LM96000EVAL/NOPB National Semiconductor, LM96000EVAL/NOPB Datasheet - Page 21

• 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

Register
Address
5Ch
5Dh
5Eh
4.14 Registers 5C-5Eh: Fan Configuration
This register becomes Read Only when the Ready/Lock/Start/Override register Lock bit is set. Any further attempts to write to this
register shall have no effect. After power up the default value is used whenever the Ready/Lock/Start/Override register Start bit is
cleared even though modifications to this register are possible.
Bits [7:5] Zone/Mode
Bits [7:5] of the Fan Configuration registers associate each fan with a temperature sensor. When in Auto Fan Mode the fan will be
assigned to a zone, and its PWM duty cycle will be adjusted according to the temperature of that zone. If ‘Hottest’ option is selected
(101 or 110), the fan will be controlled by the hottest of zones 2 and 3, or of zones 1, 2, and 3. To determine the ‘Hottest’ zone the
PWM level for each zone is calculated then the the highest PWM value is selected. When in manual control mode, the Current
PWM duty registers (30h-32h) become Read/Write. It is then possible to control the PWM outputs with software by writing to these
registers. When the fan is disabled (100) the corresponding PWM output should be driven low (or high, if inverted).
Bit [4] PWM Invert
Bit [4] inverts the PWM output. If set to 0, 100% duty cycle will yield an output that is always high. If set to 1, 100% duty cycle will
yield an output that is always low.
Bit [3] Reserved
Bits [2:0] Spin Up
Bits [2:0] specify the ‘spin up’ time for the fan. When a fan is being started from a stationary state, the PWM output is held at 100%
duty cycle for the time specified in the table below before scaling to a lower speed.
Zone 1: External Diode 1 (processor)
Zone 2: Internal Sensor
Zone 3: External Diode 2
Read/
Write
R/W
R/W
R/W
Register
Name
Fan1 Configuration
Fan2 Configuration
Fan3 Configuration
ZON[2:0]
000
001
010
011
100
101
110
111
SPIN[2:0]
000
001
010
011
100
101
110
111
Bit 7
(MSB)
ZON2
ZON2
ZON2
TABLE 5. Fan Spin-Up Register
Fan Configuration
Fan on zone 1 auto
Fan on zone 2 auto
Fan on zone 3 auto
Fan always on full
Fan disabled
Fan controlled by hottest of zones 2, 3
Fan controlled by hottest of zones 1, 2, 3
Fan manually controlled (Test Mode)
TABLE 4. Fan Zone Setting
Bit 6
ZON1
ZON1
ZON1
Bit 5
ZON0
ZON0
ZON0
Spin Up Time
0 sec
100 ms
250 ms
400 ms
700 ms
1000 ms
2000 ms
4000 ms
21
Bit 4
INV
INV
INV
Bit 3
RES
RES
RES
Bit 2
SPIN2
SPIN2
SPIN2
Bit 1
SPIN1
SPIN1
SPIN1
Bit 0
(LSB)
SPIN0
SPIN0
SPIN0
Default
Value
62h
62h
62h
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