Datasheet

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SAMPLE NUMBER

TEMPERATURE (

LM95234 with

Filter On

LM95234 with

Filter Off

LM95234

SNIS136D –AUGUST 2006–REVISED MARCH 2013

www.ti.com

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 9 through Figure 11 describe the filter output in response to a step input and an impulse input.

Figure 9. Seventeen and fifty degree step response Figure 10. Impulse response with input transients

less than 4°C

Figure 11. Impulse response with input transients Figure 12. Digital Filter Response in a typical Intel

great than 4°C processor on a 65 nm or 90 nm process. The filter

curves were purposely offset for clarity.

Figure 12 shows the filter in use in a typical Intel processor on a 65/90 nm process system. Note that the two

curves have been purposely offset for clarity. Inserting the filter does not induce an offset as shown.

FAULT QUEUE

In order to suppress erroneous TCRIT1,TCRIT2 and TCRIT3 triggering the LM95234 incorporates a Fault Queue

for the unfiltered remote channels 3 and 4. The Fault Queue acts to ensure the remote temperature

measurement of these channels is genuinely beyond the corresponding Tcrit limit by not triggering until three

consecutive out of limit measurements have been made, see Figure 13 for an example. The Fault Queue

defaults on upon power-up. The fault queue for channels 3 and 4 can be turned ON or OFF via bits 0 and 1 of

the Configuration Register. When the fault queue is enabled, the TCRIT1, TCRIT2 and TCRIT3 pins will be

triggered if the temperature is above the Tcrit limit for 3 consecutive conversions and the corresponding mask bit

is 0 in the TCRIT Mask registers. Similarly the temperature needs to be below the Tcrit limit minus the hysteresis

value for three consecutive conversions for the TCRIT1, TRCIT2 and TCRIT3 pins to deactivate.

Product Folder Links: LM95234