RPM-Based Fan Controller with HW Thermal Shutdown
Datasheet
‘0’ (default) - the External Diode 2 channel high limit will not be linked to the SYS_SHDN pin. If the
temperature meets or exceeds the limit, the ALERT pin will be asserted normally.
‘1’ - the External Diode 2 channel high limit will be linked to the SYS_SHDN pin. If the temperature
meets or exceeds the limit then the SYS_SHDN pin will be asserted. The ALERT pin will be
asserted normally.
Bit 1 - SYS1 - Enables the high temperature limit for the External Diode 1 channel to trigger the Critical
/ Thermal Shutdown circuitry (see
‘0’ (default) - The External Diode 1 channel high limit will not be linked to the SYS_SHDN pin. If
the temperature meets or exceeds the limit, the ALERT pin will be asserted normally.
‘1’ - The External Diode 1 channel high limit will be linked to the SYS_SHDN pin. If the temperature
meets or exceeds the limit then the SYS_SHDN pin will be asserted. The ALERT pin will be
asserted normally.
Bit 0 - APD (EMC2103-2 only) - This bit enables the Anti-parallel diode functionality on the External
Diode 3 pins (DP3 and DN3).
‘0’ (default) - The Anti-parallel diode functionality is disabled. The External Diode 2 channel can be
configured for any type of diode
‘1’ - The Anti-parallel diode functionality is enabled. Both the External Diode 2 and 3 channels are
configured to support a diode or diode connected transistor (such as a 2N3904).
APPLICATION NOTE:
When the APD diode is enabled, there will be a delay of a full temperature update before
any comparisons and functionality associated with the External Diode 3 channel will be
implemented. This includes the SYS3 bit operation, limit comparisons, and look up table
comparisons.
The Configuration Register is software locked.
6.11
Configuration 2 Register
Table 6.15 Configuration 2 Register
ADDR
21h
R/W
R/W
REGISTER
Config 2
B7
-
B6
DIS_D
YN
B5
DIS_
TO
B4
DIS_
AVG
B3
B2
B1
B0
DEFAULT
0Eh
QUEUE[1:0]
CONV[1:0]
The Configuration 2 Register controls conversion rate of the temperature monitoring as well as the
fault queue.
Bit 6 - DIS_DYN - Disables the Dynamic Averaging Feature.
‘0’ (default) - The Dynamic Averaging function is enabled. The conversion time for all temperature
channels is scaled based on the chosen conversion rate to maximize accuracy and immunity to
random temperature measurement variation.
‘1’ - The Dynamic Averaging function is disabled. The conversion time for all temperature channels
is fixed regardless of the chosen conversion rate.
Bit 5 - DIS_TO - Disables the SMBus time out function.
‘0’ (default) - The SMBus time out function is enabled.
‘1’ - The SMBus time out function is disabled allowing the device to be fully I
2
C compliant.
Bit 4 - DIS_AVG - Disables digital averaging of the External Diode channels.
‘0’ (default) - The External Diode channels have digital averaging enabled. The temperature data
is the average of the previous four measurements.
Revision 0.85 (01-29-08)
48
SMSC EMC2103
DATASHEET
SMSC [ SMSC CORPORATION ]
