Dual RPM-Based PWM Fan Controller with Hardware Thermal Shutdown
Datasheet
The Critical / Thermal Shutdown temperature has a separate fault queue that applies to the selected
hardware shutdown channel (see Section 6.1.1) when compared against the threshold set by the
TRIP_SET pin.
APPLICATION NOTE: If the fault queue for any channel is currently active (i.e. an out of limit condition has been
detected and caused the fault queue to increment) then changing the settings will not take
effect until the fault queue is zeroed. This occurs by the ALERT# pin asserting or the out of
limit condition being removed.
Table 6.14 Fault Queue
QUEUE[1:0]
1
0
NUMBER OF CONSECUTIVE OUT OF LIMIT CONDITIONS
0
0
1
1
0
1
0
1
1 (disabled)
2
3
4 (default)
Bit 1 - 0 - CONV[1:0] - determines the conversion rate of the temperature monitoring. This conversion
rate does not affect the fan driver. The supply current from VDD_3V is nominally dependent upon the
conversion rate and the average current will increase as the conversion rate increases.
Table 6.15 Conversion Rate
TEMPERATURE OVER SAMPLING
CONV[1:0]
FROM 11 BITS
1
0
CONVERSION RATE
DYN_DIS = ‘0’
DYN_DIS = ‘1’
0
0
1
1
0
1
0
1
1 / sec
2 / sec
x8
x4
x2
x1
x1
x1
x1
x1
4 / sec (default)
Continuous
6.11
Configuration 3 Register
Table 6.16 Configuration 3 Register
ADDR
22h
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
00h
VIN4_I
NV
VIN3
_EN
VIN3
_INV
VIN2
_EN
VIN2
_INV
VIN1
_EN
VIN1
_INV
R/W
Config 3
-
The Configuration 3 Register controls the four voltage input channels. This register is software locked.
Bit 6 - VIN4_INV - Determines whether the VIN4 channel data is inverted.
‘0’ (default) - The VIN4 channel data is not inverted.
SMSC EMC2104
Revision 1.74 (05-08-08)
DATA5S7HEET
SMSC [ SMSC CORPORATION ]
