Help identifying Motorola diode.

[gcd]

Hi all,
I'm trying to identify a Motorola surface mount diode.

The code on the didoe is 607 with a datecode of 9318. It's a Motorola from
the logo. I've not had success with google trying to find it, would anyone
have any ides? I think it's azener, or perhaps a schottky.

Thanks
Greg
(sorry if this posts a second time, tpg doesn't seem to post out)

 

[Bob Milutinovic]

"gcd" <gcddeletemelbnospam@melbnospam.iimetro.com.au> wrote in message
news:i4GdnUA6yuIsTWnMnZ2dnUVZ_uudnZ2d@westnet.com.au...

Hi all,
I'm trying to identify a Motorola surface mount diode.

The code on the didoe is 607 with a datecode of 9318. It's a Motorola from
the logo. I've not had success with google trying to find it, would anyone
have any ides? I think it's azener, or perhaps a schottky.

Thanks
Greg
(sorry if this posts a second time, tpg doesn't seem to post out)

I can find a Motorola reference referring to their 1N607 and 1N607a diodes,
which the reference states can be replaced with a 1N4001 - far from a Zener!
Whether the "607" on your device refers to 1N607 or something entirely
different though, is anyone's guess.

The reference sheet's here; click the thumbnail to download the PDF -
http://www.datasheetarchive.com/dataframe.php?file=DSA8580006665.pdf&dir=Datasheets-X1&part=1N607

You might want to contact WES in Ashfield (Sydney) and ask for their
thoughts; though I haven't dealt with them in several years, I remember
their staff being very knowledgable.

--
Bob Milutinovic
Cognicom

 

[Phil Allison]

"gcd"

I'm trying to identify a Motorola surface mount diode.

The code on the didoe is 607 with a datecode of 9318. It's a Motorola from
the logo. I've not had success with google trying to find it, would anyone
have any ides? I think it's azener, or perhaps a schottky.

** Why not test it - if it still functioning.



.... Phil

 

[gcd]

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:b5m5qpF8brtU1@mid.individual.net...

"gcd"

I'm trying to identify a Motorola surface mount diode.

The code on the didoe is 607 with a datecode of 9318. It's a Motorola
from the logo. I've not had success with google trying to find it, would
anyone have any ides? I think it's azener, or perhaps a schottky.


** Why not test it - if it still functioning.



... Phil

Hi,
I'm reasonably sure it's damaged.

I didn't reverse engineer enough of the circuit and found this diode
directly across a filter cap after a 2 diode rectifier in a smps after it
heated enough to melt the solder on the board. (wound the external supply
up to 15V with 100-150mA current limit set).

So the diode now measures around 0.7V forward and breaks down at around
17-18v.

In the circuit it's directly across the filter cap with no current limit
resistor so I've either damaged a 15v zener or I've damaged a 15v schottky
that was there for some unknon reason.

I've checked all the smd code websites and pdf that I can find but no
reference to a motorola diode with code 607.

I'd suspect a 15V zener but I'm loathed to put one in there with no
resistor. The smps circuit maintains it's fault without the diode, so I can
still do some fault finding.

Greg

 

[gcd]

"Bob Milutinovic" <cognicom@gmail.com> wrote in message
news:kt3esv$i32$1@dont-email.me...

"gcd" <gcddeletemelbnospam@melbnospam.iimetro.com.au> wrote in message
news:i4GdnUA6yuIsTWnMnZ2dnUVZ_uudnZ2d@westnet.com.au...
Hi all,
I'm trying to identify a Motorola surface mount diode.

The code on the didoe is 607 with a datecode of 9318. It's a Motorola
from the logo. I've not had success with google trying to find it, would
anyone have any ides? I think it's azener, or perhaps a schottky.

Thanks
Greg
(sorry if this posts a second time, tpg doesn't seem to post out)

I can find a Motorola reference referring to their 1N607 and 1N607a
diodes, which the reference states can be replaced with a 1N4001 - far
from a Zener! Whether the "607" on your device refers to 1N607 or
something entirely different though, is anyone's guess.

The reference sheet's here; click the thumbnail to download the PDF -
http://www.datasheetarchive.com/dataframe.php?file=DSA8580006665.pdf&dir=Datasheets-X1&part=1N607

You might want to contact WES in Ashfield (Sydney) and ask for their
thoughts; though I haven't dealt with them in several years, I remember
their staff being very knowledgable.

--
Bob Milutinovic
Cognicom

Hi,

no it's not a 1N400x type didoe, it wouldn't have broken down at around 15v.
See my reply to Phil, I expect it's a 15v Zener. Also, looks like the 1N607
is a DO-4 case style, not an SMA or SMC surface mount type case.

Thanks
Greg

 

[Andy Wood]

"gcd" <gcddeletenospam@melbnospam.iimetro.com.au> wrote:

.. . .

So the diode now measures around 0.7V forward and breaks down at around
17-18v.

In the circuit it's directly across the filter cap with no current limit
resistor so I've either damaged a 15v zener or I've damaged a 15v schottky
that was there for some unknon reason.

