| Author |
Message |
Taskuraha
Joined: 04 Jan 2003
Posts: 24
|
 25 Sep 2004 16:56 Diff amp |
|
|
|
| So i want to assure one thing about diff amps. If we have ordinary bjt diff amp. Does voltage difference between two base occur only ac-signal difference. So dc/bias voltage is same both transistors base, because bias current is I/2 for both transistor
|
|
| Back to top |
|
 |
krashkealoha
Joined: 03 Jul 2004
Posts: 101
Helped: 7
Location: 21.402, -157.739
|
| 25 Sep 2004 23:04 Re: Diff amp |
|
|
|
| An applied voltage difference on the base can be either AC or DC. Usually, if the input voltage difference is less than 3VT (~78mVpp) the diffamp stage is operating in the linear range. Input voltages greater than 3VT will fully switch one side of the diff pair, where >90% of the tail current will flow through the transistors, whose base is at the higher potential.
|
|
| Back to top |
|
|
khafaji
Joined: 28 Sep 2004
Posts: 19
Helped: 1
|
| 08 Oct 2004 22:55 Diff amp |
|
|
|
| Yes it is beeter that use the same DC bias for good result. also you can use different bias points but this not recommended
|
|
| Back to top |
|
|
