Hi Sreekanth, I would suggest that prior to connecting the load cell try to see if you are getting the same noise numbers as shown in the datasheet. These numbers are shown in Table 1 of the datasheet. These numbers are with no averaging. Averaging may be masking the problem. Short the inputs together and bias the short to mid-AVDD supply. You can use a voltage divider with two 10k Ohm resistors, then connect the shorted inputs at the junction of the resistors. This is important to check as any PCB layout or external noise may become more evident. Your best case noise is with the inputs shorted. From your schematic you show using a boost mode converter to generate your supply voltage. These types of converters have a great deal of switching transients. For this type of supply we commend boosting the supply slightly above the desired voltage then followed by a low noise LDO linear supply. This will help reduce the switching transients from affecting the analog performance of the ADC. Also, PCB layout is very important to prevent switching noise from getting into the ADC. A solid ground plane (as opposed to just ground connection traces) is also important. Due to the transients, I believe that a lot of the drift affects you are seeing are related to filtering the transients. Ideally you want to make a ratiometric measurement where the excitation voltage and the reference voltage are the same. In your schematic the filtering is quite different between the load cell and reference. As the filter for the reference is very heavy, any changes or transients may take some time to recover. Because of your switching regulator, your schematic is much different than the ADS1232REF which uses a low-noise LDO regulating a higher voltage to 5V and is very stable. You may find that the performance will actually improve by reducing the filtering to something much smaller. You may also want to add some resistance (100 to 1k Ohm) in series with your analog inputs from the load cell to help reduce any external noise. Best regards, Bob B
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