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Electronics => AVR, 8051 Family and ARM Area => Topic started by: zaalzaalak on July 26, 2010, 09:50:53 09:50



Title: LPC1768 ADC REF
Post by: zaalzaalak on July 26, 2010, 09:50:53 09:50
Can I connect a 2.5V reference voltage to VREFP,and then connect VREFN to GND ? Is this working for LPC1768 ADC?
or I should connect VREFP to 3.3V supply and VREFN to GND?

Please help me.


Title: Re: LPC1768 ADC REF
Post by: jestanoff on July 27, 2010, 07:46:33 19:46
Both options are possible but the accuracy of the ADC and DAC are dependent on fluctuations of voltage between these two pins. So unless you need high precision measurement use 3.3v power supply with L/C appropriate filter.


Title: Re: LPC1768 ADC REF
Post by: ktek on October 21, 2010, 09:11:58 21:11
in some cases is better to connect VREFP to 3.3v power supply, with own voltage fluctuations
Eg when you measure ratiometric sensor supply by 3.3 V
like potentiometer, straig gauge brige, passive pressure sensor  etc.
Fox mixed application (ratiometric nonratiometric) is useful to measure  3.3V too
and refer it all nonratiometri measures