LT3748 - 100V Isolated Flyback DC/DC Controller

sleuz — Sun, 27 Oct 2013 02:57:11 GMT

Current Revision posted to Documents by sleuz on 10/27/2013 2:57:11 AM

100V Isolated Flyback DC/DC Controller Simplifies Design & Eliminates Optocoupler

V_INRange from 5V to 100V
No Opto-Isolator, Transformer or Third Winding Required for Feedback
Drives External N-channel Power MOSFET
Current Mode Control
Boundary Mode Operation
V_OUT Set with Two External Resistors
Off-the-Shelf Transformers
Programmable Soft-Start
Programmable Undervoltage Lockout
Output Voltage Temperature Compensation

The LT3748LT3748 is a high input voltage isolated flyback DC/DC controller that significantly simplifies the design of an isolated DC/DC converter. No opto-isolator, third winding or signal transformer is required for feedback since the output voltage is sensed from the primary-side flyback signal. The LT3748LT3748 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 industrial, medical, telecom, datacom and automotive applications.

LT3748 Schematic

The LT3748LT3748 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 identified in the data sheet 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 dropout regulator for IC power, programmable soft-start, undervoltage lockout, adjustable current limit and output voltage temperature compensation. The LT3748LT3748 is available in a small MSOP-16 package with 4 pins removed for additional high voltage pin spacing.

More info on www.linear.com/3748 or go to Design Kit Demoboard

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Attachments:

community.element14.com/.../1641.LTspice_5F00_Quick_5F00_Start.pdf	LTspice_Quick_Start.pdf
community.element14.com/.../4377.WE_5F00_Library_5F00_LTspice.zip

Tags: communications, wuerth, components, igbt_controller, loop, emv, emc, custom, lamps, passive, no_aging, würth, isolation, Design, flash, voltage, led_lighting, feedback, poe, xenon, elektronik, electromechanical, no_optocoupler, transformers, supply, Easy, voice_over_ip, standard, wurth_elektronik