In thermocouple measurement design, 50/60Hz noise impact the system measurement heavily. Even tried internal 50/60Hz filter in MAX31856 and other company's devices, the performance is not good enough. According to this situation, we recommend a glitch filte circuit which based on MAX4230. It has around 44dB attenuation for 50Hz. After adjust parameters, it can be used for 60Hz also.
This filter has been verified and got good system performance.