Fan Control Device with High Frequency PWM and Temperature Monitors
Datasheet
Table 8.18 Voltage Limits vs. Register Setting
REGISTER
SETTING AT
NOMINAL
REGISTER
SETTING AT
MAXIMUM
VOLTAGE
REGISTER
SETTING AT
VOLTAGE MINIMUM VOLTAGE
NOMINAL
INPUT VOLTAGE
MAXIMUM
VOLTAGE
MINIMUM
VOLTAGE
Vccp
VCC
2.25V
3.3V
C0h
C0h
3.00V
4.38V
FFh
FFh
0V
0V
00h
00h
8.2.11
Registers 4E-53h: Temperature Limit Registers
Table 8.19 Registers 4E-53h: Temperature Limit Registers
Register
Address
Read/
Write
Bit 7
(MSb)
Bit 0
(LSb)
Default
Value
Register Name
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
4Eh
4Fh
50h
51h
52h
53h
R/W
R/W
R/W
R/W
R/W
R/W
Remote Diode 1 Low Temp
Remote Diode 1 High Temp
Internal Low Temp
7
7
7
7
7
7
6
6
6
6
6
6
5
5
5
5
5
5
4
4
4
4
4
4
3
3
3
3
3
3
2
2
2
2
2
2
1
1
1
1
1
1
0
0
0
0
0
0
81h
7Fh
81h
7Fh
81h
7Fh
Internal High Temp
Remote Diode 2 Low Temp
Remote Diode 2 High Temp
Setting the Lock bit has no effect on these registers.
If an external temperature input or the internal temperature sensor either exceeds the value set in the
high limit register or is less than or equal to the value set in the low limit register, the corresponding
bit will be set automatically by the EMC2300 in the Interrupt Status Register 1 (41h). For example, if
the temperature reading from the Remote1- and Remote1+ inputs exceeds the Remote Diode 1 High
Temp register limit setting, Bit[4] D1 of the Interrupt Status Register 1 will be set. The temperature limits
in these registers are represented as 8 bit, 2’s complement, signed numbers in Celsius, as shown
below in Table 8.20.
Table 8.20 Temperature Limits vs. Register Settings
TEMPERATURE
LIMIT (DEC)
LIMIT (HEX)
-127°c
-127
81h
.
.
.
.
.
.
.
.
.
-50°c
-50
CEh
.
.
.
.
.
.
.
.
.
0°c
0
00h
.
.
.
.
.
.
.
.
.
50°c
50
32h
.
.
.
.
.
.
.
.
.
127°c
127
7Fh
Revision 0.2 (06-14-06)
SMSC EMC2300
DATA5S8HEET
SMSC [ SMSC CORPORATION ]
