P6KE16A 'transient voltage suppresor' - advice ?

[b]

I am working on a philips LCD tv with a broken psu. It was completely
dead and on opening it I found the usual story of bulging caps, signs
of overheating on the pcb thanks to the cramped vent-free design, etc
etc.
ZD 2 measures s/c, it is a P6KE16A, 16 volt 'transient voltage
suppresor' according to the datasheet here:
http://www.datasheetcatalog.org/datasheet/ShanghaiSunriseElectronics/mXuquwt.pdf

I'd like to know more about these components compared to a common-or-
garden zener. Apart from perhaps the faster protection action I'm not
clear on how they differ...
-B

 

[Shaun]

"b" <reverend_rogers@yahoo.com> wrote in message
news:84c040d0-f225-45ef-b8ab-1e3a152ca2d3@34g2000yqp.googlegroups.com...

I am working on a philips LCD tv with a broken psu. It was completely
dead and on opening it I found the usual story of bulging caps, signs
of overheating on the pcb thanks to the cramped vent-free design, etc
etc.
ZD 2 measures s/c, it is a P6KE16A, 16 volt 'transient voltage
suppresor' according to the datasheet here:
http://www.datasheetcatalog.org/datasheet/ShanghaiSunriseElectronics/mXuquwt.pdf

I'd like to know more about these components compared to a common-or-
garden zener. Apart from perhaps the faster protection action I'm not
clear on how they differ...
-B

Do a search on Wikipedia for TVS diode, that should give you some
information.

Shaun

 

[Franc Zabkar]

On Sat, 9 Jan 2010 17:51:48 -0600, "Shaun" <rowl@nomail.com> put
finger to keyboard and composed:

"b" <reverend_rogers@yahoo.com> wrote in message
news:84c040d0-f225-45ef-b8ab-1e3a152ca2d3@34g2000yqp.googlegroups.com...
I am working on a philips LCD tv with a broken psu. It was completely
dead and on opening it I found the usual story of bulging caps, signs
of overheating on the pcb thanks to the cramped vent-free design, etc
etc.
ZD 2 measures s/c, it is a P6KE16A, 16 volt 'transient voltage
suppresor' according to the datasheet here:
http://www.datasheetcatalog.org/datasheet/ShanghaiSunriseElectronics/mXuquwt.pdf

I'd like to know more about these components compared to a common-or-
garden zener. Apart from perhaps the faster protection action I'm not
clear on how they differ...
-B


Do a search on Wikipedia for TVS diode, that should give you some
information.

Shaun

What is a Silicon Transient Voltage Suppressor and how does it work?
http://www.vishay.com/docs/88436/appnote.pdf

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[N_Cook]

Franc Zabkar <fzabkar@iinternode.on.net> wrote in message
news:4vikk51drhr9r9egtf6d1ls55s7safdmsj@4ax.com...

On Sat, 9 Jan 2010 17:51:48 -0600, "Shaun" <rowl@nomail.com> put
finger to keyboard and composed:

"b" <reverend_rogers@yahoo.com> wrote in message
news:84c040d0-f225-45ef-b8ab-1e3a152ca2d3@34g2000yqp.googlegroups.com...
I am working on a philips LCD tv with a broken psu. It was completely
dead and on opening it I found the usual story of bulging caps, signs
of overheating on the pcb thanks to the cramped vent-free design, etc
etc.
ZD 2 measures s/c, it is a P6KE16A, 16 volt 'transient voltage
suppresor' according to the datasheet here:

http://www.datasheetcatalog.org/datasheet/ShanghaiSunriseElectronics/mXuquwt

..pdf

I'd like to know more about these components compared to a common-or-
garden zener. Apart from perhaps the faster protection action I'm not
clear on how they differ...
-B


Do a search on Wikipedia for TVS diode, that should give you some
information.

Shaun

What is a Silicon Transient Voltage Suppressor and how does it work?
http://www.vishay.com/docs/88436/appnote.pdf

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

But,unlike zeners , are they guaranteed to go short circuit if they end up
in what becomes a sustained overvoltage rather than just a transient
situation ? or 2 different clases of VTS ?

 

[Franc Zabkar]

On Mon, 11 Jan 2010 08:25:42 -0000, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

But,unlike zeners , are they guaranteed to go short circuit if they end up
in what becomes a sustained overvoltage rather than just a transient
situation ? or 2 different clases of TVS ?

I watch various hard drive forums. HDs nowadays use TVS diodes on
their +5V and +12V rails. A sustained overvoltage from, say, a 19V
laptop adapter always (?) shorts the 12V diode, unless it is protected
by a fusible zero-ohm resistor.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[N_Cook]

Franc Zabkar <fzabkar@iinternode.on.net> wrote in message
news:giolk5pi2o49ioli9lodfte4magsnsv34e@4ax.com...

