Hi all,

Does anyone know what the input impedance for the ADC of the LPC2103 is?

Also can anyone recommend a good book that explains USB 2.0?

Thanks in advance,
Charles Start a New Thread

Hello Charles,

> Also can anyone recommend a good book that explains USB 2.0?

have a look for USB books from Jan Axelson !
e.g. ISBN 1931448027
Directly from amazon:
http://www.amazon.de/exec/obidos/ASIN/1931448027/clibb
http://www.amazon.co.uk/exec/obidos/ASIN/1931448027/clibb
http://www.amazon.com/exec/obidos/ASIN/1931448027/clibb

He also has it own website with tons of information: www.lvr.com and a
detailed description of his books.
You can also find answers from him in forum of www.usb.org

Regards,

Martin Start a New Thread

Thank you Stefan for the information. It gives me a point of reference.

regards,
Charles

spoli58 wrote:
> The input impedance of the ADC of LPC2xxx cannot be found in their
> respective datasheets (I wonder why).
>
>
>
> The only indication is a note in the user manual (ADC chapter) that states
> the following:
>
>
>
> "It is suggested that RVSI is kept below 40 kohm."
>
>
>
> where RVSI is the impedance of the signal source. We can assume that the
> input impedance must be at least 10 times higher, i.e. > 400 kohm.
>
>
>
> I'm using this number in my application using LPC2136. I guess that LPC2103
> uses the same ADC input circuit and has a similar input impedance.
>
>
>
> Stefan
>
>
>
>
>
> _____
>
> From: l... [mailto:l...] On Behalf Of
> Charles R. Grenz
> Sent: February 22, 2008 11:51 AM
> To: l...
> Subject: [lpc2000] LPC2103 ADC input impedance
>
>
>
> Hi all,
>
> Does anyone know what the input impedance for the ADC of the LPC2103 is?
>
> Also can anyone recommend a good book that explains USB 2.0?
>
> Thanks in advance,
> Charles
>
>
>
>
>
>
> Start a New Thread

Thanks Martin for the information.

regards,
Charles

Martin Maurer wrote:
> Hello Charles,
>
>> Also can anyone recommend a good book that explains USB 2.0?
>
> have a look for USB books from Jan Axelson !
> e.g. ISBN 1931448027
> Directly from amazon:
> http://www.amazon.de/exec/obidos/ASIN/1931448027/clibb
> http://www.amazon.co.uk/exec/obidos/ASIN/1931448027/clibb
> http://www.amazon.com/exec/obidos/ASIN/1931448027/clibb
>
> He also has it own website with tons of information: www.lvr.com and a
> detailed description of his books.
> You can also find answers from him in forum of www.usb.org
>
> Regards,
>
> Martin
>
>
> Start a New Thread

The input impedance of the ADC of LPC2xxx cannot be found in their
respective datasheets (I wonder why).

The only indication is a note in the user manual (ADC chapter) that states
the following:

"It is suggested that RVSI is kept below 40 kohm."

where RVSI is the impedance of the signal source. We can assume that the
input impedance must be at least 10 times higher, i.e. > 400 kohm.

I'm using this number in my application using LPC2136. I guess that LPC2103
uses the same ADC input circuit and has a similar input impedance.

Stefan

_____

From: l... [mailto:l...] On Behalf Of
Charles R. Grenz
Sent: February 22, 2008 11:51 AM
To: l...
Subject: [lpc2000] LPC2103 ADC input impedance

Hi all,

Does anyone know what the input impedance for the ADC of the LPC2103 is?

Also can anyone recommend a good book that explains USB 2.0?

Thanks in advance,
Charles Start a New Thread