Lpc2000

----- Original Message ----- 
From: "Ed Schlunder" <zilym@...>
To: <lpc2000@yahoogroups.com>
Sent: Monday, January 16, 2006 7:09 PM
Subject: [lpc2000] Building DIY wiggler w/74VHC08


> I'm thinking of building the DIY wiggler so that I can program and
> debug some LPC2103 chips on the cheap.
>
> I see the wiggler.txt schematic in the files area. It is using a
> 74AC244 chip to do voltage level conversion between the PC and the
> LPC21xx chip. It only seems to use 4 line drivers of the 74AC244 chip
> (half the chip is left unused).
>
> Would there be any problem with using a 74VHC08 quad 2 input AND gate
> chip instead? I would just tie one side of each AND gate high so that
> it can be used as 4 line drivers. This chip is cheaper and smaller
> than the 74AC244.
>
> The schematic also uses a DTC114 NPN transistor. I don't have any
> DTC114 transistors. Would MMBT3904 work okay instead?
>
> Any other tips for a DIY wiggler?

My version in jtag.zip definitely works!

What you propose should be OK. Don't forget to link pins 8 and 15 on the 
DB25 connector if you are using the Macraigor software.

Leon