EMC2103 Datasheet, PDF (62/85 Pages) SMSC Corporation – RPM-Based Fan Controller with HW Thermal Shutdown

RPM-Based Fan Controller with Hardware Thermal Shutdown
Datasheet
 ‘1’ - The Spin Up Routine will not drive the PWM to 100%. It will set the drive at the programmed
spin level for the entire duration of the programmed spin up time.
Bits 4 - 2 - SPIN_LVL[2:0] - Determines the final drive level that is used by the Spin Up Routine as
shown in Table 6.41.
Table 6.41 Spin Level
SPIN_LVL[2:0]
2
1
0
SPIN UP DRIVE LEVEL
0
0
0
30%
0
0
1
35%
0
1
0
40%
0
1
1
45%
1
0
0
50%
1
0
1
55%
1
1
0
60% (default)
1
1
1
65%
Bit 1 -0 - SPINUP_TIME[1:0] - determines the maximum Spin Time that the Spin Up Routine will run
for (see Section 5.7). If a valid tachometer measurement is not detected before the Spin Time has
elapsed, then an interrupt will be generated. When the RPM based Fan Speed Control Algorithm is
active, the fan driver will attempt to re-start the fan immediately after the end of the last spin up attempt.
The Spin Time is set as shown in Table 6.42.
Table 6.42 Spin Time
SPINUP_TIME[1:0]
1
0
0
0
0
1
1
0
1
1
The Fan Spin Up Configuration Register is software locked.
TOTAL SPIN UP TIME
250 ms
500 ms (default)
1 sec
2 sec
DS0005250A-page 62
 2013 Microchip Technology Inc.