looks good....but.
Make sure to put a ceramic cap (10n say) at the LD pin. (...oh you already have, nice work)
Also, make sure you put a cap right at the vin pin....eg a ceramic of a couple of microfarads.
Also, your input caps are 35v rated, that is not enough.
Remember a ceramic cap should have a voltage rating at least 20-30% more
than the rail it sits across.
Put a 27k (apprx) signal , eg 0603 resistor or 0805 at the fet gate, from gate to ground.
Have a zero ohm resistor in between GATE pin and gate of fet...that's just in case you need to damp the switching transistion....have an actual zero ohms resistor,
and if you need to damp, because of noisiness, then make it a 4r7 say.
ensure c3 is near the pin.
Put a cap (ceramic) of 100n, 50V min, across LED- and LED+, but make it near the Power diode and not near the leds.....then take the wires to the leds off as a twisted pair....actually no, make this cap at least 63v rated...because in the event of someone accidentally yanking the load connector out whilst the led driver is powering the load at full power, then there will be an overvoltage ringing on this capacitor, so make it 63V rated.
Make the pot a multi turn pot if possible.
When you power it up, first have the pot to give 0v at LD pin, then wind it up to your max power.....which I think we calculated was 0.2V?... see calcs previously.
Remember the inductor is 100uH....ok you can use 220uh and the 124k off time resistor if you want.......it does bring the switching freq near the audible range, but is maybe better for noise reasons etc so go for it if you want.....220uh and you may get too much winding loss though and core loss...depending)
Yes you absolutely must use the "HV9910B" from supertex (though I think supertex is microchip now?)
Don't use the Clare one , or any other, it must be the HV9910B only.
the other ones aren't constant off time.
Did you follow the power ratings for the sense resistor?
Check the part number for the input caps to make sure enough ripple rating, though we know that some of the ac will be drawn from the batt....ensure the input wires for power, if possible are twisted or at least run side by side.
Use a bigger shcottky, bigger fet.
Presumably you are going to wind the inductor yourself, using which core set? (must be ferrite)
regarding THE INDUCTOR....
https://www.epcos.com/epcos-en/5294...ites-and-accessories/pq-cores-and-accessories
You could use 13 turns on the PQ50/50 core of the above link.......but it needs an "overall" air gap of 0.5mm...the gap must be in the centre leg only.....so you shave off 0.25mm of each of the core half centre leg surfaces....to give the overall 0.5mm air gap. Otherwise if you don't use the gap it will saturate...I doubt you will be able to put the gap in yourself...it is very difficult as ferrite is rock hard and brittle...a transformer winders would need to do it for you.
So that's 13 turns (FOR 100Uh) of enamelled copper wire round the gapped PQ50/50 core.
The PQ5050 CORE with 0.5mm gap gives you up to 10.9A with the 100uH...this gives you nice safetymargin........if you want smaller inductor give me a shout and ill do it again with the samller members of the PQ core family.....
The inductor (gapped) calc sheet is as attached..
Use minimum 1mm diameter enamelled copper wire.
If you cant afford to send the core halves off for gapping, then I suppose then you have to just put spacers in between the core halves to give an overall 0.5mm gap.
Remember with such spacers, its the total gap you have to get to 0.5mm, not every individual gap.
If you want you could just get an inductance meter and do it imperically....keep gapping it and measuring the inductance...but beware, if you gap less than 0.2mm then you could saturate when at max current when in the lamp.
The alternative is just to send the core off to a winder and ask for inductance of 100uh and rms current 7amps (say). Say it should not saturate up to 7.5 amps.
You don't need to use litz wire as your frequency is so low.