emc2105 Standard Microsystems Corp., emc2105 Datasheet - Page 48

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

ADDR
ADDR
14h
15h
16h
10h
Revision 1.74 (05-08-08)
6.5
6.6
R/W
R/W
R/W
R/W
R/W
R
The Pushed Temperature Registers store user programmed temperature values that can be used by
the look-up table to update the fan control algorithm. Data written in these registers is not compared
against any limits and must match the data format shown in
The Voltage Registers hold the data read from the TRIP_SET voltage input. The TRIP_SET voltage is
stored whether the TRIP_SET is used to set the Thermal / Critical Shutdown temperature or configured
to act as the VIN4 input.
Each bit weight represents mV of resolution so that the final voltage can be determined by adding the
appropriately set bits together.
The Beta Configuration Registers control advanced temperature measurement features for each
External Diode channel. The Beta Configuration Registers are software locked. The External Diode 1
Beta Configuration Register Is hardware locked if the SHDN_SEL pin is not set to disable the Critical
/ Thermal Shutdown functionality (see
Bit 4 - AUTO - Enables the Automatic Beta detection algorithm.
Bits 3 - 0 - BETAx[3:0] - hold a value that corresponds to a range of betas that the Beta Compensation
circuitry can compensate for. These four bits will always show the current beta setting used by the
circuitry. If the AUTO bit is set (default), then these bits may updated by the device with every
temperature conversion. If the AUTO bit is not set, then the value of these bits is used to drive the
Voltage Registers
Beta Configuration Registers
External Diode 1
External Diode 2
External Diode 3
Voltage / VIN4
Configuration
Configuration
Configuration
‘0’ - The Automatic Beta detection algorithm is disabled. The BETAx[3:0] bit settings will be used
to control the beta compensation circuitry.
‘1’ (default) - The Automatic Beta detection algorithm is enabled. The circuitry will automatically
detect the transistor type and beta values and configure the BETAx[3:0] bits for optimal
performance.
REGISTER
REGISTER
TRIP_SET
Voltage
Beta
Beta
Beta
400
Table 6.8 Beta Configuration Registers
B7
B7
-
-
-
Table 6.7 TripSet Voltage Register
200
B6
B6
-
-
-
DATASHEET
RPM-Based High Side Fan Controller with Hardware Thermal Shutdown
Table
100
B5
B5
48
-
-
-
6.1).
AUTO
AUTO
AUTO
B4
B4
50
B3
B3
Table
25
6.3.
13.5
B2
B2
BETA1[3:0]
BETA2[3:0]
BETA3[3:0]
6.25
B1
B1
SMSC EMC2105
3.125
B0
B0
Datasheet
DEFAULT
DEFAULT
FFh
10h
10h
10h