ADT7475ARQZ ON Semiconductor, ADT7475ARQZ Datasheet - Page 51

• Manufacturer Part Number: ADT7475ARQZ
• Description: IC REMOTE THERMAL CTRLR 16-QSOP
• Manufacturer: ON Semiconductor
• Series: dBCool®r

Specifications of ADT7475ARQZ

• Function: Fan Control, Temp Monitor
• Topology: ADC, Comparator, Fan Speed Counter, Multiplexer, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 125°C, External Sensor
• Output Type: SMBus™
• Output Alarm: No
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Full Temp Accuracy: +/- 0.5 C
• Digital Output - Bus Interface: Serial (3-Wire, 4-Wire)
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

1. This register becomes read−only when the Configuration Register 1 lock bit is set to 1. Any subsequent attempts to write to this register fail.
1. These registers become read−only when the ADT7475 is in automatic fan control mode.
Table 31. Register 0x63 — Enhanced Acoustics Register 2 (Power−On Default = 0x00)
Table 32. PWM Minimum Duty Cycle Registers
Bit No.
[2:0]
[6:4]
Register Address
[3]
[7]
0x64
0x65
0x66
Mnemonic
ACOU3
ACOU2
EN3
EN2
(Note 1)
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
When Bit 7 of Configuration Register 6 (0x10) is 0
Time Slot Increase
When Bit 7 of Configuration Register 6 (0x10) is 1
Time Slot Increase
When Bit 7 of Configuration Register 6 (0x10) is 0
Time Slot Increase
When Bit 7 of Configuration Register 6 (0x10) is 1
Time Slot Increase
Assuming that PWMx is associated with the local temperature channel, these bits define the
maximum rate of change of the PWMx output for local temperature related changes. Instead of
the fan speed jumping instantaneously to its newly determined speed, it ramps gracefully at the
rate determined by these bits. This feature ultimately enhances the acoustics of the fan.
000 = 1
001 = 2
010 = 3
011 = 4
100 = 8
101 = 12
110 = 24
111 = 48
000 = 1
001 = 2
010 = 3
011 = 4
100 = 8
101 = 12
110 = 24
111 = 48
When this bit is 1, smoothing is enabled on the Local temperature channel.
Assuming that PWMx is associated with the Remote 2 temperature channel, these bits define
the maximum rate of change of the PWMx output for Remote 2 temperature related changes.
Instead of the fan speed jumping instantaneously to its newly determined speed, it ramps
gracefully at the rate determined by these bits. This feature ultimately enhances the acoustics
of the fan.
000 = 1
001 = 2
010 = 3
011 = 4
100 = 8
101 = 12
110 = 24
111 = 48
000 = 1
001 = 2
010 = 3
011 = 4
100 = 8
101 = 12
110 = 24
111 = 48
When this bit is 1, smoothing is enabled on the Remote 2 temperature channel.
PWM1 minimum duty cycle.
PWM2 minimum duty cycle.
PWM3 minimum duty cycle.
(Note 1)
http://onsemi.com
Description
51
Time for 0% to 100%
Time for 0% to 100%
Time for 0% to 100%
Time for 0% to 100%
37.5 sec
18.8 sec
12.5 sec
7.5 sec
4.7 sec
3.1 sec
1.6 sec
0.8 sec
52.2 sec
26.1 sec
17.4 sec
10.4 sec
6.5 sec
4.4 sec
2.2 sec
1.1 sec
37.5 sec
18.8 sec
12.5 sec
7.5 sec
4.7 sec
3.1 sec
1.6 sec
0.8 sec
52.2 sec
26.1 sec
17.4 sec
10.4 sec
6.5 sec
4.4 sec
2.2 sec
1.1 sec
Description
0x80 (50% duty cycle)
0x80 (50% duty cycle)
0x80 (50% duty cycle)
Power−On Default