Simplified isolated DC/DC converter design, supports output up to 15W

Linear Technology is launching a new high-voltage monolithic flyback regulator that simplifies the design of isolated DC/DC converters.

The new product simplifies converter design by sampling the isolated output voltage reflected from the primary auxiliary winding of the power transformer. The new LT8315 operates over an input voltage range of 18V to 560V and features a built-in 0.30A/630V integrated power switch to provide up to 15W of output power, making it suitable for electric vehicles (EVs), battery stacks, offline, automotive, industrial, and medical applications.



The LT8315 operates in quasi-resonant boundary mode, a variable frequency current mode control switching principle, to improve load and line regulation to within ±1%. Boundary mode enables the use of smaller transformers compared to equivalent continuous current mode designs. The LT8315 not only offers high integration but also utilizes low-ripple burst mode operation to reduce component count, providing a high-efficiency application solution for isolated power supplies.

In addition, it supports output short-circuit protection, 70µA no-load standby current, undervoltage lockout (UVLO) with accurate enable and hysteresis, and output diode temperature compensation.

The LT8315 is available in a TSSOP-20 package with four pins removed for high-voltage isolation. The extended and industrial versions operate in a junction temperature range of –40°C to 125°C, while the automotive high-temperature grade product operates in a range of –40°C to 150°C.