Green Design

Isolated Monolithic Flyback Regulator

Linear Technology Corporation (Milpitas, CA) offers a high-reliability (MP-grade) version of the LT3511, a high-voltage isolated monolithic flyback regulator that operates over a -55°C to 150°C junction temperature range. The device simplifies the design of an isolated DC/DC converter since it needs no optocoupler, third winding, or signal transformer for feedback, as the device’s output voltage is sensed from the primary-side flyback signal.

The LT3511 operates over a 4.5V to 100V input voltage range, has a 240mA, 150V onboard power switch and delivers up to 2.5 watts, making it well suited for a wide variety of telecom, datacom, automotive, industrial, and medical applications.

The LT3511 operates in a boundary mode, a current-mode control switching scheme, resulting in +/-5% typical 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.

(Linear Technology Corp)