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Altera apex 20k200e FPGA question

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dannyngweekiat_85

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I have a problem regarding this board. Its on the jp12 which is suppose to be a 5v prototype port. It suppose to output 5v but then the port only put out 3.3v. so how suppose to drive the output to 5 excpet for adding an external converter? The LCD i am driving need at least 0.7Vdd for high signal which is around 3.5. Can anyone help me out on this?
 

sp

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@ltera apex 20k200e FPGA question

ur apex board hav 2 voltages compatible expansion port... use the 5V expansion port... it will b ok then...

remember to pull low (enable) the V7 pin on the board to enable to expansion port.

regards,
sp
 

dannyngweekiat_85

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yup... i am using the 5v io pin. the output voltage still is at 3.3. As for V7 if i pull it low... This is what i did. Inside program i do V7 <= '0' where v7 is mapped to the v7 pin. When switch it to 1 the whole port wont function. As for the output voltage i still get aroung 3.2 to 3.3... Wat i did wrong :?:
 

sp

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@ltera apex 20k200e FPGA question

emm.. u just use it for 5v i/o.. dont worry it works.. 3.2 to 3.3V is high enuff to drive ur 5V logic...

regards,
sp
 

dannyngweekiat_85

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icic. So as for the driving of LCD. U done b4? can it be drive using the 5v port? the datasheet specific that it need 3.5 at least to indicate high. I am using an apex 20K200efc484-2X board. Have any experience on it?

Thanks for ur support till now.
 

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@ltera apex 20k200e FPGA question

actually for ur question... the LCD u just connect it to the board and using the reference design come wth the apex board (or the tutorial)... the LCD is already functioning perfectly...

anyway... i will ask for u regarding the voltage level... i also start to wonder even my old flex10k board, when i use the voltmeter to check the voltage, the high voltage is also 3.3V...

i will let u know later...

regards,
sp
 

dannyngweekiat_85

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icic. thx very much hope to hear from u soon. Too bad i got my own LCD... din use the one that come with the board... :(

Added after 2 hours 6 minutes:

I foung the ic datasheet i c for the Voltage translator h++p://www.alldatasheet.com/datasheet-pdf/pdf/65947/IDT/IDTQS3384Q.html

It seems that it translate 5 to 3.3 but not 3.3 to higher. So we have to and another convertor to it?
 

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@ltera apex 20k200e FPGA question

first... i think u try the LCD come wth the dev. board... see if it works... it should b, but u get the output voltage is around 3.3V which is quite weird... i think it should b 3.5 and above... please check again...

i still couldn't get any answer for low i/o voltage.. i check my UP2 i/o and it is also a 3.5V for high and not 5V.. but it works on all the 5V IC... so it shouldn't b any prob...except ur dev. board has some prob..

sure there is 3.3-5V IC converter out there.. just search again... use 2 common emitters configuration wth voltage divider at the input stage can achieve tht as well...

i'll let u know if i hav more info regarding ur low output voltage...

regards,
sp
 

dannyngweekiat_85

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thanks very much for the info.. i will try that. I also try to check with people and see wether there are any cause to it.. thx very much.
 

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