The Schottky diode may also be used as a clamp diode in a transistor circuit to speed the operation when used as a switch. The diode is inserted between the collector and base of the driver transistor to act as a clamp. To produce a low or logic "0" output the transistor is driven hard on, and in this situation the base collector junction in the diode is forward biased. When the Schottky diode is present this takes most of the current and allows the turn off time of the transistor to be greatly reduced, thereby improving the speed of the circuit.
An NPN transistor with Schottky diode clamp |
