[TI-H] Re: Calc Port Voltage
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[TI-H] Re: Calc Port Voltage
Shyam,
Ok scratch the last idea because I found what you need.
Apparently Phillips (creators of the I2C bus) have had the same problem.
The idea I mentioned before would require that the IC you are using be
5V tolerant. And unless the spec says so I will assume it is not! The
following link is to an APP note for a single MOSFET, which apparently
will do everything needed. It even includes protection for the 3V
device from voltage spikes of the 5V device. Hopefully this will make
design a cinch. I didn't read the whole appnote and have not looked at
the data sheet for the device but I would not expect it to draw too much
current, although you will probably need to use a 9V battery and make a
voltage divider circuit to supply 3V and 5V to the system. I am going
to buy a few of these MOSFETs soon for a project I am working on. Let
me know if you get them, or I will reply once I see how well they work.
-Cullen-
-----Original Message-----
From: ti-hardware-bounce@lists.ticalc.org
[mailto:ti-hardware-bounce@lists.ticalc.org] On Behalf Of Shyam
Dwaraknath
Sent: Sunday, August 18, 2002 2:39 PM
To: ti-hardware@lists.ticalc.org
Subject: [TI-H] Re: Calc Port Voltage
Here are the circuits. I just took them from another site cause I was
spending most of my time designing the circuits for the Xe1202. Step
<http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/s2000/pete
rdan/stepup.jpg> Up Step
<http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/s2000/pete
rdan/stepdown.jpg> Down
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