RPM-Based Fan Controller with HW Thermal Shutdown
Datasheet
When the Beta Compensation circuitry is disabled, the diode channels will function with default current
levels and will not automatically adjust for beta variation. This mode is used when measuring a discrete
2N3904 transistor or AMD thermal diode.
All of the Beta Configuration Registers are Software Locked.
Table 6.13 Beta Compensation Look Up Table
BETAX[2:0]
2
1
0
MINIMUM BETA
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0.1111
0.1765
0.25
0.333 (default)
0.4285
1.0
2.333
Disabled
6.10
REC Configuration Register
Table 6.14 REC Configuration Register
B7 B6 B5 B4 B3 B2
REC3 REC2
ADDRESS
32h
REGISTER
B1
B0
DEFAULT
REC
Configuration
-
-
-
-
-
REC1
07h
The REC Configuration Register determines whether Resistance Error Correction is used for each
external diode channel. The REC Configuration Register is software locked.
If either the External Diode 1 channel or External Diode 3 channel is selected by the SHDN_SEL pin
to be the hardware shutdown input channel (see Table 5.4), then the corresponding RECx bit will be
locked. Writing to the bit will have no affect and reading from it will always report the current setting.
Bit 2 - REC3 - Controls the Resistive Error Correction functionality of External Diode 3
‘0’ - the REC functionality for External Diode 3 is disabled
‘1’ (default) - the REC functionality for External Diode 3 is enabled.
Bit 1 - REC2 - Controls the Resistive Error Correction functionality of External Diode 1
‘0’ - the REC functionality for External Diode 2 is disabled
‘1’ (default) - the REC functionality for External Diode 2 is enabled.
Bit 0 - REC1 - Controls the Resistive Error Correction functionality of External Diode 1
‘0’ - the REC functionality for External Diode 1 is disabled
‘1’ (default) - the REC functionality for External Diode 1 is enabled.
SMSC EMC2102
Revision 1.95 (10-19-06)
DATA3S9HEET
SMSC [ SMSC CORPORATION ]
