ADM1026JST ON Semiconductor, ADM1026JST Datasheet - Page 38

• Manufacturer Part Number: ADM1026JST
• Description: IC CNTRL SYS REF/EEPROM 48LQFP
• Manufacturer: ON Semiconductor

Specifications of ADM1026JST

• Rohs Status: RoHS non-compliant
• Function: Hardware Monitor
• Topology: ADC, Comparator, Multiplexer, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: 0°C ~ 100°C, External Sensor
• Output Type: SMBus™
• Output Alarm: No
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: 0°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: 48-LFQFP

Table 12. Register 02h, Fans 0 to 3 Fan Divisor Register (Power−On Default 55h)
Table 13. Register 03h, Fans 4 to 7 Fan Divisor Register (Power−On Default 55h)
Table 14. Register 04h, DAC Configuration Register (Power−On Default FFh)
Table 15. Register 05h, PWM Control Register (Power−On Default FFh)
Table 16. Register 06h, EEPROM Register 1 (Power−On Default 00h)
1–0
3–2
5–4
7–6
1–0
3–2
5–4
7–6
7–0
7–4
3–0
7–0
Bit
Bit
Bit
Bit
Bit
PWM Control
DAC Control
Factory Use
Fan 0 Divisor
Fan 1 Divisor
Fan 2 Divisor
Fan 3 Divisor
Fan 4 Divisor
Fan 5 Divisor
Fan 6 Divisor
Fan 7 Divisor
Unused
Name
Name
Name
Name
Name
R/W
R/W
R/W
R/W
R/W
R/W
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
This register contains the value to which the fan speed DAC is programmed in
normal mode, or the 4 MSBs contain the minimum fan speed in auto fan speed
control mode.
This register contains the value to which the PWM fan speed is programmed in
normal mode, or the 4 MSBs contain the minimum fan speed in auto fan speed
control mode.
0000 = 0% Duty Cycle
0001 = 7% Duty Cycle
0101 = 33% Duty Cycle
0110 = 40% Duty Cycle
0111 = 47% Duty Cycle
1110 = 93% Duty Cycle
1111 = 100% Duty Cycle
Undefined
For factory use only. Do not write to this register.
Code
Sets the oscillator prescaler division ratio for Fan 0 speed measurement. The
division ratios, oscillator frequencies, and typical fan speeds (based on 2 tach
pulses per revolution) are as follows:
Same as Fan 0
Same as Fan 0
Same as Fan 0
Sets the oscillator prescaler division ratio for Fan 4 speed measurement. The
division ratios, oscillator frequencies, and typical fan speeds (based on 2 tach
pulses per revolution) are as follows:
Code
Same as Fan 4
Same as Fan 4
Same as Fan 4
00
01
10
11
00
01
10
11
http://onsemi.com
Divide
Divide By:
By:
1
2
4
8
38
1
2
4
8
Frequency (kHz)
Oscillator
11.25
22.5
5.62
2.81
Frequency (kHz)
Oscillator
11.25
22.5
5.62
2.81
Description
Description
Description
Description
Description
8800, nominal, for count of 153
4400, nominal, for count of 153
2200, nominal, for count of 153
1100, nominal, for count of 153
8800, nominal, for count of 153
4400, nominal, for count of 153
2200, nominal, for count of 153
1100, nominal, for count of 153
Fan Speed (RPM)
Fan Speed (RPM)