What is the use of bypass capacitors in (BJT)amplifier circuits?

Status
Not open for further replies.
D

Dineshkumar005

Newbie level 5
Joined
Jan 7, 2012
Messages
9
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Coimbatore
Activity points
1,355
Often, bypass capacitors which are labelled as Ce are used in amplifier circuits. What is their necessity and what is their function?
 

Ce is in parallel with Re.
Re fix the bias voltage at emitter.
this is DC. under ac signal conditions , Re is effectively shorted by the Ce , as its impedance will be zero at ac.
 
Ce is used when an emitter resistor Re is used to set the bias or the operating point. Re stabilizes the bias level by introducing negative feedback but also reduces signal amplification or gain. By bypassing Re with a capacitor, DC stability is unchanged but AC signal feedback and gain reduction is avoided.
 
Last edited:

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…