# Design small signal midband common emitter amplifier bjt transistor

#### alyrajaie

Joined Nov 22, 2015
4
Hi all,
Could u all please help me to design common emmitter amplifier ( voltage divider config for dc analysis) which re the requirement as per follow:
1) beta = 160
2) vbe = 0.7
3) overall voltage gain (with load) =larger than 90
4) ac output signal vs = 50mV
5) source resistance Rs = 1K ohm
6) load resistance Rl = 2K ohm
7) -3db cut off freq
8) voltage supply dc (+5v) and (-5v)

I need to calculate all the resistors, capacitors, -3db cutt off freq, input resistance, output resistance, max voltage swing and the stage voltage gain...i also need to do the simulation to prove that calculated value..

#### DickCappels

Joined Aug 21, 2008
10,179
We won't do it for you but can offer advice. To get started, please show us what you have so far.

#### alyrajaie

Joined Nov 22, 2015
4
Tq sir..im appreciate this..Firstly....i have read some calculation to get the value of resistors and others..but i still confius how to het the value using data sheet....pls refer the attachments....tq so much....how to determine the min beta....ic...and so on using data sheet..

#### Attachments

• 277.7 KB Views: 19

#### Jony130

Joined Feb 17, 2009
5,488
But they give you the beta value, β = hfe = 160 and Vbe = 0.7V so you can start your designing process.

#### alyrajaie

Joined Nov 22, 2015
4
But they give you the beta value, β = hfe = 160 and Vbe = 0.7V so you can start your designing process.

#### Jony130

Joined Feb 17, 2009
5,488
Choosing the Ic current it up to designer.