LM95233_07 NSC [National Semiconductor], LM95233_07 Datasheet - Page 11

• Manufacturer Part Number: LM95233_07
• Description: Dual Remote Diode and Local Temperature Sensor with SMBus Interface and TruTherm Technology
• Manufacturer: NSC [National Semiconductor]

1.2 POWER-ON-DEFAULT STATES
LM95233 always powers up to these known default states.
The LM95233 remains in these states until after the first con-
version.
1.
2.
3.
4.
5.
6.
7.
8.
FIGURE 1. Conversion Rate Effect on Power Supply
Output Pin
All Temperature readings set to 0°C until the end of the
first conversion
Diode Model Select: Remote 1 set to 65 nm Intel
processor, Remote 2 set to MMBT3904
Remote offset for all channels 0°C
Configuration: Active converting
Continuous conversion with all channels enabled,
time = 1s
Enhanced digital filter enabled for Remote 1 and 2
Status Registers depends on state of thermal diode
inputs
Local and Remote Temperature Limits for TCRIT1,
TCRIT2 and TCRIT3 outputs:
TCRIT1
TCRIT2
TCRIT3
Remote 2
Masked,
(°C)
110
85
85
Temperature Channel Limit
Current
Remote 1
Masked,
(°C)
110
85
85
20206306
Masked,
Masked,
Local
(°C)
85
85
85
11
9.
10. Revision ID set to 79h
1.3 SMBus INTERFACE
The LM95233 operates as a slave on the SMBus, so the
SMBCLK line is an input and the SMBDAT line is bidirectional.
The LM95233 never drives the SMBCLK line and it does not
support clock stretching. According to SMBus specifications,
the LM95233 has a 7-bit slave address. Three SMBus device
address can be selected by connecting A0 (pin 6) to either
Low, Mid-Supply or High voltages. The LM95233 has the fol-
lowing SMBus slave address:
1.4 TEMPERATURE CONVERSION SEQUENCE
Each of the3 temperature channels of LM95233 can be turned
OFF independent from each other via the Channel Enable
Register. Turning off unused channels will increase the con-
version speed in the fastest conversion speed mode. If the
slower conversion speed settings are used, disabling unused
channels will reduce the average power consumption of
LM95233.
1.5 DIGITAL FILTER
In order to suppress erroneous remote temperature readings
due to noise as well as increase the resolution of the temper-
ature, the LM95233 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:
Figure 2 describes the filter output in response to a step input
and an impulse input.
A0 Pin State
R1F[1:0] or R2F[1:0]
Mid-Supply
Manufacturers ID set to 01h
0
0
1
1
High
Low
0
1
0
1
SMBus Device Address A[6:0]
Hex
2Ah
2Bh
18h
Filter (equivalent to Level 2
Enhanced Filter (Filter with
filter of the LM86/LM89)
transient noise clipping)
Filter Setting
Reserved
No Filter
001 1000
010 1010
010 1011
Binary
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