怎样提高放大器的dynamic range?

DukeLeon

设计了一个级联放大器，基本单元就是双输入，双输出的差分放大器，但是，输出一旦振幅超过100mV，就开始有一定程度的失真。如果输入电压增大到一个值，输出就会彻底失真，有没有什么办法可以提高voltage output swing的？

iamxo

那就只有提高电源电压了。

DukeLeon

原帖由 iamxo 于 2009-7-12 08:55 发表

                               
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那就只有提高电源电压了。

Is there any other methods? It is just very basic differential amp with diode-connected load.

vdslafe

原帖由 DukeLeon 于 2009-7-12 09:11 发表

                               
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Is there any other methods? It is just very basic differential amp with diode-connected load.

Open loop amp?
resistor load will help

DukeLeon

原帖由 vdslafe 于 2009-7-12 09:18 发表

                               
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Open loop amp?
resistor load will help

yes, open loop
resistor is not desirable, since the fabrication variation, the real value of resistor will be different, so for the next stage, the DC input level of the differential pairs would be different.
On the other hand, because the package parasitic, it is also not desirable to use off-chip resistor.
It seems that there is not other good methods to enhance the output swing by means of this simple differential amp. Anyway, disctortion is also acceptable maybe. Thanks all the same.