Datasheet

Remote 4
Tcrit Limit
Register
Value
Status 4
Register
R4T3 Bit
Remote 4 Temperature Readings
SAMPLE NUMBER
n
n+1
n+2
n+3
n+4
n+5
n+6
n+7
n+8
n+9
n+10
n+11
LM95214
SNIS146A MARCH 2007REVISED MARCH 2013
www.ti.com
FAULT QUEUE
In order to suppress erroneous TCRIT1,TCRIT2 and TCRIT3 triggering the LM95214 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 11 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, TCRIT2 and TCRIT3 pins to deactivate.
Figure 11. Fault Queue Response Diagram (with 0°C hysteresis)
TEMPERATURE DATA FORMAT
Temperature data can only be read from the Local and Remote Temperature value registers. The data format for
all temperature values is left justified 16-bit word available in two 8-bit registers. Unused bits will always report
"0". All temperature data is clamped and will not roll over when a temperature exceeds full-scale value.
Remote temperature data for all channels can be represented by an 11-bit, two's complement word or unsigned
binary word with an LSb (Least Significant Bit) equal to 0.125°C.
Table 1. 11-bit, 2's complement (10-bit plus sign)
Temperature Digital Output
Binary Hex
+125°C 0111 1101 0000 0000 7D00h
+25°C 0001 1001 0000 0000 1900h
+1°C 0000 0001 0000 0000 0100h
+0.125°C 0000 0000 0010 0000 0020h
0°C 0000 0000 0000 0000 0000h
0.125°C 1111 1111 1110 0000 FFE0h
1°C 1111 1111 0000 0000 FF00h
25°C 1110 0111 0000 0000 E700h
55°C 1100 1001 0000 0000 C900h
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