EMC2102-DZK SMSC, EMC2102-DZK Datasheet - Page 41

• Manufacturer Part Number: EMC2102-DZK
• Description: Industrial Temperature Sensors RPM Fan Contrllr
• Manufacturer: SMSC

Specifications of EMC2102-DZK

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

RPM-Based Fan Controller with HW Thermal Shutdown
Datasheet
SMSC EMC2102
6.13
52h
0
0
1
1
ADDRESS
1
EDGES[1:0]
The Fan Configuration Register controls the general operation of the RPM based Fan Control
Algorithm used for the High Side Fan Driver.
Bit 7 - EN - enables the RPM based Fan Control Algorithm.
Bit 6 - LIMIT2K - Adjusts the range of reported and programmed TACH count values.
Bit 4-3 - EDGES[1:0] - determines the minimum number of edges that must be detected on the TACH
signal to determine a single rotation. A typical fan measured 5 edges (for a 2-pole fan). For more
accurate TACH measurement, the minimum number of poles may be increased, however the TACH
measurement will be artificially higher than expected as denoted in the Effective TACH multiplier.
Additionally, some fans have more than 2-poles and therefore require more edges to be measured as
shown in the Number of Fan Poles
The EDGES[1:0] bits are shown in
Bit 2-0 - UPDATE - determines the base time between fan driver updates. The Update Time, along
with the Fan Step Register, is used to control the ramp rate of the drive response to provide a cleaner
transition of the actual fan operation as the desired fan speed changes. The Update Time is set as
shown in
Fan Configuration Register
FAN
Configuration
0
1
0
1
‘0’ - the control circuitry is disabled and the fan driver output is determined by the Fan Driver Setting
Register.
‘1’ (default) - the control circuitry is enabled and the Fan Driver output will be automatically updated
to maintain the programmed fan speed as indicated by the TACH Target Register.
‘0’ - the range of reported and programmable TACH values allows for a minimum speed of
approximately 500 RPM with reduced resolution to report lower speed values. The TACH Reading
count value is multiplied by a value of factor of ‘1x’.
‘1’ (default) - the range of reported and programmable TACH values allows for a minimum speed
of approximately 2000 RPM with increased resolution to report higher speed values. he TACH
Reading count value is multiplied by a value of factor of ‘4x’.
REGISTER
0
Table 6.19, "Update
Table 6.17 Fan Control Configuration Register
MINIMUM TACH
EN
Table 6.18 Minimum Edges for Fan Rotation
B7
EDGES
3
5
7
9
LIMIT2K
Time".
B6
DATASHEET
Table 6.18, "Minimum Edges for Fan
1 pole
2 poles (default)
3 poles
4 poles
-
NUMBER OF FAN POLES
B5
41
EDGES[1:0]
B4
B3
UPDATE[2:0]
B2
MULTIPLIER (BASED ON 2
Rotation".
B1
EFFECTIVE TACH
POLE FANS)
Revision 2.02 (05-17-07)
B0
0.5
1.5
2
2
CBh
DEFAULT