Inexpensive ESD (static) protection.

Hi LazyBeam,

Great post with great insights!!

LazyBeam said:

I think the LASORB is OK and works but the laser hobbyist market might not be the best place for it.

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Hehe. So it seems ;-)

LazyBeam said:

#1) An $8 device is a significant price compared to most enthusist diodes.

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Yes, I did not know that up until now. Somehow I related LPF guys to PL guys because both use laser diodes. PL guys routinely use LASORB and swear by it. Your insight here seems right on the money (no pun intended)...

LazyBeam said:

#2) Most hobbyists working with expensive diodes have good ESD practices and are unlikely to subject thier diode to unecessary ESD.

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LazyBeam said:

In reality, the average hobbyist doesn't need the gold standard of protection. A cap/zener/TVS device that offers some protection is usually good enough. This may not be true for a business or comemrcial product.

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Actually we can demonstrate that TVS, Caps, Resistors, etc. do almost nothing for laser diode protection. So if people are not having problems, then it's because of good handling practices and luck.

LazyBeam said:

#3) Most laser enthusists tolerate any failures with only minor inconvenience.

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Yes, it seems so for people here. If you're only talking about a very low power red laser diode, then sure, the diode getting blown is just a minor inconvenience. But somehow I figured there would be some folks on here with more expensive 445 or BLU-RAY diodes where a failure would be more than just a minor inconvenience...

I guess I was wrong in my assumptions ;-)

Best regards,

William Benner

It is possible that the transient events we are experiencing in our typical application are not nanosecond events, therefore the discussed alternatives have merit.

jib77 said:

It is possible that the transient events we are experiencing in our typical application are not nanosecond events, therefore the discussed alternatives have merit.

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Hehe. Well, it is a good guess in a vacuum, but actually the "discussed alternatives" don't have merit...

Yes, ESD contains a big pulse with rise time around 0.7nS, but then there is a follow-on wave that takes tens of nanoseconds to dissipate. In fact this is where all of the real energy is.

The problem for laser diodes isn't exclusively due to the fast nature of ESD, but also that it results in voltages higher than the nominal terminal voltage of a laser diode. If the nominal terminal voltage is exceeded -- even for just a short time, the laser diode will be damaged - especially low power red diodes that have aluminum in the active region. This is why clamping techniques simply won't work.

LASORB has fast reaction time, but once it is triggered, it can actually remain conductive (thus protecting a laser diode) for lengths of times in the milliseconds. That's why we say "ESD and power surges" and not just "ESD". Often times it is power surges that take place when you are turning a laser system on or off (not just modulating, but really applying AC power to the whole system) when damage will be done.

All of the information is on the LASORB web site. Not only information about the final LASORB device, but an explanation of all of the other techniques and why they won't work, and the physics behind it all. It's all there if someone cares to read about it...

Best regards,

William Benner

Well, i've glanced over the website, especially the part debunking other protective measures. The 'simple capacitor' one is interesting. The site states that a 1 uF capacitor would be albe to mitigate the discharge, but it doesnt work because of parasitic inductances. This may very well be true for some real world capacitors. But what if we added a small ceramic capacitor too? And/or a resistor in the leads to mitigate the slow capacitor response?

The protection against surges from misbehaving drivers could however be interesting. Not that they are superior to other techniques, but to realize that in a single component could be attractive in systems that need to be fail-proof.

I do think that the price will have to come way down for this component to see mainstream application though. If we see real availability of the device for $2 or less in single unit quantities, i think there will be a much larger market.

Benm said:

The site states that a 1 uF capacitor would be albe to mitigate the discharge, but it doesnt work because of parasitic inductances. This may very well be true for some real world capacitors. But what if we added a small ceramic capacitor too? And/or a resistor in the leads to mitigate the slow capacitor response?

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1uF is the number, according to the math. To approach it in real life, you basically have to make a perfect 1uF capacitor. One colleague created one with a bunch of smaller SMT capacitors, stacked and soldered vertically in cascading and ascending values. They believe it worked, but it was a tall basically "3D" structure. And then try to modulate against 1uF... Bandwidth decreases dramatically.

