EMC1002_06 Datasheet, PDF (11/22 Pages) SMSC Corporation – 1°C Dual SMBus Sensor with Resistance Error Correction

1°C Dual SMBus Sensor with Resistance Error Correction
Datasheet
ACTUAL TEMP.
(°C)
-63
Table 4.1 Temperature Data Format
DEFAULT RANGE
BINARY
0000 0000 000 Note 4.1
EXTENDED RANGE
OFFSET BINARY
0000 0001 000 Note 4.2
-0.125
0
+0.125
+0.250
0000 0000 000 Note 4.1
0000 0000 000 Note 4.1
0000 0000 001
0000 0000 010
0011 1111 111
0100 0000 000
0100 0000 001
0100 0000 010
+1
0000 0001 000
0100 0001 000
+127
+128
0111 1111 000 Note 4.3
0111 1111 000 Note 4.3
1011 1110 000
1011 1111 000
+190
+191
0111 1111 000 Note 4.3
0111 1111 000 Note 4.3
1111 1110 000
1111 1111 000 Note 4.4
Note 4.1 Data in Binary Format reads 0000 0000 000 for all temperatures ≤ 0.00°C.
Note 4.2 Data in Offset Binary Format reads 0000 0000 000 for all temperatures ≤ -64°C.
Note 4.3 Data in Binary Format reads 0111 1111 000 for all temperatures ≥ +127°C.
Note 4.4 Data in Offset Binary Format reads 1111 1111 000 for all temperatures ≥ +191°C.
The 11-bit temperature data is stored with the 8 most significant bits stored in the High Byte register
and the 3 least significant bits in the Low Byte register. The Low Byte register contains the three least
significant bits as outlined in Table 4.2. These bits are stored in the upper three bits of the register,
and the five LSB positions of this register always read zero. In Table 4.2, the upper case “B” shows
the bit position of a 16-bit word created by concatenating the High Byte and Low Byte, and the lower
case “b” shows the bit position in the 11-bit temperature data. The resolution of the internal temperature
is 0.5°C and the b1 and b0 bits of the Internal Temperature Value Low Byte register will always read 0.
Table 4.2 Bit Position of Two Byte Values
HIGH BYTE
LOW BYTE
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0 0
0
0
0
0
4.5
ALERT/THERM2 Output
The ALERT/THERM2 output asserts if an out of limit measurement is detected as described in 4.12,
"Limit Registers," on page 15. The ALERT/THERM2 pin is an open drain output and requires a pull-up
resistor to V_DD.The ALERT/THERM2 pin can be used as an SMBALERT#, or may be configured as a
second THERM output.
As described in the SMBus specification, an SMBus slave may inform the SMBus master that it wants
to talk by asserting the SMBALERT# signal. One or more ALERT outputs can be hardwired together
as a wired-or bus to a common input.
SMSC EMC1002
11
DATASHEET
Revision 1.3 (03-24-06)