Fan Control Device with Hardware Monitoring and Acoustic Noise Reduction Features
Datasheet
Table 5.1 AVG[2:0] Bit Decoder
SFTR[7:5]
AVG1
MEASUREMENTS PER READING
REMOTE
DIODE 1
REMOTE
DIODE 2
INTERNAL
DIODE
ALL VOLTAGE READINGS
AVG2
AVG0
(+2.5V, +5V, +12V, VCCP, AND VCC)
0
0
0
1
0
0
1
X
0
1
128
16
128
16
8
1
8
1
X
X
16
16
16
32
16
32
32
32
Note: The default for the AVG[2:0] bits is ‘010’b.
To calculate conversion cycle timing for a given averaging mode:
■
■
■
Compute total number of temperature conversions (TEMP_CONV)
Compute total number of voltage conversions (VOLT_CONV)
Calculate Time to complete all conversions is:
Total Conversion Time = (TEMP_CONV)*96/(45kHz +/-10%)+ (VOLT_CONV)*68/(45kHz +/-10%)
Example: To calculate the nominal conversion time FOR AVG[2:0] = 001b.
Total Conversion Time = (TEMP_CONV)*96/(45kHz)+ (VOLT_CONV)*68/(45kHz)
Total Conversion Time = (16+16+1)*96/(45kHz)+ (5*1)*68/(45kHz)
Total Conversion Time = (33)*2.133ms+ (5)*1.511ms = ~78ms
Table 5.2 illustrates the min., nom., and max. conversion cycle timing for each of the four averaging
modes.
Table 5.2 Conversion Cycle Timing
CONVERSION CYCLE TIME (MSEC)
TOTAL
TOTAL
VOLTAGE
TEMPERATURE
CONVERSIONS
AVG[2:0]
CONVERSIONS
MIN.
NOM.
MAX.
000
001
(2x128)+(1x8)=264
(2x16)+(1x1)=33
3x16=48
5x8=40
5x1=5
567
71
624
78
693
87
01X (default)
1XX
5x16=80
5x32=160
203
406
223
447
248
496
3x32=96
Notes:
■
The hardware monitor conversion clock is 45KHz ± 10%.
■
Temperature conversions take 96 clocks, each (2.133ms nom.); Voltage conversions take 68
clocks, each (1.511ms nom).
5.3.1
Continuous Monitoring Mode
In the continuous monitoring mode, the sampling and conversion process is performed continuously
for each voltage and temperature reading after the Start bit is set high. The time for each voltage and
temperature reading is shown above for each measurement option.
SMSC EMC6D102
Revision 0.4 (04-05-05)
DATA1S9HEET
SMSC [ SMSC CORPORATION ]
