Why in unity gain bandwidth, gain refers to current gain not voltage?

Status
Not open for further replies.

sridhara

Member level 4
Joined
May 2, 2006
Messages
68
Helped
5
Reputation
10
Reaction score
2
Trophy points
1,288
Activity points
1,782
UGB= unity gain bandwidth where gain refers to current gain.....

my question why current gain and why not voltage gain.........
 

Re: unity gain bandwidth

Hi,
It is true, it all depends on which gain, current or voltage, we are talking about. In the case of transistor β, it refers to current gain and for an opamp open loop gain, it is in fact the voltage gain we refer to, by unity gain bandwidth.
Regards,
Laktronics
 

Re: unity gain bandwidth



sorry friend...it is current gain only and not voltage gain.....
 

Re: unity gain bandwidth

it is current gain only and not voltage gain
as a common BJT parameter, but not generally.
 

Re: unity gain bandwidth

Dear Friend

As you know this is a general aspect in measuring bandwidth in electronic so it strongly depends on which circuit of structure you are talking about. In operational amplifiers it is voltage gain but in some cases such as current conveyors it refers to current gain. Good luck
 

Re: unity gain bandwidth

As LK said the definition depends on the context. For transistor which is a current amplifier device the UGBW is the bw at unity current gain. For transistors this occurs when there is no injected carriers from the emitter and only the base recombination current accounts for the colector current. This is a critical condition for transistors and therefore the unity current gain BW is a significant parameter for transistor. For other devices like OPAMPs the open loop gain is always high and unity voltage gain is a common practical amplification with feedback. So the parameter may not be relevant to the OPAMPs.
 

Status
Not open for further replies.

Similar threads

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