最近在看一篇講傳輸線的文章,裡面有這麼一張圖,拿來請教各位大蝦,文章內容如下
Diode termination prevents device damage or latch-up due to overshoots beyond the power rails, but it doesn’t terminate a transmission line’s Z0 properly. So the only significant EMC benefit from diode termination may be that they might help prevent transient damage as a result of a nearby electrostatic discharge (ESD).
圖上說用schottky diode,但schottky 能有預期的ESD保護作用嗎?ESD的上升沿可是只有1nS
再者,以圖示接法,是否表示要schottky逆向導通時才能保護到power rail上的transient damage?但schottky在正常使用條件下未順向導通前可以逆向導通嗎?schottky的逆向導通是可以被這樣應用的嗎?為何不用TVS?power rail 到傳輸線的這一顆保護元件改放在receiving device的VCC對GND 之間是否更理想? |