Influence of pn junction surface region upon the peak pulse power of silicon transient voltage suppressors

It is shown that over 200-250 V nominal breakdown voltage, a premature junction surface breakdown at a voltage which is at least 50 V less than the bulk breakdown voltage value may appear. Such a suppressor is not able to withstand the expected value of the peak pulse power. If no premature breakdown occurs, the peak pulse power may be still affected by the surface component of the leakage current at high junction temperature. At nominal breakdown voltage lower than 200 V, less influence of the junction surface is exhibited on the suppressor power capability.