LM63CIMA National Semiconductor, LM63CIMA Datasheet - Page 11

• Manufacturer Part Number: LM63CIMA
• Manufacturer: National Semiconductor

Specifications of LM63CIMA

• Temperature Sensor Function: Temp Sensor
• Interface Type: Serial (2-Wire)
• Output Type: Digital
• Package Type: SOIC N
• Operating Temperature (min): 0C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Commercial
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Lead Free Status / Rohs Status: Not Compliant

1.8 COMMUNICATING WITH THE LM63
Each data register in the LM63 falls into one of four types of
user accessibility:
1.
2.
3.
4.
A Write to the LM63 is comprised of an address byte and a
command byte. A write to any register requires one data byte.
Reading the LM63 Registers can take place after the requisite
register setup sequence takes place. See Section 2.1.1 LM63
Required Initial Fan Control Register Sequence.
The data byte has the Most Significant Bit (MSB) first. At the
end of a read, the LM63 can accept either Acknowledge or
No-Acknowledge from the Master. Note that the No-Acknowl-
edge is typically used as a signal for the slave indicating that
the Master has read its last byte.
1.9 DIGITAL FILTER
The LM63 incorporates a user-configured digital filter to sup-
press erroneous Remote Temperature readings due to noise.
The filter is accessed in the Remote Diode Temperature Filter
and Comparator Mode Register. The filter can be set accord-
ing to the following table.
Level 2 is maximum filtering.
Read Only
Write Only
Read/Write same address
Read/Write different address
FIGURE 6. Step Response of the Digital Filter
D2
0
0
1
1
Digital Filter Selection Table
D1
0
1
0
1
Filter
No Filter
Level 1
Level 1
Level 2
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1.10 FAULT QUEUE
The LM63 incorporates a Fault Queue to suppress erroneous
ALERT triggering . The Fault Queue prevents false triggering
by requiring three consecutive out-of-limit HIGH, LOW, or
T_CRIT temperature readings. See
Queue defaults to OFF upon power-up and may be activated
by setting the RDTS Fault Queue bit in the Configuration
Register to a 1.
FIGURE 8. Digital Filter Response in an Intel Pentium 4
processor System. The Filter on and off curves were
purposely offset to better show noise performance.
FIGURE 7. Impulse Response of the Digital Filter
Figure
9. The Fault
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