Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Class A PA PAE with resistive load & inductor load

Status
Not open for further replies.

MI3talk

Junior Member level 3
Joined
Mar 29, 2007
Messages
27
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,281
Activity points
1,448
Class A PA PAE with resistive load & inductor load quest


--------------------------------------------------------------------------------

Hi all,

I think I have a dumb question to ask.

over couple of days, I was trying to understand why Resistive load Class A PAE is 25% and Class A with Inductive load is 50%.

It was told that inductor can swing rail to rail, but why? It that because the current direction could go from 0 to positive rail and back down to 0 and swing to negative rail again?

Can someone please explain in details with load line analysis?
 

vfone

Advanced Member level 5
Joined
Oct 10, 2001
Messages
5,350
Helped
1,553
Reputation
3,109
Reaction score
1,166
Trophy points
1,393
Activity points
33,901
The efficiency of Class-A Power Amplifier is degraded by the on-state resistance or saturation voltage of the transistor. It is also degraded by the presence of load reactance, which actually requires the PA to generate more output voltage or current to deliver the same power to the load.
 

BigBoss

Advanced Member level 5
Joined
Nov 17, 2001
Messages
5,117
Helped
1,529
Reputation
3,056
Reaction score
1,376
Trophy points
1,393
Location
Turkey
Activity points
30,772
Load line with inductive (or capacitivie) is not a straight line but ellipse..( depending on reactance value)
Therefore current that flows thru load is not purely real instead reactive so some power returns back to the amplifier even tough the amplifier is well matched.
In addition to, there will be some additional mismatch (in terms of power ) and that's why load is not fully delivered to the load..

It should be prevent to use reactive loads..
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top