100-V isolated monolithic flyback regulator focuses on high reliability applications

September 16, 2011 // By Paul Buckley
Linear Technology Corporation has introduced the high reliability (MP-grade) version of the LT3512, a high voltage isolated monolithic flyback regulator that operates over a -55 to 150 °C junction temperature range. The device simplifies the design of an isolated DC/DC converter.

The LT3512 requires no optocoupler, third winding or signal transformer for feedback, as the device’s output voltage is sensed from the primary-side flyback signal.

The LT3512 operates over a 4.5 V to 100 V input voltage range, has a 420 mA, 150 V power switch and delivers up to 4.5 W of output power, making it well suited for a wide variety of telecom, datacom, automotive, industrial and military applications.

The LT3512 operates in a boundary mode, current-mode control switching scheme, resulting in less than ±5% regulation over the full line, load and temperature range. Boundary mode, also known as critical conduction mode (crcm), 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 transformers identified in the data sheet can be used for numerous applications. The device’s high level of integration results in a simple, clean, tightly regulated application solution to the traditional challenge of isolated power delivery.

The LT3512MP is available in a small MSOP-16 package with 4 pins removed for additional high voltage pin spacing.

More information about the LT3512MP monolithic flyback regulator at www.linear.com/product/LT3512MP.