Just like your credit cards, platinum trumps gold when it comes to ultra-fast high-voltage, medium-current diodes. The STTH series of diodes from STMicroelectronics is built with a planar, platinum-doped silicon process technology that helps optimize the combination of forward voltage drop (VF), leakage current (IR), and recovery time (tRR).
The principal advantage of the platinum doping is that it reduces leakage current by approximately 100 times compared to gold, providing scope to improve VF at a given tRR. A lower leakage current also helps with thermal runaway.
Optimizing VF in the new series cuts clamping-function power losses in standby mode. Also, the platinum process enables a 175°C maximum operating temperature.
The STTH diodes target applications that need ultra-fast diodes to handle voltages between 800 and 1200 V, but at relatively small currents. Such applications also require diodes with moderate recovery times (not more than 75 ns) and the best possible ratio of VF to IR.
There are five parts in the STTH family, with repetitive reverse voltage ratings from 800 to 1200 V and average forward current levels from 1 to 3 A. Unit prices range from $0.17 to $0.24 in quantities of 5000.