On Mon, 11 Jan 2010 08:25:42 -0000, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

But,unlike zeners , are they guaranteed to go short circuit if they end
up
in what becomes a sustained overvoltage rather than just a transient
situation ? or 2 different clases of TVS ?

I watch various hard drive forums. HDs nowadays use TVS diodes on
their +5V and +12V rails. A sustained overvoltage from, say, a 19V
laptop adapter always (?) shorts the 12V diode, unless it is protected
by a fusible zero-ohm resistor.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

A zener would normally burn up/ go open circuit in overvoltage but do VTS
normally (but not guaranteed) go short thus providing crowbar protection if
fuse/fusible R/ current limiting/ps shut down, upstream. 80 percent/90
percent/ 99 percent of the time go s/c rather than o/c , any
guesses/knowlege?

 

[N_Cook]

And for completeness, in general terms.
I know it must vary with manufacturer/type of overload (eg from repeated
short term overloads/various amount of one-off overload, surges rather than
transients etc)
I think I've only ever come across 3 failed VTS, all s/c, so 80 percent
failing s/c , generally say
Over the years I would , gut-feeling , say zeners fail o/c 80 percent of the
time.
Anyone else's experiences to add here for a concensus view from experience?

 

[N_Cook]

Some interesting failure mode comparisons on this ap note
www.littelfuse.com/data/en/Application_Notes/an9768.pdf

 

[Franc Zabkar]

On Mon, 11 Jan 2010 08:55:58 -0000, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

Franc Zabkar <fzabkar@iinternode.on.net> wrote in message
news:giolk5pi2o49ioli9lodfte4magsnsv34e@4ax.com...
On Mon, 11 Jan 2010 08:25:42 -0000, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

But,unlike zeners , are they guaranteed to go short circuit if they end
up
in what becomes a sustained overvoltage rather than just a transient
situation ? or 2 different clases of TVS ?

I watch various hard drive forums. HDs nowadays use TVS diodes on
their +5V and +12V rails. A sustained overvoltage from, say, a 19V
laptop adapter always (?) shorts the 12V diode, unless it is protected
by a fusible zero-ohm resistor.

- Franc Zabkar

A zener would normally burn up/ go open circuit in overvoltage but do VTS
normally (but not guaranteed) go short thus providing crowbar protection if
fuse/fusible R/ current limiting/ps shut down, upstream. 80 percent/90
percent/ 99 percent of the time go s/c rather than o/c , any
guesses/knowlege?

I would think that they would go s/c, but will eventually go o/c if
the fault current is sustained.

The TVS failures I've seen have all been s/c because the PSU has shut
down.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Shaun]

"b" <reverend_rogers@yahoo.com> wrote in message
news:f3650d2f-992f-4ec2-8625-a459270627c1@u7g2000yqm.googlegroups.com...

On 11 ene, 20:48, Franc Zabkar <fzab...@iinternode.on.net> wrote:
On Mon, 11 Jan 2010 08:55:58 -0000, "N_Cook" <dive...@tcp.co.uk> put
finger to keyboard and composed:



Franc Zabkar <fzab...@iinternode.on.net> wrote in message
news:giolk5pi2o49ioli9lodfte4magsnsv34e@4ax.com...
On Mon, 11 Jan 2010 08:25:42 -0000, "N_Cook" <dive...@tcp.co.uk> put
finger to keyboard and composed:

But,unlike zeners , are they guaranteed to go short circuit if they
end
up
in what becomes a sustained overvoltage rather than just a transient
situation ? or 2 different clases of TVS ?

I watch various hard drive forums. HDs nowadays use TVS diodes on
their +5V and +12V rails. A sustained overvoltage from, say, a 19V
laptop adapter always (?) shorts the 12V diode, unless it is protected
by a fusible zero-ohm resistor.

- Franc Zabkar
A zener would normally burn up/ go open circuit in overvoltage but do
VTS
normally (but not guaranteed) go short thus providing crowbar protection
if
fuse/fusible R/ current limiting/ps shut down, upstream. 80 percent/90
percent/ 99 percent of the time go s/c rather than o/c , any
guesses/knowlege?

I would think that they would go s/c, but will eventually go o/c if
the fault current is sustained.

