I didn’t think to ask because on a local forum people advise against digikey due to that. They do ship with VAT paid when you’re business (have a VAT number).
For a long time I avoided Digikey for that reason, my first order in 2014 was indeed a hassle. But since then Digikey.se was introduced and last year I wanted some stuff that only Digikey had so I decided to give it a go and was pleasantly surprised. Now I don’t care weather it’s Digikey or Mouser, I order where the parts are which is very convenient.
Nice project! Anti flicker in moon level is the first problem solved in your driver? 
I think I ordered more 61288s than I need. If you want, send me a PM once your driver boards arrive from OSH Park and I can send you one or two. You can paypal me the cost once you receive it, no need for pre-payment.
Thanks you for the offer, I may still make an order from them as they have other a few other thing I’d like, but If I don’t I’ll PM you. 
Some news!
I received the last parts Wednesday (at last), yesterday I made one board, first time reflowing anything else than an LED but it turned out well :
This morning I tested the driver, only the hardware by bypassing the MCU :
And it works! The output voltage/current is stable, here is a quick output voltage waveform with the scope I just bought :
The only issue is that I got less current than expected, with 44mV ref voltage and 9.2mΩ (7+mosfet resistance) I should get ~4.78A, but I only get ~3.7A. After a quick check the real ref is ~43mV and the mosfet resistance is ~4.4mΩ which explains the difference. Swapping the resistance with a 5mΩ one should do the trick, but I’m worried about the ON resistance variation of the mosfet between parts.
Next I need to adapt Anduril for it.
I just received 21mm boards from Oshpark
They’re prettier.
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I’m not sure how I’ve missed this thread! Well done, thefreeman! I can’t wait to see this develop more. And of course, I’m happy to see the usage of the 1-Series AVRs.
Congratulations! I cant wait to see how this turns out…
How does your driver regarding these characteristics? If behaves well regarding these qualities (from dtr’s laser shop), your driver could be a good choice for LEP driver swaps if more e-switch LEPs pop up in the future.
An ideal power supply for a laser diode has the following characteristics:
• Current source
• Transient suppression (also low noise)
• Independent clamping current limit
• Slow start / ramping the current signal during switch-on
• Output overvoltage protection
• Input undervoltage detection
• Output short-circuit / interruption detection
• Shorting output during driver off status for ESD protection
• No undershooting of the output voltage at switch-off of the laser, so that a negative voltage over the laser diode cannot occur.
Thanks.
I got a bit of a scare yesterday, I couldn’t read the device in microchip studio. Couldn’t sleep while trying to figure out what was wrong, then it clicked, I ordered the older programing key :person_facepalming: , despite that you told me you changed it, I completely forgot that, I must have had the older key already in my oshpark projects. Thankfully it didn’t fry the chip (5V on UDPI, UDPI on GND, GND on +).
For now I just tested your TCD sample code.
Aren’t laser diodes low voltage ? The present driver uses a boost converter for voltages higher than li-ion.
• Current source : yes.
• Transient suppression (also low noise) : switching converters are noisy, maybe a linear driver would be better suited for this.
• Independent clamping current limit : sometimes there is an adjustable switch limit but this isn’t the case with the TPS61288 (fixed limit).
• Slow start / ramping the current signal during switch-on : sure that’s possible, in hardware (it’s already the case, but can be increased) or software.
• Output overvoltage protection : yes.
• Input undervoltage detection : most switching ICs have an undervoltage lockout, sometimes adjustable, on the TPS61288 it’s 1.9V, can be done in software, anduril have a default LVP of 2.8V (or 2.7 ?).
• Output short-circuit / interruption detection : don’t know how to do that.
• Shorting output during driver off status for ESD protection : idem.
• No undershooting of the output voltage at switch-off of the laser, so that a negative voltage over the laser diode cannot occur. : not sure about this either.
I made a quick efficiency measurement, this is with a current clamp so it’s not very precise.
Vin : 3.96V Iin 6.36A Pin = 25.19W
Vout : 6.40V Iout : 3.73A Pout = 23.87W
Efficiency = 94.8%
This is with a reverse protection PFET, without it it could increase by 0.5~1, and with a bigger inductor with lower DCR like a XAL7070 maybe ~1 (more at lower input voltage)
Good.
Probably a long way off but if you end up making these in any quantity I will need to purchase at least one. It seems a 12v e-switch boost driver is kind of a unicorn, I need one for an FT02 host with the GT-FC40 LED, to have one with Anduril would be even better.
I will probably make some, what is the size and available height ?
I think it is 25mm in diameter, might be 26mm, I can check when I have it in hand. In terms of height, I can check that also but I don’t think component height will be major limiting factor, it does use a boost driver stock and the battery tube has a lot of extra space too. Thank you for responding, and for your work on this project, very exciting.
I would need a few for KR1 and M21C-U... just saying...
KR1 has a tail switch with signal tube (as you probably noticed ), it would require a different PCB. Bigger PCBs are easy though, just need to increase the diameter.