Lpc2000

----- Original Message ----- 
From: "Aalt Lokhorst" <lokhorst@...>
To: <lpc2000@yahoogroups.com>
Sent: Friday, April 08, 2005 11:26 AM
Subject: Re: [lpc2000] Re: Wiggler with LPC2124


>
> Hello Leon,
> I am using your circuit without problems. I had only one issue.
>
> In your schematic is a HC244 buffer. The problem with this one, at least
> with the Philips type, it is not 5V tolerant. If it is powered by 3.3V
> then the inputs should not exceed 3.3V. It depends on the LPT port if
> this will happen. I think the LVC244 is a better choice just in case the
> LPT port delivers strong 5V levels. I have seen situations where the
> 3.3V of the circuit was lifted by the voltage from the LPT port.
> (Because of the diodes between the input and the VCC in the HC device)

I just checked the voltages on my port and they were about 4.8 V, but I 
haven't had any problems; I used the Philips part, but all HC parts should 
be the same. I'll amend the design, anyway.


>
> We are using the Rowley CrossWorks software.
> (Nice software and very fast responding support people)

I use their software as well.

Leon
--
Leon Heller, G1HSM
http://www.geocities.com/leon_heller