The TVS failures I've seen have all been s/c because the PSU has shut
down.


thanks for all the replies. so, seems like this is purely for
protection while zeners can be sued for regulation.
the one here is s/c and the psu was utterly dead. there are a few
bulged caps and its a cramped crappy design so no real mystery. it
must have gone s/c as the rails crept up and it could no longer handle
the suppression of transients. Owner reported strange noises before it
died.
-B

Hello B,

Here's a description for TVS diodes that talk about the difference between
them and zeners.

http://www.semtech.com/images/datasheet/what_are_tvs_diodes.pdf

Shaun

 

[b]

On 11 ene, 20:48, Franc Zabkar <fzab...@iinternode.on.net> wrote:

On Mon, 11 Jan 2010 08:55:58 -0000, "N_Cook" <dive...@tcp.co.uk> put
finger to keyboard and composed:



Franc Zabkar <fzab...@iinternode.on.net> wrote in message
news:giolk5pi2o49ioli9lodfte4magsnsv34e@4ax.com...
On Mon, 11 Jan 2010 08:25:42 -0000, "N_Cook" <dive...@tcp.co.uk> put
finger to keyboard and composed:

But,unlike zeners , are they guaranteed to go short circuit if they end
up
in what becomes a sustained overvoltage rather than just a transient
situation ? or 2 different clases of TVS ?

I watch various hard drive forums. HDs nowadays use TVS diodes on
their +5V and +12V rails. A sustained overvoltage from, say, a 19V
laptop adapter always (?) shorts the 12V diode, unless it is protected
by a fusible zero-ohm resistor.

- Franc Zabkar
A zener would normally burn up/ go open circuit in overvoltage but do VTS
normally (but not guaranteed) go short thus providing crowbar protection if
fuse/fusible R/ current limiting/ps shut down, upstream. 80 percent/90
percent/ 99 percent of the time go s/c rather than o/c , any
guesses/knowlege?

I would think that they would go s/c, but will eventually go o/c if
the fault current is sustained.

The TVS failures I've seen have all been s/c because the PSU has shut down.

thanks for all the replies. so, seems like this is purely for
protection while zeners can be sued for regulation.
the one here is s/c and the psu was utterly dead. there are a few
bulged caps and its a cramped crappy design so no real mystery. it
must have gone s/c as the rails crept up and it could no longer handle
the suppression of transients. Owner reported strange noises before it
died.
-B

 

[b]

Another question: what do the suffixes 'A' or 'CA' refer to? I ask
because I have been unable to find the exact replacement but have a
P6KE20CA. Not ideal, since the voltage rathing is 4v higher but I
assume it's better than nothing. Or would this be a bad idea due to
the different suffix?
cheers.
-B

 

[JeffM]

b wrote:

what do the suffixes 'A' or 'CA' refer to?

http://google.com/search?q=transorb+%22+suffix-A-denotes-*-*%22+%22+suffix-CA-denotes-*-*

 

[N_Cook]

JeffM <jeffm_@email.com> wrote in message
news:331bff15-4036-4de7-9b3b-2d59aa1bd249@b2g2000yqi.googlegroups.com...

b wrote:
what do the suffixes 'A' or 'CA' refer to?


http://google.com/search?q=transorb+%22+suffix-A-denotes-*-*%22+%22+suffix-C

A-denotes-*-*


But what is the function of
*-*
in the search string ?

 

[JeffM]

b wrote:
what do the suffixes 'A' or 'CA' refer to?

JeffM wrote:
http://google.com/search?q=transorb+%22+suffix-A-denotes-*-*%22+%22+suffix-CA-denotes-*-*

N_Cook wrote:
But what is the function of *-* in the search string ?

Wildcards. Google (alone, AFAIK) allows those.

When the results page appears, the words that appear in the phrase
where the asterisks are[1] will be highlighted
(along with the requested text).

....and, of course, the day after I post the link,
Google stops indexing the page. 8-(

Note also that when properly rendered on a schematic,
a CA device will have a nose-to-nose symbol reprentation.
..
..
[1] A hyphen is a valid word separator (as is a period).

 

[b]

so far I've been unable to find the part in question. As I need to
return this unit soon, I'm loath to leave it without some form of o/p
protection, is there anything strightforward I could add to this psu
to protect the appliance 'downstream'? possibly some form of crowbar
at least.
-B

 

[circuit]

Plenty of them in stock :

http://www.mouser.com/Search/Refine.aspx?Keyword=P6KE16A

No minimum order , but I dont know if they do international orders.





"b" <reverend_rogers@yahoo.com> wrote in message
news:b991a069-2b09-46ea-b7b8-3ccaf9cf02e9@t23g2000yqt.googlegroups.com...

so far I've been unable to find the part in question. As I need to
return this unit soon, I'm loath to leave it without some form of o/p
protection, is there anything strightforward I could add to this psu
to protect the appliance 'downstream'? possibly some form of crowbar
at least.
-B

 

[JeffM]

b wrote:

I've been unable to find the part in question.

This describes Igor's Spam-Free Custom Search:

http://groups.google.com/group/sci.electronics.design/browse_frm/thread/5266f3e66e3279dc?q=search.results+contribute+Search.without.spammers+EXCLUDED+worthless-asshole-spammers+Google.custom.search
You should bookmark the Google page.

Not only did it find the item,
4 entities thought it was worthwhile to pay for an ad for that term.