2SK389BL IDSS too small
I had purchased one pair of 2SJ109BL and another pair of 2SK389BL from Littlediode.com on UK, they price is the more expensive on the market but it seems to me that they sell genuine JFETS.
After a 5 week shipping wait, I had received the JFETS for my UGS modules, the first was measuring IDSS using two multimeters and a single 9V battery using the schema on following picture, duplicated for this case:
The measurements I get are the following:
1) 2SJ109BL : 9.33mA & 9.21mA
2) 2SJ109BL : 9.70mA & 9.73mA
3) 2SK389BL : 7.15mA & 7.02mA
4) 2SK389BL : 3.59mA & 3.65mA
My problem is with the last one, its IDSS measurements are within GR grade as indicate Toshiba on the 2SK389 datasheet, but it’s labeled as BL grade. ¿Does this indicates that was a mistake at the factory when classifying the JFETS? ¿It’s common this type of mislabeled mistake? ¿Could be a fake or a relabeled JFET?
Thanks,
Alejandro
I had purchased one pair of 2SJ109BL and another pair of 2SK389BL from Littlediode.com on UK, they price is the more expensive on the market but it seems to me that they sell genuine JFETS.
After a 5 week shipping wait, I had received the JFETS for my UGS modules, the first was measuring IDSS using two multimeters and a single 9V battery using the schema on following picture, duplicated for this case:
The measurements I get are the following:
1) 2SJ109BL : 9.33mA & 9.21mA
2) 2SJ109BL : 9.70mA & 9.73mA
3) 2SK389BL : 7.15mA & 7.02mA
4) 2SK389BL : 3.59mA & 3.65mA
My problem is with the last one, its IDSS measurements are within GR grade as indicate Toshiba on the 2SK389 datasheet, but it’s labeled as BL grade. ¿Does this indicates that was a mistake at the factory when classifying the JFETS? ¿It’s common this type of mislabeled mistake? ¿Could be a fake or a relabeled JFET?
Thanks,
Alejandro
What you could do is buy 2SK170BLs and match them to your 2SJ109BL. Personally I would not use that last 2sk389BL in the UGS...The measurements I get are the following:
1) 2SJ109BL : 9.33mA & 9.21mA
2) 2SJ109BL : 9.70mA & 9.73mA
3) 2SK389BL : 7.15mA & 7.02mA
4) 2SK389BL : 3.59mA & 3.65mA
[…]
@Junie : Write the fusebit not help ? Do you write the atmel with crystalfont firmware ?What about Contrast control for lcd (pin 3?), did it using trimpot ?
Didiet
Hi didiet78, thanks for your reply.
The fusebit you mention is it like a "configuration and security bits"? it's part of the procedure in Ponyprog2000 which I select three boxes namely BODLEVEL, BODEN and SUT1.
I use the crystalfontz sw. the contrast if I'm not mistaken is taking care of AD8420.
One thing I wanted to know is if there's a problem with AD8420 does it affect the on/off state of ATMEL? the thing is why it's not responding to power switch even though the ATMEL is programmed successfully.
Cheers,
Junie
Hi didiet78, thanks for your reply.
The fusebit you mention is it like a "configuration and security bits"? it's part of the procedure in Ponyprog2000 which I select three boxes namely BODLEVEL, BODEN and SUT1.
I use the crystalfontz sw. the contrast if I'm not mistaken is taking care of AD8420.
One thing I wanted to know is if there's a problem with AD8420 does it affect the on/off state of ATMEL? the thing is why it's not responding to power switch even though the ATMEL is programmed successfully.
Cheers,
Junie
Junie , did you follow this procedure ?
Remember you have to load 2 files...the XX.eep and yyy.hex.
The on/off switch does have a delay...you have to press it for a while but remote is instantaneous.
Ofcourse play with the contrast...it might be on and contrast is off ! either way when on the led is brighter than on standby !
CV
Attachments
Finally it's working
a mistake in programming the microcontroller.
I should have selected the HEX file from the PROGRAM FLASH and EEP from DATA MEMORY, what I did previously is put hex and eep on the same PROGRAM FLASH.
Now it's Alive!! Thanks Didiet78 and Carlos, you keep my mind FRESH during the troublesome moments .
a mistake in programming the microcontroller.
I should have selected the HEX file from the PROGRAM FLASH and EEP from DATA MEMORY, what I did previously is put hex and eep on the same PROGRAM FLASH.
Now it's Alive!! Thanks Didiet78 and Carlos, you keep my mind FRESH during the troublesome moments .
Tell us how it sounds when you get it all together ....i already know but would like your opinion
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