Lpc2000

Hello Lei,

The LPC2136 ADCs have their own power supply thru the Vdda and Vssa 
pins. As the datasheet specifies, you can go down to Vdda=2.5V and 
your ADCs will operate properly. However, keep in mind that the Vref 
level must not be higher than the Vdda, or your ADC will not yield 
correct results. 

The ADC operating conditions are: 
2.5V <= Vdda <= 3.6V and
2.0V <= Vref <= Vdda

The ADC chapter of the LPC2000 datasheets will be updated in future 
to reflect these details.

Regards,

Philips Apps Team



--- In lpc2000@yahoogroups.com, "fl429" <fl429@y...> wrote:
> The manual says, "This should be norminally the same voltage as 
Vdd but 
> should be isolated to minimize noise and err"
> 
> Does it mean that it will not work correctly if I apply a voltage 
lower 
> than Vdd ?
> 
> Thanks
> Lei  
> --- In lpc2000@yahoogroups.com, "fl429" <fl429@y...> wrote:
> > Hi, Folks,
> > 
> > Does it still work if I apply a lower voltage to the Vref (2.5V) 
than 
> > the norminal VDD (3.3V) ?
> > 
> > Any ideas? 
> > Thanks 
> > 
> > Lei