Date: 09/02/2010

Low power switching regulator from Linear for isolated power supply apps

Linear has introduced the LT3574, a new isolated monolithic flyback switching regulator that simplifies the design of a low power isolated DC/DC converter. The LT3574 regulator is suitable for industrial, medical, telecom, datacom and automotive applications.

The key features of the LT3574 regulator are,

Operating input voltage ranges from 3V to 40V
0.65A, 60V integrated NPN power switch and can deliver up to 3 watts of output power
Boundary mode operation
No transformer third winding or opto-isolator required for regulation
Improved primary-side winding feedback load regulation
VOUT set with two external resistors
BIAS pin for internal bias supply and power NPN driver
Programmable soft-start, undervoltage lockout
Output voltage temperature compensation
Programmable power switch current limit

The LT3574 regulator does not require opto-isolator, third winding or signal transformer for feedback since the output voltage is sensed from the primary-side flyback signal. The LT3574 operates in boundary mode, which is a variable frequency current mode control-switching scheme, resulting in +/-5% regulation over the full line, load and temperature range. Boundary mode also permits the use of a small transformer compared to equivalent continuous conduction mode designs.

Two external resistors and the transformers turns ratio easily set the output voltage. The high level of integration and use of boundary mode operation results in a simple, clean application solution to the tough problem of isolated power delivery.

Package: 16-Lead MSOP package
Price: Each $2.76 for 1k pieces
Availability: Now

For more details visit www.linear.com