Linear Technology Corporation announces a new military MP grade version of the LT3748, a high input voltage isolated flyback DC/DC controller. This device simplifies the design of an isolated DC/DC converter by not requiring an opto-isolator, third winding or signal transformer for feedback since the output voltage is sensed from the primary-side flyback signal. The LT3748 operates over a 5V to 100V input voltage range and drives an external N-channel power MOSFET, making it well suited for a wide variety of automotive, industrial, telecom and datacom applications.
The LT3748 operates in boundary mode, which is a variable frequency current mode control switching scheme, resulting in ±5% typical regulation over the full line, load and temperature range. Boundary mode also permits the use of a smaller transformer compared to equivalent continuous conduction mode designs. The output voltage is easily set by two external resistors and the transformer turns ratio. Several off-the-shelf transformers are identified in the data sheet that can be used for numerous applications. The high level of integration and the use of boundary mode operation results in a simple, clean application solution to the traditionally tough problem of isolated power delivery.
Additional features include an onboard low drop regulator for IC power, programmable soft start, undervoltage lockout, adjustable current limit and output voltage temperature compensation.
The LT3748MP operating junction temperature is from -55°C to 150°C and the device is housed in a MSOP-16 package with 4 pins removed for additional high voltage pin spacing. The 1,000 piece price starts at $9.25 each.