Transient suppressor maybe?

Did you try searching for Onsemi instead of Motorola?


Andy Wood
woodag@trap.ozemail.com.au

 

[Phil Allison]

"gcd"

"Phil Allison"
I'm trying to identify a Motorola surface mount diode.

The code on the didoe is 607 with a datecode of 9318. It's a Motorola
from the logo. I've not had success with google trying to find it, would
anyone have any ides? I think it's azener, or perhaps a schottky.


** Why not test it - if it still functioning.


I'm reasonably sure it's damaged.

I didn't reverse engineer enough of the circuit and found this diode
directly across a filter cap after a 2 diode rectifier in a smps after it
heated enough to melt the solder on the board. (wound the external supply
up to 15V with 100-150mA current limit set).

So the diode now measures around 0.7V forward and breaks down at around
17-18v.

In the circuit it's directly across the filter cap with no current limit

** SMPS often have sacrificial zeners across DC outputs.

When the PSU goes haywire and the DC voltage rises out of control, it fails
short and prevents harm to the attached load.

A crude crow-bar circuit, in fact.


.... Phil

 

[gcd]

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:b5omplFp71sU1@mid.individual.net...

"gcd"
"Phil Allison"
I'm trying to identify a Motorola surface mount diode.

The code on the didoe is 607 with a datecode of 9318. It's a Motorola
from the logo. I've not had success with google trying to find it,
would anyone have any ides? I think it's azener, or perhaps a schottky.


** Why not test it - if it still functioning.


I'm reasonably sure it's damaged.

I didn't reverse engineer enough of the circuit and found this diode
directly across a filter cap after a 2 diode rectifier in a smps after it
heated enough to melt the solder on the board. (wound the external supply
up to 15V with 100-150mA current limit set).

So the diode now measures around 0.7V forward and breaks down at around
17-18v.

In the circuit it's directly across the filter cap with no current limit

** SMPS often have sacrificial zeners across DC outputs.

When the PSU goes haywire and the DC voltage rises out of control, it
fails short and prevents harm to the attached load.

A crude crow-bar circuit, in fact.


... Phil

zener it is then, wasn't aware that such techniques would be used,
particularily as this smps is form a rather expensive hf receiver.

thanks
Greg

 

[Ian Field]

"gcd" <gcddeletenospam@melbnospam.iimetro.com.au> wrote in message
news:UvadnSmZwNcOqGvMnZ2dnUVZ_h-dnZ2d@westnet.com.au...

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:b5m5qpF8brtU1@mid.individual.net...

"gcd"

I'm trying to identify a Motorola surface mount diode.

The code on the didoe is 607 with a datecode of 9318. It's a Motorola
from the logo. I've not had success with google trying to find it, would
anyone have any ides? I think it's azener, or perhaps a schottky.


** Why not test it - if it still functioning.



... Phil


Hi,
I'm reasonably sure it's damaged.

I didn't reverse engineer enough of the circuit and found this diode
directly across a filter cap after a 2 diode rectifier in a smps after it
heated enough to melt the solder on the board. (wound the external supply
up to 15V with 100-150mA current limit set).

So the diode now measures around 0.7V forward and breaks down at around
17-18v.

Sounds like maybe a zener, while regular diodes can drop as much as 1.1V at
max rated current, 0.7V is regarded as "nominal". In actual fact; a DMM
diode check is likely to show nearer 0.65V (even lower for fast diodes) -
the diode check will actually show 0.7V on a zener.

Shottky-barrier diodes vary considerably depending on current rating, I've
measured as low as 0.1V for big stud mounted rectifiers, and (I think) about
0.4V for the likes of a 1N5817 etc.

The low reverse breakdown adds credibility to the idea of it being a zener.

 

[Ian Field]

"gcd" <gcddeletenospam@melbnospam.iimetro.com.au> wrote in message
news:kLKdnW4nIY2cyGHMnZ2dnUVZ_vednZ2d@westnet.com.au...

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:b5omplFp71sU1@mid.individual.net...

"gcd"
"Phil Allison"
I'm trying to identify a Motorola surface mount diode.

The code on the didoe is 607 with a datecode of 9318. It's a Motorola
from the logo. I've not had success with google trying to find it,
would anyone have any ides? I think it's azener, or perhaps a
schottky.


** Why not test it - if it still functioning.


I'm reasonably sure it's damaged.

I didn't reverse engineer enough of the circuit and found this diode
directly across a filter cap after a 2 diode rectifier in a smps after
it heated enough to melt the solder on the board. (wound the external
supply up to 15V with 100-150mA current limit set).

So the diode now measures around 0.7V forward and breaks down at around
17-18v.

In the circuit it's directly across the filter cap with no current
limit

** SMPS often have sacrificial zeners across DC outputs.

When the PSU goes haywire and the DC voltage rises out of control, it
fails short and prevents harm to the attached load.

A crude crow-bar circuit, in fact.


