Except you want the D2PAK version not the SOT223.
LT3080EQ#PBF - LINEAR TECHNOLOGY - LDO, REG, 0V TO 36V, 1.1A, 5D2PAK | Farnell United Kingdom
~Tom
LT3080EQ#PBF - LINEAR TECHNOLOGY - LDO, REG, 0V TO 36V, 1.1A, 5D2PAK | Farnell United Kingdom
~Tom
Would anyone be willing to share their specification for a heatsink for Tom's regulator? Type of stock, size, location of mounting hole, hole thread size, etc? (If you're not using Heatsink USA, let us know who you are using.)
This might include thoughts of how or if to mount the PCB to the heatsink, as well as how to securely mount the entire assembly to something else.
I know I'd benefit from someone who's been there and done this, and maybe we could get some benefit from standardization.
This might include thoughts of how or if to mount the PCB to the heatsink, as well as how to securely mount the entire assembly to something else.
I know I'd benefit from someone who's been there and done this, and maybe we could get some benefit from standardization.
In my 300B amp, I actually used an old heat sink from Assmann. The profile is V 5434. At 75 mm length, its thermal resistance is about 1 K/W. I fished two of these out of a tub skid at a junkyard in the outskirts of Copenhagen when I lived there. I bought them for the raw aluminum cost.
Assmann is represented in the US, though, none of their distis seem to carry heat sinks.
I've used Wakefield in the past as well.
~Tom
Assmann is represented in the US, though, none of their distis seem to carry heat sinks.
I've used Wakefield in the past as well.
~Tom
Definitely mount the PCB. In my amp, I bent the leads on the mosfet 90 degrees and had the PCB parallel to the heat sink. I drilled and tapped M3x0.5 mm holes for the board and the MOS device. Use a thermal washer between the MOS device an the heat sink.
You never want the board just dangling off the FET leads. That's a recipe for disaster (and metal fatigue).
~Tom
You never want the board just dangling off the FET leads. That's a recipe for disaster (and metal fatigue).
~Tom
Yeah... I thought of that a while back, but the thought evaporated shortly after that. Thanks for bringing it up again.
~Tom
I just worked through this this past weekend...
Here's the dimensions you need
http://www.st.com/web/en/resource/technical/document/datasheet/CD00080694.pdf
The Christiansen "DG" 300B Amplifier Build Thread - see post#1
I am now looking for a stand-off with a 90 degree hole to mount the PC board to the heatsink
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Two options:
1) Drill and tap blind holes into the heat sink. Bend the leads on the MOSFET 90 degrees and mount it to the heat sink. Mount the board parallel to the heat sink.
2) Make a bracket (or buy one ready made from Digikey and the like places) and mount the board perpendicular to the heat sink.
Options, options. Personally, I prefer option 1) as it makes for a nice voltage regulator module.
~Tom
Good afternoon all,
Digi-key has the following message regarding STW12NK95Z availability:
"Part will become a non-stocking item when stock is depleted; minimums will apply.
Order the quantity available or the quantity available plus a multiple of the minimum order quantity."
Reading through the thread, it seems that it took Tom a lot of research before he settled on this MOSFET. Any thoughts on a suitable replacement? At first blush, the STW13NK100Z seems like a good candidate, but I have not looked at it in detail.
thanks much,
ben
http://www.digikey.com/product-detail/en/STW13NK100Z/497-3556-5-ND/669409
Digi-key has the following message regarding STW12NK95Z availability:
"Part will become a non-stocking item when stock is depleted; minimums will apply.
Order the quantity available or the quantity available plus a multiple of the minimum order quantity."
Reading through the thread, it seems that it took Tom a lot of research before he settled on this MOSFET. Any thoughts on a suitable replacement? At first blush, the STW13NK100Z seems like a good candidate, but I have not looked at it in detail.
thanks much,
ben
http://www.digikey.com/product-detail/en/STW13NK100Z/497-3556-5-ND/669409
Most MOS devices capable of handling more than 200 W and Vds greater than the worst case input voltage should work. I'd keep an eye on the capacitances of the device and ensure that it's comparable to the STW12NK95Z - just to be safe...
