THDB-HTG poweron control pin. Not VCC in J2, J3 and J4

Honored Contributor

15 years ago

This post is a bit old but anyhow (This took me a full night to figure out):

The THDB-HTG comes in 2 variants:

HSTC version -> which has a female connector.

HSMC version -> which has a male connector.

(I'm still not 100% sure of this).

I have tested this solution with the HSMC version with the male connector:

and a Terasic DE115 board.

First you have to remove r14 (in the area next to the LED).

r14 short circuits 3V3 to the power on (HTSC pin 121).

This will disable the power to VCC33 and also 5V. on J2,J3,J4.file:///C:/Users/mib/Pictures/123CDPFQ/THDB-HTG_mod1.JPG

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Depending on which board you are using in the other end pin 121 on the HSMC female connector may be NC (every 3 pin in bank 3 on HSMC

is removed, as opposed to HSTC which has them all and also the power on signal well defined to pin 121).

So next step it to solder a wire to any working I/O port of your choice to pin 5 of the 1963A power regulator chip.

I used prototype connector 119 beside J3 connecting to (HSMC pin 119)

which has the signal name D[0] in my DE115 design.

You can now turn on VCC33 and 5V by setting this output(D[0]) to high.

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Good luck

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