| 摘要 |
PURPOSE:To increase a protection function by employing a transistor as a substitute for a clamping diode. CONSTITUTION:For example, when a voltage much higher than power source Vcc is applied to output terminal Out through the induction of a relay coil, a current flowing from the emitter to base of transistor Q3 let transistor Q3 conduct to clamp collector potentials of transistors Q1 and Q2 for protection. Consequently, the occupation area of the clamping element in IC can be reduced. |
