EMC2300-AZC-TR SMSC, EMC2300-AZC-TR Datasheet - Page 74

• Manufacturer Part Number: EMC2300-AZC-TR
• Description: Industrial Temperature Sensors Auto Fan Contrllr Up to 4 Fans
• Manufacturer: SMSC

Specifications of EMC2300-AZC-TR

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

Revision 0.32 (06-23-08)
BIT
BIT
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
PWM1_256/
PWM2_256/
PWM3_256/
PSYNC1
PSYNC2
PSYNC3
UPDT0
UPDT1
NAME
NAME
ROVR
GRD0
GRD1
SZEN
glitch
OPP
RES
RES
64
64
64
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
DEFAULT
DEFAULT
Table 8.55 PWM/TACH Test Register Bits
0
0
1
1
0
0
0
0
1
0
0
0
1
1
1
1
Table 8.54 PWM Option Register Bits
Determines the update rate of tachometer circuits associated with this
PWM driver.
Snap to Zero - determines if the PWM output ramps down to 00hor if is
immediately set to 00h when the input is set to 00h.
Sets the Guard time that the tachometer associated with this PWM driver
will wait after a transition from low to high before it begins measuring.
Opportunistic Mode enable - when set, enables opportunistic mode. The
tachometer reading is updated any time a valid tachometer reading can
be made. If a valid reading is detected prior to the update cycle, then the
update counter is reset.
Reserved
Reserved
is used to select the glitch suppression logic on the tachometer inputs
Determine how each PWM outputs exit SpinUp.
Determines the rollover value for mode 1 (all Tachs)
‘0’ 0080h - useful for simulation
‘1’ FFFFh
Scale the PWM duty cycle for the corresponding channel. When enabled,
will shift the PWM duty cycle down by 2 creating a duty cycle with a
resolution of 1/256. This allows the device to support higher PWM
frequencies
00 - once a second
01 - twice a second
1x - every 300msec.
‘0’ - Step down the PWM output to OFF at the programmed ramp rate.
‘1’ - Transition PWM output to OFF immediately when the duty cycle is
set to 00h.
00 = 63 clocks (90kHz clock ~ 700us)
01 = 32 clocks (90kHz clock ~356us)
10 = 16 clocks (90kHz clock ~178us)
11 = 8 clocks (90kHz clock ~89us)
‘0’ TACH inputs are synchronized to 90kHz oscillator.
‘1’ TACH inputs are deglitched and synchronized to 90kHz oscillator
‘0’ - Exit Spinup Asynchronously to the PWM duty cycle. The first PWM
period when SpinUP is terminate may be a partial period.
‘1’ - Exit Spinup at the beginning of the next PWM duty cycle period.
This option gets rid of the initial partial period created by exiting SpinUp,
but it extends the SpinUp time beyond the programmed limit.
‘0’= 64 count PWM duty cycle - resolution is 1/64
‘1’ = 256 count PWM duty cycle
DATASHEET
74
Fan Control Device with High Frequency PWM and Temperature Monitors
DESCRIPTION
DESCRIPTION
SMSC EMC2300
Datasheet