Benm said:

The protection against surges from misbehaving drivers could however be interesting.

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Yes, exactly. Really that's what we started developing first, a driver for a mission-critical aerospace application. We first examined other drivers on the market (because we simply wanted them to use our software and get the driver somewhere else). What we discovered was that no existing driver could meet the specs that this aerospace company needed, and many were really poorly designed.

Some companies that use LASORB use it as a band-aid to solve the problems that are really caused by their driver design.

Benm said:

I do think that the price will have to come way down for this component to see mainstream application though.

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Hehe. According to purchase volumes, it's already mainstream ;-)

Benm said:

If we see real availability of the device for $2 or less in single unit quantities, i think there will be a much larger market.

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Well, "larger" is a qualitative term not a quantitative term. I am not sure how many LPF members there are, but if every single person on LPF were to buy this, then yes, our market would be "larger". But I would venture a bet that such a volume is dwarfed by the volume of our single largest consumer.

Best regards,

William Benner

There are numerous pricing schemes feasible though. You could, for example, sell units with a warantee at a premium, and the exact same units without warantee at a much lower price.

The only difference would be that you would be willing to compensate the costs of a failing unit in one scenario, but not in the other.

Especially in space application a warantee would be very useful since the cost of a re-launch is excessive. The value of a protection measure in space could be a million dollars, while the same protection is wordt only a penny on the surface.

Its a bit like insurance: not important if the only loss you stand to suffer is a few tenners for replacing a diode, feasible if a failure would ruin your party, and obligatory if a failure would result in a multi-million dollar re-launch of a sat.

Pangolin said:

Hehe. Well, you guys raise a number of interesting points and questions, and there are some basic answers I can give:

Even if a laser diode is only $15, the question is, what is the cost of an overall system failure?

Some of our clients use low-cost laser diodes in machines that themselves cost tens of thousands of dollars! Others use them in medical devices. Still others use them on the Mars Explorer. The diode itself may be inexpensive, but an overall system failure could be literally fatal!

Up until now, I believed this forum was vaguely similar to Photon Lexicon, since everyone uses laser diodes. I guess the guys on Photon Lexicon are using higher-power diodes, and so the cost of protection seems more reasonable... Many folks on Photon Lexicon are using our LASORB to protect their laser diodes and find significant value in it.

In any event, for hobbyists on this forum, it might not be all that important. If you folks don't see the value, then you don't see the value, and that's that. But for people who want to protect laser diodes that are significantly more expensive, or who absolutely can not tolerate a failure, LASORB is an absolute bargain!

Best regards,

William Benner

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Here's the deal. The Lasorb has a very narrow market window.
It's only useful for people throwing together their own designs, people opening up other designs and sticking their fingers into them, or people who build a system and decide to NOT enclose and shield their electronics.
If Lasorbs were cheap, hobbyists would use them all over - because they are some of the only people who need them.

OEM's, and others who have good designs and static-safe build environments ship millions of laser-diode based devices: all without Lasorbs.

Really, you might want to re-price to increase your market penetration into the low-end, where they are needed most.

Markus

Abusive treatment of our community should also be moderated, hint hint

@jib77: yes, these are "avalanche zeners" (Same as zener diodes, but more fast ones) ..... used as industrial level, and good enough too, especially if you need to modulate the LD at discretely high frequency, cause the internal capacity is less than 40pF.



@Benm: "simple capacitor" system don't protect you from continuous overvoltages (not "spikes", i mean), anyway, and also, ESR of some capacitor is too high ..... "simple resistor" is better, in this sense (there's no active devices that can work more fast than an 1Kohm 2mm SMD resistor, after all ..... and at 1Kohm, it does not draw any significant current from the LD, and at the same time, protects you from any ESD), and for better safety, you can add a 10nF (or 100nF, if you don't need to modulate the LD fast) in parallel to the resistor, for take care about the quick pulses ..... and, for "labby" setups, a 6,8V zener, or also a fast diode like the common 1N4148 added to the assembly, make a total protection also against reversal of power supply (well, ok, it can be done also directly on the LD, but not all the hobbysts want to do soldering works like mine )



@Pangolin: what about the last point of my previous post ?

