emc2105 Standard Microsystems Corp., emc2105 Datasheet - Page 49

• Manufacturer Part Number: emc2105
• Description: Emc2105 Rpm-based High Side Fan Controller With Hardware Thermal Shutdown
• Manufacturer: Standard Microsystems Corp.

ADDR
17h
RPM-Based High Side Fan Controller with Hardware Thermal Shutdown
Datasheet
SMSC EMC2105
6.7
AUTO
R/W
R/W
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
beta compensation circuitry. In this case, these bits should be set with a value corresponding to the
lowest expected value of beta for the PNP transistor being used as a temperature sensing device.
See
circuitry is disabled. In this condition, 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.
The REC Configuration Register determines whether Resistance Error Correction is used for each
external diode channel. The REC Configuration Register is software locked.
REC Configuration Register
Configuration
REGISTER
Table 6.9
X
3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
REC
for supported beta ranges. A value of 1111b indicates that the beta compensation
X
2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Table 6.9 Beta Compensation Look Up Table
BETAX[3:0]
B7
Table 6.10 REC Configuration Register
-
B6
-
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
X
DATASHEET
B5
49
-
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
X
B4
-
B3
-
Automatically detected
REC3
MINIMUM BETA
B2
Disabled
0.050
0.066
0.087
0.150
0.197
0.260
0.342
0.449
0.591
0.778
1.024
1.348
1.773
2.333
0.114
REC2
Revision 1.74 (05-08-08)
B1
REC1
B0
DEFAULT
07h