Hi All,

I am trying hard to understand buffers. This chapter says that weak signal is boosted by pair of inverters. http://www.allaboutcircuits.com/vol_4/chpt_3/3.html

how does pair of inverters boost a weak signal?

what does "weak" mean? what makes a signal weak?

how exactly buffers help in driving load?

I am trying to understand this for quite sometime and reading several books but no book seems to explain this clearly.
Regards,
Mark

 

Whatever is providing the "weak" signal has a certain limit on how much current it can source or sink while maintaining the voltage at a level that meets the requirements for a logic HI or LO. For instance, many logic gates can sink up to 20mA while maintaining a logic LO. But what if you needed to sink 50mA for your purposes? That signal is too weak. One option is to use a buffer that is capable of sinking at least 50mA and putting it between your signal and your load.