LM96000EVAL/NOPB National Semiconductor, LM96000EVAL/NOPB Datasheet - Page 24

• Manufacturer Part Number: LM96000EVAL/NOPB
• Description: BOARD EVALUATION LM96000
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LM96000EVAL/NOPB

• Sensor Type: Temperature, Fan Controller
• Sensing Range: 0°C ~ 125°C
• Interface: SMBus (2-Wire/I²C)
• Sensitivity: ±1°C
• Voltage - Supply: 3 V ~ 3.6 V
• Embedded: No
• Utilized Ic / Part: LM96000
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM96000EVAL

www.national.com
ZN1E, ZN2E, and ZN3E enable temperature smoothing for zones 1, 2, and 3 respectively.
ZN1-2, ZN1-1, and ZN1-0 control smoothing time for Zone 1.
ZN2-2, ZN2-1, and ZN2-0 control smoothing time for Zone 2.
ZN3-2, ZN3-1, and ZN3-0 control smoothing time for Zone 3.
If the Remote1 or Remote2 pins are connected to a processor or chipset, instantaneous temperature spikes may be sampled by
the LM96000. If these spikes are not ignored, the CPU fan (if connected to LM96000) may turn on prematurely and produce
unpleasant noise. For this reason, any zone that is connected to a chipset or processor should have spike smoothing enabled.
When spike smoothing is enabled, the temperature reading registers will still reflect the current value of the temperature — not the
‘smoothed out’ value.
These registers become ready only when the Ready/Lock/Start/Override register Lock bit is set. Any further attempts to write to
these registers shall have no effect.
FIGURE 2. What LM96000 Auto Fan Control Sees With and Without Spike Smoothing
TABLE 8. PWM Output Below Limit Depending on Value of Off/Min
Off/Min
0
1
ZN-X[2:0]
000
001
010
011
100
101
110
111
PWM Action
At 0% duty below LIMIT
At Min PWM Duty below LIMIT
TABLE 7. Spike Smoothing
Spike Smoothed Over
35 seconds
17.6 seconds
11.8 seconds
7.0 seconds
4.4 seconds
3.0 seconds
1.6 seconds
.8 seconds
24
20084607