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John Larkin
Guest
Thu Mar 11, 2010 1:01 am
On Wed, 10 Mar 2010 17:43:28 -0600, "Jon Slaughter"
<Jon_Slaughter_at_Hotmail.com> wrote:
Quote:
Jon Slaughter wrote:
What does a diode laser module add to a diode laser? A voltage
regulator or current limiter?
How do I determine the working current from the datasheet? I have an OPV322
that I ran from about 3mA to 5mA. The datasheet says the max is 12mA(Maximum
Forward Peak Continuous Current) and the threshold is 3mA. It says the min
total power output is 1.5mW at If=7mA.
So I take it that the operating range is 3mA to 12mA with average of 7mA?
What I don't understand is that mouser listed this as a 5mW part and on the
datasheet it has the warning box which says 10mW and the spec says 1.5mW.
In any case it does work but I would like to get about 80-90% of the maximum
which I'm figuring is about 10mA.
Lousy data sheet!
I've had weird experiences with Optek lasers. And their applications
engineers don't seem to know much about their own parts. I think they
buy chips in rainy back alleys in Singapore or something.
And they keep changing the recipes. Different batches seem to be
different parts.
What are you doing with them?
John
JosephKK
Guest
Thu Mar 11, 2010 1:54 am
On Tue, 9 Mar 2010 13:36:34 -0600, "Jon Slaughter" <Jon_Slaughter_at_Hotmail.com> wrote:
Quote:
What does a diode laser module add to a diode laser? A voltage regulator or
current limiter?
Most often, an optical interface with a connector.
Guest
Thu Mar 11, 2010 3:32 am
Quote:
What I don't understand is that mouser listed this as a 5mW part and on the
datasheet it has the warning box which says 10mW and the spec says 1.5mW.
In any case it does work but I would like to get about 80-90% of the maximum
which I'm figuring is about 10mA.
Dang sticker power is always at least twice the rated power, it is the
theoretical max power before the part would incinerate itself and
allows for a wide safety margin.
Steve
Jon Slaughter
Guest
Thu Mar 11, 2010 3:48 am
John Larkin wrote:
Quote:
On Wed, 10 Mar 2010 17:43:28 -0600, "Jon Slaughter"
Jon_Slaughter_at_Hotmail.com> wrote:
Jon Slaughter wrote:
What does a diode laser module add to a diode laser? A voltage
regulator or current limiter?
How do I determine the working current from the datasheet? I have an
OPV322 that I ran from about 3mA to 5mA. The datasheet says the max
is 12mA(Maximum Forward Peak Continuous Current) and the threshold
is 3mA. It says the min total power output is 1.5mW at If=7mA.
So I take it that the operating range is 3mA to 12mA with average of
7mA?
What I don't understand is that mouser listed this as a 5mW part and
on the datasheet it has the warning box which says 10mW and the spec
says 1.5mW.
In any case it does work but I would like to get about 80-90% of the
maximum which I'm figuring is about 10mA.
Lousy data sheet!
I've had weird experiences with Optek lasers. And their applications
engineers don't seem to know much about their own parts. I think they
buy chips in rainy back alleys in Singapore or something.
And they keep changing the recipes. Different batches seem to be
different parts.
What are you doing with them?
Just playing around with some night vision stuff. I got it to 10mA and it
didn't burn up so I figure that is probably the max I'll take it. It's
nothing serious. Main thing I need to deal with is the optics. Essentially
trying to build an infrared flashlight to replace one that used an IR led
and was terrible. Nothing serious though and just for fun. Main thing I
gotta worry about is not doing self-lasik ;)
Basically 6V's got me 1.7V across the diode at 10mA(had 430Ohms in series).
Thats 17mW which far exceeds the spec if they are 5mW's unless I'm missing
something.
John Devereux
Guest
Thu Mar 11, 2010 7:59 am
"Jon Slaughter" <Jon_Slaughter_at_Hotmail.com> writes:
Quote:
John Larkin wrote:
On Wed, 10 Mar 2010 17:43:28 -0600, "Jon Slaughter"
Jon_Slaughter_at_Hotmail.com> wrote:
Jon Slaughter wrote:
What does a diode laser module add to a diode laser? A voltage
regulator or current limiter?
How do I determine the working current from the datasheet? I have an
OPV322 that I ran from about 3mA to 5mA. The datasheet says the max
is 12mA(Maximum Forward Peak Continuous Current) and the threshold
is 3mA. It says the min total power output is 1.5mW at If=7mA.
