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.

Time constant of an aluminum electrolytic capacitor

Status
Not open for further replies.

htg

Full Member level 5
Joined
May 1, 2010
Messages
248
Helped
5
Reputation
10
Reaction score
3
Trophy points
1,298
Location
Poland
Activity points
2,862
Can anyone tell me what is the order of magnitude of time constant of an aluminum electrolytic capacitor?
 

FvM

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
49,136
Helped
14,380
Reputation
29,024
Reaction score
13,134
Trophy points
1,393
Location
Bochum, Germany
Activity points
283,226
Which time constant? Self discharge time constant or charge/discharge time constant?
 

KlausST

Super Moderator
Staff member
Joined
Apr 17, 2014
Messages
20,800
Helped
4,496
Reputation
9,004
Reaction score
4,563
Trophy points
1,393
Activity points
137,345
Hi,

If I wanted to know this, then I'd look into the darasheet.
Maybe not every datasheet will show those values...then you need to find the correct datasheet.

Klaus
 

FvM

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
49,136
Helped
14,380
Reputation
29,024
Reaction score
13,134
Trophy points
1,393
Location
Bochum, Germany
Activity points
283,226
There's no single datasheet specification for leakage current (or leakage resistance respectively time constant), because leakage is voltage and temperature dependent, and also affected by the previous charge state, each in a non-linear manner.

For an rough estimation I would refer to the below given leakage current formula from an Epcos application note. The respective time constant is 2000 s (general purpose) or 4000 s (low leakage types).

Leakage.png
 

KlausST

Super Moderator
Staff member
Joined
Apr 17, 2014
Messages
20,800
Helped
4,496
Reputation
9,004
Reaction score
4,563
Trophy points
1,393
Activity points
137,345
Hi,

There's no single datasheet specification for leakage current
I did a google search: "al electrolytic capacitor datasheet".
I opened just the first three hits (TDK, Nichion, Panasonic) and every datasheet mentions leakage current.

It is true that leakage current depends on some parameters, therefore an exact value can't be given.
But it gives enough information to get a clue about leakage current behviour and it's expectable values.

Klaus
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top