Most of my challenges were related to finding a device that could handle the in-rush current and it was rather eye-opening for me to need a 230 W capable device in a 5 W application.
One of these days, I'll sit down and look at some devices to come up with a list of suitable candidates. It would be nice to include some devices more commonly available in Europe on that list. I hear the IXYS devices are hard to get over there.
~Tom
Most of my challenges were related to finding a device that could handle the in-rush current and it was rather eye-opening for me to need a 230 W capable device in a 5 W application.
One of these days, I'll sit down and look at some devices to come up with a list of suitable candidates. It would be nice to include some devices more commonly available in Europe on that list. I hear the IXYS devices are hard to get over there.
~Tom
Hi Tom,
Thanks for the reply. I started putting together a little chart last night of what I think might be good substitutes - listing parameters of the original and possible replacements. There seems to be plenty to chose from, unless I'm missing something subtle in the datasheets.
It then struck me that if I could easily do it, I'd like to include what is available in Europe.
What are the European equivalents to Digi-Key and Mouser? Farnell and RS, maybe?
thanks,
ben
Thanks for the reply. I started putting together a little chart last night of what I think might be good substitutes - listing parameters of the original and possible replacements. There seems to be plenty to chose from, unless I'm missing something subtle in the datasheets.
It then struck me that if I could easily do it, I'd like to include what is available in Europe. What are the European equivalents to Digi-Key and Mouser? Farnell and RS, maybe?
thanks,
ben
Farnell and RS are the big distis. When I was living over there, there were a bunch of smaller, local stores as well.
I used to shop at Vejle RC Elektronik in Denmark. Judging by their selection today, it looks like low-voltage International Rectifier parts are abundant with a few high-voltage parts sprinkled in for fun.
~Tom
I used to shop at Vejle RC Elektronik in Denmark. Judging by their selection today, it looks like low-voltage International Rectifier parts are abundant with a few high-voltage parts sprinkled in for fun.
~Tom
Quick question - looking to apply your regulator to an existing 520 VDC supply to yield a 500 VDC output at 150mA load. (The 520 VDC above is at 150mA load, about 560 VDC at no load)
Any idea what drop-out voltage in your circuit might be? To me, it seems like it should be very small. For my application that's passing 150mA, there is less than 0.1 volt in R3, the LT3080 datasheet shows less than 350 mV (let's round up to 500 mV), and the MOSFET should be less than 500 mV easily, as long as it is fully turned on. So less than a volt. What am I missing?
The only thing I'm unsure about above is if the MOSFET is fully turned on. I'm trying to get my mind around how the LT3080 interacts with the gate and source to develop a gate to source differential to turn the MOSFET on.
Please note, I'm not an electrical engineer...just a simply hobbyist so please be gentle.
thanks much,
ben
Any idea what drop-out voltage in your circuit might be? To me, it seems like it should be very small. For my application that's passing 150mA, there is less than 0.1 volt in R3, the LT3080 datasheet shows less than 350 mV (let's round up to 500 mV), and the MOSFET should be less than 500 mV easily, as long as it is fully turned on. So less than a volt. What am I missing?
The only thing I'm unsure about above is if the MOSFET is fully turned on. I'm trying to get my mind around how the LT3080 interacts with the gate and source to develop a gate to source differential to turn the MOSFET on.
Please note, I'm not an electrical engineer...just a simply hobbyist so please be gentle.
thanks much,
ben
Please ignore my question above - found the drop-out to be 15 volts in the second message in this thread, with 25 volts recommended. Of course, I only found that AFTER asking my question...
But I'm still curious as to how I'm wrong in estimating the drop-out voltage - has to be in the MOSFET...
thanks much,
ben
But I'm still curious as to how I'm wrong in estimating the drop-out voltage - has to be in the MOSFET...
thanks much,
ben