So I take it that the operating range is 3mA to 12mA with average of
7mA?
What I don't understand is that mouser listed this as a 5mW part and
on the datasheet it has the warning box which says 10mW and the spec
says 1.5mW.
In any case it does work but I would like to get about 80-90% of the
maximum which I'm figuring is about 10mA.
Lousy data sheet!
I've had weird experiences with Optek lasers. And their applications
engineers don't seem to know much about their own parts. I think they
buy chips in rainy back alleys in Singapore or something.
And they keep changing the recipes. Different batches seem to be
different parts.
What are you doing with them?
Just playing around with some night vision stuff. I got it to 10mA and
it didn't burn up so I figure that is probably the max I'll take
it. It's nothing serious. Main thing I need to deal with is the
optics. Essentially trying to build an infrared flashlight to replace
one that used an IR led and was terrible. Nothing serious though and
just for fun. Main thing I gotta worry about is not doing self-lasik
;)
Basically 6V's got me 1.7V across the diode at 10mA(had 430Ohms in
series). Thats 17mW which far exceeds the spec if they are 5mW's
unless I'm missing something.
You are missing that the spec is for the *optical power output*, but you
are measuring the power input!
The failure mechanism for laser diodes is usually excessive optical
output power, so it is this that you must constrain,
But your 10mA is just about within the 12mA @25'C rating, so that is why
it has not blown up.
Careful - laser diodes are normally very sensitive to even very short
overloads (microseconds-nanoseconds). You may already have blown it
up. It would still take current but the output will be down to almost
nothing (it turns into a weak LED). You need to be careful with ESD.
Having said that this one accepts a 48mA 1us pulse so it is not as
sensitive as some.
--
John Devereux
Joerg
Guest
Thu Mar 11, 2010 4:52 pm
John Devereux wrote:
Quote:
"Jon Slaughter" <Jon_Slaughter_at_Hotmail.com> writes:
John Larkin wrote:
On Wed, 10 Mar 2010 17:43:28 -0600, "Jon Slaughter"
Jon_Slaughter_at_Hotmail.com> wrote:
Jon Slaughter wrote:
What does a diode laser module add to a diode laser? A voltage
regulator or current limiter?
How do I determine the working current from the datasheet? I have an
OPV322 that I ran from about 3mA to 5mA. The datasheet says the max
is 12mA(Maximum Forward Peak Continuous Current) and the threshold
is 3mA. It says the min total power output is 1.5mW at If=7mA.
So I take it that the operating range is 3mA to 12mA with average of
7mA?
What I don't understand is that mouser listed this as a 5mW part and
on the datasheet it has the warning box which says 10mW and the spec
says 1.5mW.
In any case it does work but I would like to get about 80-90% of the
maximum which I'm figuring is about 10mA.
Lousy data sheet!
I've had weird experiences with Optek lasers. And their applications
engineers don't seem to know much about their own parts. I think they
buy chips in rainy back alleys in Singapore or something.
And they keep changing the recipes. Different batches seem to be
different parts.
What are you doing with them?
Just playing around with some night vision stuff. I got it to 10mA and
it didn't burn up so I figure that is probably the max I'll take
it. It's nothing serious. Main thing I need to deal with is the
optics. Essentially trying to build an infrared flashlight to replace
one that used an IR led and was terrible. Nothing serious though and
just for fun. Main thing I gotta worry about is not doing self-lasik
;)
Basically 6V's got me 1.7V across the diode at 10mA(had 430Ohms in
series). Thats 17mW which far exceeds the spec if they are 5mW's
unless I'm missing something.
You are missing that the spec is for the *optical power output*, but you
are measuring the power input!
The failure mechanism for laser diodes is usually excessive optical
output power, so it is this that you must constrain,
But your 10mA is just about within the 12mA @25'C rating, so that is why
it has not blown up.
Careful - laser diodes are normally very sensitive to even very short
overloads (microseconds-nanoseconds). You may already have blown it
up. It would still take current but the output will be down to almost
nothing (it turns into a weak LED). You need to be careful with ESD.
Having said that this one accepts a 48mA 1us pulse so it is not as
sensitive as some.
They can also be killed if they are run borderline and then some
reflection changes in the optical path, meaning outside the part. Except
that you won't hear a PHUT sound, it just quietly signs off for good.
--
Regards, Joerg
http://www.analogconsultants.com/
"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
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