Just made a quick BOM on Digikey without resistors (I have to read everything before) and LSK. Could you check it?
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Any source for Linear in Europe or I should buy LSK389 from NAC?
LSK389A-SOIC | LINEAR SYSTEMS | NAC Semi
Please Help me 😀
LSK389A-SOIC | LINEAR SYSTEMS | NAC Semi
Please Help me 😀
Thanks, I'm trying with Italian distributor...
Here's my Digi-Key BOM for the rest of the parts
Ok, I'll change it. The others seems ok... Do you suggest a particular brand/type of resistors?
With respect to choice of the passives -- I am using Rohm -- but I don't think that there is going to be a critical effect to use -- in my box of SMT 0805's I have Panasonic, Vishay and Yageo.
I would suggest building the output stage first! Both the SMT and Through-Hole MOSFETs are very static sensitive.
I would suggest building the output stage first! Both the SMT and Through-Hole MOSFETs are very static sensitive.
Thanks for reply. So, I have to start with all semiconductors and after add all res and caps. What power of res did you use for the whole project?
For other Italian builders: Schurter (distributor for IT) supplies Linear products only for big quantities. They addressed me to digi-key but I obtain the reference only in .com site:
Digi-key
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> with the 2SK209 the gain will probably be about 3dB lower
Just use 2x 2SK209GR in parallel. Or 1x 2SK2145GR dual, wired in parallel.
Very close to 1x 2SK170BL, in every aspect.
NJFETs for Source Follower Applications
> On matching SOT devices
https://www.newark.com/peak/pca23/test-adapter-sot-23/dp/50AC8675
One time investment, or share cost in a group match action.
Patrick
Just use 2x 2SK209GR in parallel. Or 1x 2SK2145GR dual, wired in parallel.
Very close to 1x 2SK170BL, in every aspect.
NJFETs for Source Follower Applications
> On matching SOT devices
https://www.newark.com/peak/pca23/test-adapter-sot-23/dp/50AC8675
One time investment, or share cost in a group match action.
Patrick
These wee boards look amazing, thanks again Jack for your miniaturisation and Wayne too !
I’m in the UK trying to source some of the LSK389a and was referred onto Micross by Linear Systems but sadly Micross want me to place an order for a £250 minimum for 50 parts.
Anyone in Euro land found any better options ?
I may have to resort to my pal who is taking a holiday in the US [emoji848]
I’m in the UK trying to source some of the LSK389a and was referred onto Micross by Linear Systems but sadly Micross want me to place an order for a £250 minimum for 50 parts.
Anyone in Euro land found any better options ?
I may have to resort to my pal who is taking a holiday in the US [emoji848]
As Patrick (EUVL) has stated, Source and Drain of the 2SK209 are interchangeable. In the space allotted for the SOIC devices you can fit two of the 2SK209 or LSK170A. Note that two of the pads of the SOIC devices are are unconnected so you can jury-rig a connection. Sorry for the poor resolution:
Attachments
Not sure I understand right but.. would a correct synthesis of posts #133 and #137 be that 4x 2SK209GR (two couples in parallel) could be used in place of every and each LSK389B?
A single LSK389 is a dual Jfet. So one would use two 2SK209s, as shown in Jack's photo. Check out the data sheet for pinout info.
https://www.linearsystems.com/lsdata/datasheets/201122 - LSK389 Datasheet Rev A14 2018 06 14.pdf
https://www.linearsystems.com/lsdata/datasheets/201122 - LSK389 Datasheet Rev A14 2018 06 14.pdf
Ordered six of the Linear LSK389A SOIC JFETs from NAC to populate the two SOIC boards. I was able to get good matching within the six that I received. With the 10 ohm degeneration resistors the bias currents for the front end were 3.3 and 3.4 ma. Each JFET in the dual package measured within 0.1 ma.
The wattage on R9 ,the 499 ohm resistor is about 90 mW, good for 1/8 watt resistor.
The wattage on R9 ,the 499 ohm resistor is about 90 mW, good for 1/8 watt resistor.
