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Adaptor for USB Blaster II to USB Blaster header


We have a board designed for the original USB Blaster. The connector for the USB Blaster II is slightly larger. Is there an adaptor available that would allow us to connect the USB Blaster II into a shrouded header that can only accept the USB Blaster connector?

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5 Replies
Valued Contributor II

Not sure what you mean by "slightly larger"?

Was your original board built with a 2mm spacing 2x5 header instead of a 2.54mm (100mil) spacing header (I have seen this)?


Both the original USB Blaster and the newer USB BlasterII use a standard 100mil spacing 2x5 header.

If it is shrouded, it must have the polarity notch in the correct orientation.

Unshrouded also works, just need to insure pin1 orientation of connectors align.


I have the data sheets all the way back to the ByteBlasterMV from 1999 and the ISP connector is always
listed as being a 2x5 100mil standard female connector that is 250mil wide by 700mil long.

Same dimensions for all the ByteBlasterXX and USBBlasterXX variations.


You may need to send a photo of what does not fit.

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Valued Contributor III
Agree with the above. All Intel and third Party dev boards as well as our own design have a JTAG connector fitting both USB Blaster versions. It's true that the USB Blaster version with FPC cable uses a connector without polarity notch, never noticed it would be smaller than standard 0.1" connector.
Anyway, there are male IPC connectors on the market, you can make your own adapter.
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Here's a photo of the USB Blaster vs USB Blaster II connectors:

USB Blaster vs USB Blaster II.png


Here's a photo of the USB Blaster mated to our board. The shrouded connector just fits the USB Blaster connector. There's no room for the wider USB Blaster II connector:

USB Blaster w shrouded header.png


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Valued Contributor II

Well, I have measured all the 2x5 100mil headers I have on all my different FPGA programming boards and the inside dimension of the boxed header comes out to be 700mil X 250mil. So the 'standard' 2x5 female header fits perfectly. I have third party USB Blaster clones, a TerASIC USB Blaster, and an original ByteBlasterII (ie, LPT port to 10pin header). All are exactly the same female 2x5 connector.

Both the 2018 and 2022 versions of the Altera/Intel USB BlasterII user document call out the connector as 240mil x 700mil:


So I would postulate that your board has 2x5 pin male shrouded header that is 500mil wide, expecting to be used with
a 500mil wide female header, as you might see from breakaway header strips.

You will either need to modify the board and replace the non-standard connector, or if that is not possible due to mechanical
fit issues, build an adapter cable. Source a female 2x5 flat cable connector that fits in your socket (if you can ... IDK) and then
attach it to a short 10wire IDE cable with a 10pin box header male connector that is 'standard size' of 250x700mil.

Or make a little PCB with the two 2x5 100mil footprints and source a female  board mount connector that matches your
board mount male connector and use a standard 2x5 100mil male boxed header as the other connector.

Or if you can't find female connectors that mate with your male boxed header, get out a dremel tool and make some from standard
female connectors by cutting/grinding them down to size.

And whoever designed your original board and used a non standard header owes you a real nice dinner...

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All replies above are correct. The USB Blaster and USB Blaster II should fit the same board. Hence, the solutions that have been mention by our community users can be apply to your case.



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