This document describes the main features and characteristics of the STTH512 Ultrafast recovery - 1200 V diode. These features include ultrafast and soft recovery, very low conduction and switching losses, high frequency and/or high pulsed current operation, high reverse voltage capability, high junction temperature, etc. The diode has low leakage current, reproducible characteristics, and intrinsic ruggedness, making it ideal for heavy duty applications that require long term reliability. It is suitable for industrial power supplies, motor control, and similar mission-critical systems that require rectification and freewheeling. The diode can also be used in auxiliary functions such as snubber, bootstrap, and demagnetization applications. The improved performance in low leakage current and thermal runaway guard band is a competitive advantage for this device.