ADC delta sigma error reading.

[Anonymous]

I need to design a closed-loop control system but i have this problem:

Every 10 samples of ADC delta sigma this noise contaminates the signal.

Does anyone know how to solve this problem?

Samlple Rate: 1 kHz.

Clock Source: External

Thanks for Listening

[odissey1 · Accepted solution]

ls.manoel,

You didn't describe electrical part of the system. Is this a temperature control using thermistor? If you are using PWM control (e.g. thermo-electric cooler control or a heater) I believe that spikes come from the sensor (thermistor) input electrical interference with PWM pulses. If so, try to separate/shield thermistor wires and PWM output wires. Additional capacitor on the input should help also.

If nothing works, add simple 3-point median filter to cut out spikes from the sampled signal:

Re: Feature request: add Median Filter component to Digital Filter component

/odissey1