ADT7460ARQZ ON Semiconductor, ADT7460ARQZ Datasheet - Page 44

• Manufacturer Part Number: ADT7460ARQZ
• Description: IC REMOTE THRML/FAN CTRLR 16QSOP
• Manufacturer: ON Semiconductor
• Series: dBCool®r

Specifications of ADT7460ARQZ

• Function: Fan Control, Temp Monitor
• Topology: ADC, Comparator, Multiplexer, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 120°C, External Sensor
• Output Type: SMBus™
• Output Alarm: No
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 120°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Full Temp Accuracy: +/- 3 C
• Digital Output - Bus Interface: Serial (3-Wire)
• Maximum Operating Temperature: + 120 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. Further attempts to write to this register have no effect.
Table 73. Register 0x79 — THERM Status Register (Power−On Default = 0x00)
Table 74. Register 0x7A — THERM Limit Register (Power−On Default = 0x00)
Table 75. Register 0x7B — Fan Pulses per Revolution Register (Power−On Default = 0x55)
Table 76. Register 0x7D — Configuration Register 4 (Power−On Default = 0x00)
Bit No.
Bit No.
Bit No.
Bit No.
<7:1>
<7:0>
<1:0>
<3:2>
<5:4>
<7:6>
<3:2>
<7:4>
<0>
<0>
<1>
ASRT/TMR0
Mnemonic
Mnemonic
Mnemonic
Mnemonic
AL2.5V
FAN1
FAN2
FAN3
FAN4
LIMT
AINL
RES
RES
TMR
Read−only
Read−only
Read−only
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Sets maximum THERM assertion length allowed before an interrupt is generated. This is an
8−bit limit with a resolution of 22.76 ms allowing THERM assertion limits of 45.52 ms to 5.82 s
to be programmed. If the THERM assertion time exceeds this limit, Bit 5 (F4P) of Interrupt
Status Register 2 (Reg. 0x42) is set. If the limit value is 0x00, an interrupt is generated
immediately upon the assertion of the THERM input.
Sets number of pulses to be counted when measuring Fan1 speed. Can be used to determine
fan’s pulses per revolution for unknown fan type.
Pulses Counted00 = 1
01 = 2 (Default)
10 = 3
11 = 4
Sets number of pulses to be counted when measuring FAN2 speed. Can be used to determine
fan’s pulses per revolution for unknown fan type.
Pulses Counted00 = 1
01 = 2 (Default)
10 = 3
11 = 4
Sets number of pulses to be counted when measuring FAN3 speed. Can be used to determine
fan’s pulses per revolution for unknown fan type.
Pulses Counted00 = 1
01 = 2 (Default)
10 = 3
11 = 4
Sets number of pulses to be counted when measuring FAN4 speed. Can be used to determine
fan’s pulses per revolution for unknown fan type.
Pulses Counted00 = 1
01 = 2 (Default)
10 = 3
11 = 4
AL2.5V = 1, Pin 14 (2.5 V/SMBALERT) is configured as an SMBALERT interrupt output to
indicate out−of−limit error conditions.
AL2.5V = 0, Pin 14 (2.5 V/SMBALERT) is configured as a 2.5 V measurement input.
Reserved for future use.
These two bits define the input threshold for 2−wire fan speed measurements:
00 = ±20 mV
01 = ±40 mV
10 = ±80 mV
11 = ±130 mV
Reserved for future use.
Times how long THERM input is asserted. These seven bits read 0 until the THERM assertion
time exceeds 45.52 ms.
Is set high on the assertion of the THERM input. Cleared on read. If the THERM assertion
time exceeds 45.52 ms, this bit is set and becomes the LSB of the 8−bit TMR reading. This
allows THERM assertion times from 45.52 ms to 5.82 s to be reported back with a resolution
of 22.76 ms.
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ADT7460
44
Description
Description
Description
Description
(Note 1)