Sry to dig this thread up. but im wanting to know a good cheap way to build esd protection.
So let me ask.
Digi-Key - 568-4044-1-ND (Manufacturer - PESD3V3S1UB,115)
That plus a 1k 805smd resistor
plus a 0.01uF
Would be the best way to keep my diodes alive?
All that is about 1$ for good esd protection.
Im building lab setups and portables so i would love to have great esd protection.
And im not paying 8$ for a lasorb, i just cant.

Hi kiyoukan,

If you want to protect your laser diodes from ESD or spike-related failures, the best way is to use a product specifically designed to protect laser diodes -- namely LASORB from Pangolin (LASORB - ESD absorber for laser diodes)

We make this statement not only because we manufacture the product, and not only because we've tested all other methods, but because it can be proven to be true and is now overwhelmingly recognized by laser manufacturers and trade journals.

The part you pointed to can not protect a laser diode -- if for no other reason, one of threshold voltage which, for a laser diode, changes with time and temperature. And resistors and capacitors will not help ESD, and may make the driver circuit less stable.

You might check out the section of the LASORB web site on which we review other techniques.

Of course, you can do anything you want, and you purchasing or not purchasing LASORB will not make Pangolin any richer or any poorer. So to me, it's not a matter of money. It's a matter of offering good solid protection.

Best regards,

William Benner

Hey William....

after the many...many thousands of Lasorbs that you have no
doubt sold all over the globe why not entice some of the LPF
members by offering a reasonable discount on your Lasorbs...

I'm sure some of the members using some of the more expensive
LDs may choose to use them...

It may also help if you could come up with a smaller package.


Jerry

the problem with lasorb is its to big.
i make and sell drivers and i am building a driver with lots of esd protection.
So maybe if you can offer a way to build what you have on a smaller scale i would buy.
But the size and form factor are to large to make portable.
So with my post above will those 3 things help or no?
or not to much?
Another note i dont see lasorbs in casio projectors....
There must be another way.

@Jerry,

We believe that the prices we charge are fair, and based on quantity scheme. I don't know your background, but if you study the inner workings of a company (a subject on which I'm involved in writing two separate business books -- see Facebook for the most up to date information), then you no doubt understand that companies have "overhead". If we charged $2 for a single-piece purchase of LASORB, I am sure we would lose money on overhead expenses. So for single-piece purchases, the cost of $8 is still far less than a laser diode, and if it prevents a catastrophe later on, then the cost seems tiny. If you want to buy many LASORB, then the price gets down to $2 each.

@Kiyoukan, some laser diodes are more resistant to ESD than others. We are very clear that low power laser diodes are the most vulnerable and high power C-mount diodes are almost impervious to ESD. The diodes used in Casio are resistant to ESD, but not completely resistant. In our testing at Pangolin we were able to blow them, and able to prove that they could be protected by LASORB. As a final point, just because you don't *think* that you see LASORB, doesn't mean it's not actually there! This is because -- regarding package size, we try to encourage communication and direct dialog. We are in a position where we can (and do with many companies who have large volume requirements) offer a much more compact solution. So let's get into a dialog about this, through private email, at Contact Us

Best regards,

William Benner

something tells me the custom lasorb is going to make the price of my driver 2x more than its worth now.
my drivers sell for about 7.50$ and i can make money off them if i have to add a 8$ part thats worth more than the driver its kind worthless.
I can build almost anything electronic very close to free and with zero part cost.
So if we can discuses maybe just circuits on how to build a lasorb like device that would be help full.

Well, certainly when we do what you called the "custom solution" it winds up to be less expensive for customers than our current packaged product.

And hehe, as far as "2x more than it's worth", I would say that "worth" is in the eye of the beholder... If you are selling something for $7.50 and Coherent is selling something for $7,500, then clearly the "worth" is a matter of presentation and marketing (and of course technical capability).

In any event, if life experience on earth teaches us anything, it is that you get what you pay for...

Best regards,

William Benner