Lpc2000

Does anyone know what the A/D input impedance is on the LPC2129?  Or 
have experience using it with high impedance sources.

I had trouble finding info on the electrical specs of the ADC also, so 
I contact a Philips Apps Engineer.  He said "ADC pin input impediance 
is 20K to 39K Ohms"  Please note this was regarding the LPC2131, not 
the LPC2129, but I would think they would be similar.

I have been pretty successful so far with the ADC inputs, I am using 
five of them.  Some of the high impedance signals I had to scale so I 
used a single opamp buffer to scale the gain and stuck a 100 ohm 
series R at the output, it is performing quite well.

Hope that helps?
-Dave


--- In lpc2000@yahoogroups.com, "eden_eaj" <Bocote@u...> wrote:
> Does anyone know what the A/D input impedance is on the LPC2129?  Or 
> have experience using it with high impedance sources.