JAJSAR0B March 2007 – October 2017 LM95214
PRODUCTION DATA.
To suppress erroneous remote temperature readings due to noise as well as increase the resolution of the temperature, the LM95214 incorporates a digital filter for Remote 1 and 2 Temperature Channels. When a filter is enabled the filtered readings are used for the TCRIT comparisons. There are two possible digital filter settings that are enabled through the Filter Setting Register at register address 0Fh. The filter for each channel can be set according to the following table:
| R1F[1:0] OR R2F[1:0] | FILTER SETTING | |
|---|---|---|
| 0 | 0 | No Filter |
| 0 | 1 | Filter (equivalent to Level 2 filter of the LM86/LM89) |
| 1 | 0 | Reserved |
| 1 | 1 | Enhanced Filter (Filter with transient noise clipping) |
Figure 11, Figure 12, and Figure 13 describe the filter output in response to a step input and an impulse input.
Figure 11. Seventeen and Fifty Degree Step Response
Figure 13. Impulse Response With Input Transients Greater Than 4°C
Figure 12. Impulse Response With Input Transients Less Than 4°C
Figure 14. Digital Filter Response in a Typical Intel Processor on a 65 nm or 90 nm Process. The Filter Curves Were Purposely Offset for Clarity.
Figure 14 shows the filter in use in a typical system. Note that the two curves have been purposely offset for clarity. Inserting the filter does not induce an offset as shown.