Overloading in Amplifiers

[iVenky]

Here's a sentence taken from Malvino book

"When the load resistance is small compared to the collector resistance, the voltage gain of a CE stage becomes small and the amplifier may become overloaded."

I understand that when the load resistance decreases, the voltage gain decreases. Also I understand that it is necessary to have a small output impedance compared to the load so that the entire voltage gets dropped across the load.
But what do you mean by "amplifier become overloaded"?

Thanks in advance.

 

[goldsmith]

Dear iVenky
Hi
It means that when you decrease the load , your amplifier can't supply , the load current , thus , it means that your load is improper .
Best Wishes
Goldsmith

 

[iVenky]

Hello Goldsmith. I know that it can't supply the load voltage but I think it can supply the load current as higher the output impedance higher the load current.

 

[goldsmith]

Don't forget that why the voltage dropped . consider that we have a current source , it can't give you the currents more than authorized current . right ? after that the voltage of that current source will decrease , right ? because it can't give currents more than that value . i think now it is clear . isn't it ?
Best Wishes
Goldsmith

 

[iVenky]

I understand that, yet the output current is not affected.

According to you it looks as if the output current remains same and independent of resistance?

Only the output voltage is getting affected.

 

[FvM]

"When the load resistance is small compared to the collector resistance, the voltage gain of a CE stage becomes small and the amplifier may become overloaded."

Without any further explanation, I won't try to read a sense into these words. If the discussion is e.g. about an amplifier with voltage controlled feedback, that tries to keep the output voltage constant, you should mentions it. An open loop CE stage won't get overloaded by reducing the load resistance, rather by increasing it.