... Phil


zener it is then, wasn't aware that such techniques would be used,
particularily as this smps is form a rather expensive hf receiver.

Phil is probably right with "crude crow-bar" - the not so cheap & nasty
version uses a zener (taking Vgate into account) to latch a SCR across the
rail, a fuse is pretty much essential.

 

[gcd]

"Ian Field" <gangprobing.alien@ntlworld.com> wrote in message
news:YkTLt.3854$9R3.397@fx23.am4...

"gcd" <gcddeletenospam@melbnospam.iimetro.com.au> wrote in message
news:UvadnSmZwNcOqGvMnZ2dnUVZ_h-dnZ2d@westnet.com.au...

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:b5m5qpF8brtU1@mid.individual.net...

"gcd"

I'm trying to identify a Motorola surface mount diode.

The code on the didoe is 607 with a datecode of 9318. It's a Motorola
from the logo. I've not had success with google trying to find it,
would anyone have any ides? I think it's azener, or perhaps a schottky.


** Why not test it - if it still functioning.



... Phil


Hi,
I'm reasonably sure it's damaged.

I didn't reverse engineer enough of the circuit and found this diode
directly across a filter cap after a 2 diode rectifier in a smps after it
heated enough to melt the solder on the board. (wound the external supply
up to 15V with 100-150mA current limit set).

So the diode now measures around 0.7V forward and breaks down at around
17-18v.

Sounds like maybe a zener, while regular diodes can drop as much as 1.1V
at max rated current, 0.7V is regarded as "nominal". In actual fact; a DMM
diode check is likely to show nearer 0.65V (even lower for fast diodes) -
the diode check will actually show 0.7V on a zener.

Shottky-barrier diodes vary considerably depending on current rating, I've
measured as low as 0.1V for big stud mounted rectifiers, and (I think)
about 0.4V for the likes of a 1N5817 etc.

The low reverse breakdown adds credibility to the idea of it being a
zener.
Hi,

the 15V breakdown also made me consider the schottky, that's a typical
schottky breakdown voltage.
But a zener sounds more logical than a schottky. However such a brute force
approach is likley to cause collateral daamge within the smps than something
more elegant.

Cheers
Greg

 

[Phil Allison]

"gcd"

Hi,
the 15V breakdown also made me consider the schottky, that's a typical
schottky breakdown voltage.

** Like hell it is.

But a zener sounds more logical than a schottky.

** Wired in parallel with an electro - of course it's a zener.



.... Phil

 

[Ian Field]

"gcd" <gcddeletenospam@melbnospam.iimetro.com.au> wrote in message
news:EOydnQLEjsLSOZ3PnZ2dnUVZ_uednZ2d@westnet.com.au...

"Ian Field" <gangprobing.alien@ntlworld.com> wrote in message
news:YkTLt.3854$9R3.397@fx23.am4...


"gcd" <gcddeletenospam@melbnospam.iimetro.com.au> wrote in message
news:UvadnSmZwNcOqGvMnZ2dnUVZ_h-dnZ2d@westnet.com.au...

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:b5m5qpF8brtU1@mid.individual.net...

"gcd"

I'm trying to identify a Motorola surface mount diode.

The code on the didoe is 607 with a datecode of 9318. It's a Motorola
from the logo. I've not had success with google trying to find it,
would anyone have any ides? I think it's azener, or perhaps a
schottky.


** Why not test it - if it still functioning.



... Phil


Hi,
I'm reasonably sure it's damaged.

I didn't reverse engineer enough of the circuit and found this diode
directly across a filter cap after a 2 diode rectifier in a smps after
it heated enough to melt the solder on the board. (wound the external
supply up to 15V with 100-150mA current limit set).

So the diode now measures around 0.7V forward and breaks down at around
17-18v.

Sounds like maybe a zener, while regular diodes can drop as much as 1.1V
at max rated current, 0.7V is regarded as "nominal". In actual fact; a
DMM diode check is likely to show nearer 0.65V (even lower for fast
diodes) - the diode check will actually show 0.7V on a zener.

Shottky-barrier diodes vary considerably depending on current rating,
I've measured as low as 0.1V for big stud mounted rectifiers, and (I
think) about 0.4V for the likes of a 1N5817 etc.

The low reverse breakdown adds credibility to the idea of it being a
zener.
Hi,
the 15V breakdown also made me consider the schottky, that's a typical
schottky breakdown voltage.
But a zener sounds more logical than a schottky. However such a brute
force approach is likley to cause collateral daamge within the smps than
something more elegant.

Hopefully your SMPS has an overcurrent trip.

BTW: you're unlikey to find many SB diodes less than 20V, except in VHF/UHF
small signal applications.

They do however get used as sacrificial crowbars - I've found them
occasionally protecting the G-S of the SMPS MOSFET in PC monitors - more
often than not regulation failure caused core saturation and blew the
internal structure of the MOSFET and/or the source current sense resistor,
if the clamp diode protected anything at all - it was usually the SMPSU
chip.