EMC6D103-CZC-TR SMSC, EMC6D103-CZC-TR Datasheet - Page 45

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

Specifications of EMC6D103-CZC-TR

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

Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
Datasheet
SMSC EMC6D103
7.1.4.8
PWM STRETCHING PERIOD
Notes:
Note 7.1
Note 7.2
Examples of Minimum RPMs Supported
The following tables show minimum RPMs that can be supported with the different parameters. The
first table uses 3 edges and the second table uses 2 edges.
100ms
200ms
400ms
600ms
800ms
950ms
-Mode 1: If the programmed number of edges occurs before the counter reaches FFFFh latch the
tachometer count
-Mode 2: If the programmed number of edges occurs during the PWM ‘ON’ time or stretching time:
latch the tachometer count and stop stretching PWM (see Note below).
Whenever the programmed number of edges is detected, the edge detection ends and the state
machine is reset. The tachometer reading register is updated with the tachometer count value at
this time. See
In the case where the programmed number of edges occurs during the stretching time, the
tachometer value is latched when the last required edge is detected. The table below shows the
maximum values that may appear in the reading register.
50ms
Table 7.2 Max Tachometer Count Values for Different Stretch Periods
The maximum tachometer count does not take into account the guard time.
This max value will be FFFFh if the programmed number of edges is detected when the
count reaches FFFFh or if no edges are detected. If the count reaches FFFFh in Mode 1
or the Max stretch time in Mode 2 and some edges were detected, but less than the
programmed number of edges, the maximum tach count value is determined by the Slow
Interrupt Enable bit located in the TACHx Options registers at offsets 90h to 93h. If slow
interrupt detection is set to 0, the count will be forced to FFFEh, else the count will be
forced to FFFFh.
Note 7.2
below
Table 7.2
DATASHEET
MAXIMUM TACHOMETER COUNT AT END OF PERIOD
45
for the one exception to this behavior.
FFFFh
FFFFh
(Note
8CA0h
D2F0h
1194h
2328h
4650h
(Note
(Note
7.1)
7.2)
7.2)
Revision 0.3 (03-01-07)