High Power Pin Diode Switching Circuitry With Built-In Short Circuit Protection

In high power diode switching applications where overdrive is necessary, it is difficult to incorporate a short circuit feature in the driving circuitry. In this paper, a high power PIN diode driver with built-in protecting network based on a self-timing mode is described. The self-timing network is monitoring the output voltage and if a short exists, after a reverse-bias switching is completed, it acts to deviate the base current from the output driving device and reduces the load current by a few orders of magnitude. During every forward-bias to reverse-bias transition, the timing network introduces a delay to avoid interference with the normal operation of the circuit. The described driving circuit is suitable in systems where a plurality of such drivers may be used or in testing instrumentation.