emc2104 Standard Microsystems Corp., emc2104 Datasheet - Page 94

• Manufacturer Part Number: emc2104
• Description: Emc2104 Dual Rpm-based Pwm Fan Controller With Hardware Thermal Shutdown
• Manufacturer: Standard Microsystems Corp.

Example 1:
Example 2:
Example 3:
Revision 1.74 (05-08-08)
STEP #
SPEED
FAN
6
7
8
TEMPERATURE
EXTERNAL DIODE
1 TEMPERATURE
EXTERNAL
Note: The values shown in
DIODE 1
Table B.7 Fan Speed Determination for Example #2 (using settings in
(CPU)
75°C
75°C
75°C
100
(CPU)
80
90
o
o
programmable via SMBus.
o
C
C
C
Table B.6 Fan Speed Control Table Example #2 (continued)
THERMISTOR 2
140.375mV
235.125mV
THERMISTOR 2
VOLTAGE
READING
310mV
278.125mV
334.375mV
VOLTAGE
READING
306.25mV
(70°C)
(75°C)
(80°C)
Table B.6
DATASHEET
Dual RPM-Based PWM Fan Controller with Hardware Thermal Shutdown
TEMPERATURE
are example settings. All the cells in the look-up table are
TEMPERATURE
94
PUSHED
62°C
SETTING
PUSHED
48°C
58°C
55
60
65
o
o
o
C
C
C
INTERNAL DIODE
TEMPERATURE
INTERNAL DIODE
TEMPERATURE
(AMBIENT)
(AMBIENT)
58°C
58°C
58°C
65
70
75
o
o
o
C
C
C
Table
B.6)
CPU requires highest
Pushed Temperature
Thermistor requires
SETTING RESULT
0Ch (5120RPM) -
09h (6826 RPM)
09h (6826 RPM)
requires highest
SMSC EMC2104
(6144 RPM)
(6826 RPM)
(7680 RPM)
highest target
FAN DRIVE
TARGET
TACH
0Ah
target
target
09h
08h
Datasheet