How to use LPC4370FET100 HSADC in true differential mode?

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

How to use LPC4370FET100 HSADC in true differential mode?

566 Views
brandongallian
Contributor I

Hello,

I'm trying to set up the 12-bit ADC on the LPC4730FET100 (using LPC-Link2 as a demo board) to operate in true differential mode. I want to use ADCHS_0 (pin A2) as the positive end analog input, and ADCHS_NEG (pin A3) as negative end analog input. The only information I can find in the user manual says:  "It is possible to deselect the internal vin_neg and supply vin_neg externally at pin ADCHS_NEG by setting DCINNEG to 0. When only one input is used then the ADC can be used in true differential mode."  However, after setting DCINNEG = 0, ADCHS_NEG (pin A3) still outputs 0.5 volts. Is there something else I need to do to configure ADCHS_NEG as an input?

Thank you

Labels (2)
0 Kudos
1 Reply

399 Views
Hui_Ma
NXP TechSupport
NXP TechSupport

Hi,

The LPC4370 datasheet page143 with below description:

When DCINNEG is set to 1:

pastedImage_1.png

When DCINNEG is set to 0, provided voltage at ADCHS_NEG pin (ADCHS be used in true differential mode):

pastedImage_2.png

Wish it helps.


Have a great day,
Mike

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

0 Kudos