EMC6D103-CZC SMSC, EMC6D103-CZC Datasheet - Page 70

• Manufacturer Part Number: EMC6D103-CZC
• Description: Industrial Temperature Sensors Auto Fan Contrllr Up to 4 Fans
• Manufacturer: SMSC

Specifications of EMC6D103-CZC

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Revision 0.3 (03-01-07)
8.2.18
Register
Address
62h
63h
/Write
Read
R/W
R/W
Note: The range numbers will be used to calculate the slope of the PWM ramp up. For the fractional
Register 62h, 63h: Min/Off, PWM Ramp Rate Control
These registers become read only when the Lock bit is set. Any further attempts to write to these
registers shall have no effect.
Description of OFFx bits:
The OFFx Bits [7:5] specify whether the duty cycle will be set to 0% or the Minimum Fan Duty Cycle
when the measured temperature falls below the Temperature LIMIT register setting. OFF1 applies to
PWM1, OFF2 applies to PWM2, and OFF3 applies to PWM3.
Description of Ramp Rate Control bits:
If the Remote1 or Remote2 pins are connected to a processor or chipset, instantaneous temperature
spikes may be sampled by the part. The auto fan control logic calculates the PWM duty cycle for all
temperature readings. If Ramp Rate Control is disabled, the PWM output will jump or oscillate
between different PWM duty cycles causing the fan to suddenly change speeds, which creates
unwanted fan noise. If enabled, the PWM Ramp Rate Control logic will prevent the PWM output from
jumping, instead the PWM will ramp up/down towards the new duty cycle at a pre-determined ramp
rate.
PWM 2, PWM 3 Ramp
Min/Off, PWM 1 Ramp
entries, the PWM will go on full when the temp reaches the next integer value e.g., for 3.33,
PWM will be full on at (min. temp + 4).
Table 8.32 PWM output below Limit depending on value of Off/Min
Register Name
Table 8.30 Register Setting vs. Temperature Range (continued)
Table 8.31 Register 62h, 63h: Min/Off, PWM Ramp Rate Control
Rate Control
Rate Control
OFF/MIN
RAN[3:0]
0
1
Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
1000
1001
1010
1011
1100
1101
0111
1110
1111
(MSb)
RR2E
OFF3
Bit 7
DATASHEET
At 0% duty below LIMIT
At Min PWM Duty below LIMIT
RR2-2
OFF2
Bit 6
70
RR2-1
RANGE ( ° C)
OFF1
Bit 5
PWM ACTION
13.33
26.67
53.33
10
16
20
32
40
80
RR2-0
Bit 4
RES
RR1E
RR3E
Bit 3
RR1-2
RR3-2
Bit 2
RR1-1
RR3-1
Bit 1
SMSC EMC6D103
RR1-0
RR3-0
(LSb)
Bit 0
Datasheet
Default
Value
00h
00h