1°C Triple SMBus Sensor with Resistance Error Correction
Datasheet
Bit 6 initiates ADC conversions. When this bit is low, the ADC will convert temperatures in a
continuous mode. When this bit is high, the ADC will be in standby mode, thus reducing supply
current significantly though the SMBus will still be active. If bit 6 is 1 and the one-shot register is
written to, the ADC will execute a temperature measurement and then return to standby mode.
Bit 5 sets the ALERT/THERM2 pin to act as either an SMBALERT# signal or as the THERM2 signal. If
bit 5 is set to 1 the ALERT/THERM2 pin acts as the THERM2 signal and bit 7 is ignored.
Bit 2 selects the range and format of the temperature as shown in Table 4.1, “Temperature Data
Format,” on page 11
Bit 0 enables the anti-parallel diode (remote 2 diode). If bit 0 is set to 0, the internal, remote 1 and
remote 2 zones are active. This mode of operation is not compatible with substrate transistors such
as those commonly used in CPUs. When bit 0 is set to 1, only the internal and remote 1 zones are
active, and a substrate transistor may be used on remote 1.
4.12
Conversion Rate Register
The conversion rate register determines how many times the temperature value will be updated per
second. The lowest 4 bits configure a programmable delay that waits between consecutive conversion
cycles to obtain the desired conversion rate. Table 4.7 shows the conversion rate and the associated
quiescent current.
Table 4.7 Conversion Rates
CONVERSION RATE
VALUE
CONVERSIONS/SECOND
TYPICAL QUIESCENT CURRENT (μA)
00h
01h
0.0625
47
0.125
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
02h
0.25
03h
0.5
04h
1
05h
2
06h
4
07h
8
16
08h
09h
32
0Ah
64
0Bh to FFh
Reserved
4.13
Limit Registers
The EMC1033 compares the limit registers to the measured temperature. The data format of the
programmed limits for this comparison is the same as the measurement data format determined by
the Configuration Register. The user is required to update the limit registers to the new format when
changing between measurement data formats.
The user can configure high and low temperature limits and an independent THERM limit. The
temperature high limit (TH) is an 11-bit value that is set by the Temperature High Limit High Byte
register and the Temperature High Limit Low Byte register. The Temperature High Limit Low Byte
register contains the three least significant bits as shown in Table 4.2 on page 11.
The temperature low limit (TL) is an 11-bit value that is set by the Temperature Low Limit High Byte
register and the Temperature Low Limit Low Byte register as shown in Table 4.2 on page 11.
SMSC EMC1033
Revision 1.1 (01-19-07)
DATA1S7HEET
SMSC [ SMSC CORPORATION ]
