LM99-1CIMM/NOPB National Semiconductor, LM99-1CIMM/NOPB Datasheet - Page 13

• Manufacturer Part Number: LM99-1CIMM/NOPB
• Description: IC REM DIODE TEMP SENSOR 8-MSOP
• Manufacturer: National Semiconductor

Specifications of LM99-1CIMM/NOPB

• Function: Hardware Monitor
• Topology: ADC (Sigma Delta), Comparator, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: 0°C ~ 125°C, External Sensor
• Output Type: SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: 0°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• For Use With: LM99-1EVAL/NOPB - BOARD EVALUATION LM99-1LM99-1EVAL - BOARD EVALUATION LM99-1
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM99-1CIMM; LM99-1CIMMNOPB; LM99-1CIMMNOPBTR; LM99-1CIMMNOPBTR; LM99-1CIMMTR

1.0 Functional Description
1.11 DIGITAL FILTER
In order to suppress erroneous remote temperature readings
due to noise, the LM99 incorporates a user-configured digital
FIGURE 9. Digital Filter Response in a Pentium 4 processor System. The filter on and off curves were purposely
D2
0
0
1
1
a) Step Response
D1
0
1
0
1
FIGURE 8. Filter Output Response to a Step Input
offset to better show noise performance.
No Filter
Level 1
Level 1
Level 2
Filter
(Continued)
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filter. The filter is accessed in the FILTER and ALERT CON-
FIGURE REGISTER at BFh. The filter can be set according
to the table shown.
Level 2 sets maximum filtering.
Figure 8 depict the filter output to in response to a step input
and an impulse input. Figure 9 depicts the digital filter in use
in a Pentium 4 processor system. Note that the two curves,
with filter and without, have been purposely offset so that
both responses can be clearly seen. Inserting the filter does
not induce an offset as shown.
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b) Impulse Response
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