedback circuitry for regulation. The LT3748 operates across an input voltage range of 5V to 100V and drives an external N-channel power MOSFET, making it ideal for automotive, industrial, telecom, and datacom applications.

The LT3748 operates in boundary mode, a variable frequency current-mode control switching circuit that delivers typical regulation of ±5% across the entire line, load, and temperature range. Boundary mode enables the use of smaller transformers compared to equivalent continuous conduction mode (CCM) designs. The output voltage can be easily set using two external resistors and the transformer turns ratio. Several ready-to-use transformers are available in the datasheet for numerous applications. The high level of integration and use of boundary mode operation provide simple and elegant application solutions to traditionally challenging issues in isolated power supplies.

Additional features include an onboard low-dropout regulator for IC power, programmable soft start, low voltage lockout, adjustable current limit, and output voltage temperature compensation.

The LT3748MP operating junction temperature ranges from –55°C to 150°C, and the device is packaged in a 4-pin MSOP-16 package, eliminating additional high-voltage pin space. Pricing is $9.25 per unit in 1,000-unit quantities. For more information, refer to www.linear.com/product/LT3748.

Photo Caption: 100V Isolated Flyback Operating at –55°C ~ 150°C

Product Features: LT3748MP

· Operating junction temperature of –55°C to 150°C

· VIN range: 5V to 100V

· No optoisolators, transformers, or tertiary windings required for feedback

· Drives external N-channel power MOSFET

· Current mode control

· Boundary mode operation

· VOUT set with two external resistors

· Ready-to-use transformers

· Programmable soft start

· Programmable low voltage lockout

· Output voltage temperature compensation

USA list pricing information is provided for rough budgeting purposes, and international pricing may vary depending on regional tariffs, taxes, fees, and exchange rates.