EMC2305-1-AP-TR SMSC, EMC2305-1-AP-TR Datasheet - Page 39

• Manufacturer Part Number: EMC2305-1-AP-TR
• Description: Industrial Temperature Sensors Penta RPM-Based PWN Fan Speed Controller
• Manufacturer: SMSC

Specifications of EMC2305-1-AP-TR

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

ADDR
63h
73h
Multiple RPM-Based PWM Fan Controller for Five Fans
Datasheet
SMSC EMC2305
R/W
R/W
R/W
Configuration 2
Configuration 2
REGISTER
The Fan Configuration 2 registers control the tachometer measurement and advanced features of the
RPM-based Fan Speed Control Algorithm.
Bit 6 - EN_RRCx - Enables ramp rate control when the corresponding fan driver is operated in the
Direct Setting Mode.
Bit 5 - GLITCH_ENx - Disables the low pass glitch filter that removes high frequency noise injected
on the TACHx pin.
Bits 4 - 3 - DER_OPTx[1:0] - Control some of the advanced options that affect the derivative portion
of the RPM-based Fan Speed Control Algorithm as shown in
Bit 2 - 1 - ERR_RNGx[1:0] - Control some of the advanced options that affect the error window. When
the measured fan speed is within the programmed error window around the target speed, then the fan
drive setting is not updated. The algorithm will continue to monitor the fan speed and calculate
necessary drive setting changes based on the error; however, these changes are ignored.
1
0
0
1
1
Fan 4
Fan 5
‘0’ (default) - Ramp rate control is disabled. When the fan driver is operating in Direct Setting mode,
the fan setting will instantly transition to the next programmed setting.
‘1’ - Ramp rate control is enabled. When the fan driver is operating in Direct Setting mode, the fan
drive setting will follow the ramp rate controls as determined by the Fan Step and Update Time
settings. The maximum fan drive setting step is capped at the Fan Step setting and is updated
based on the Update Time as given by
‘0’ - The glitch filter is disabled.
‘1’ (default) - The glitch filter is enabled.
DER_OPTX[1:0]
Table 5.14 Fan Configuration 2 Registers (continued)
B7
-
-
RRC4
RRC5
EN_
EN_
Table 5.15 Derivative Options
B6
0
0
1
0
1
DATASHEET
GLITCH_
GLITCH_
EN4
EN5
B5
39
Table
5.13.
DER_OPT4 [1:0]
DER_OPT5 [1:0]
are used effectively causing the derivative term to
Basic derivative. The derivative of the error from
to the iterative Fan Drive Register setting and is
Both the basic derivative and the step derivative
the current drive setting and the target is added
the current drive setting and the target is added
Step derivative. The derivative of the error from
B4
have double the effect of the derivative term.
to the iterative Fan Drive Register setting (in
addition to proportional and integral terms)
not capped by the Fan Step Register.
Table
No derivative options used
B3
5.15.
OPERATION
(default)
ERR_RNG4[1:0]
ERR_RN55[1:0]
B2
Revision 1.2 (03-22-10)
B1
B0
-
-
DEFAULT
28h
28h