EMC1422 Datasheet, PDF (22/36 Pages) SMSC Corporation – 1C Temperature Sensor with Hardware Thermal Shutdown

1°C Temperature Sensor with Hardware Thermal Shutdown
Datasheet
I_LOW
I_HIGH
Substrate
PNP
Resistance
Error
Correction
DP
Anti-
Aliasing
Filter
ΔΣ
ADC
DN
Figure 5.6 Block Diagram of Temperature Monitoring Circuit
5.11
Temperature Measurement Results and Data
The temperature measurement results are stored in the internal and external temperature registers.
These are then compared with the values stored in the high and low limit registers. Both external and
internal temperature measurements are stored in 11-bit format with the eight (8) most significant bits
stored in a high byte register and the three (3) least significant bits stored in the three (3) MSB
positions of the low byte register. All other bits of the low byte register are set to zero.
The EMC1422 has two selectable temperature ranges. The default range is from 0°C to +127°C and
the temperature is represented as binary number able to report a temperature from 0°C to +127.875°C
in 0.125°C steps.
The extended range is an extended temperature range from -64°C to +191°C. The data format is a
binary number offset by 64°C. The extended range is used to measure temperature diodes with a large
known offset (such as AMD processor diodes) where the diode temperature plus the offset would be
equivalent to a temperature higher than +127°C.
Table 5.3 shows the default and extended range formats.
TEMPERATURE (°C)
Diode Fault
-64
-1
0
0.125
Revision 1.16 (03-15-07)
Table 5.3 EMC1422 Temperature Data Format
DEFAULT RANGE 0°C TO 127°C
000 0000 0000
000 0000 0000
000 0000 0000
000 0000 0000
Note 5.1
000 0000 0001
EXTENDED RANGE RANGE -64°C
TO 191°C
000 0000 0000
000 0000 0000
Note 5.2
001 1111 1111
010 0000 0000
010 0000 0001
22
DATASHEET
SMSC EMC1422