ADT7460ARQZ ON Semiconductor, ADT7460ARQZ Datasheet - Page 18

• 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

16−Bit Limits
TACH limits are also 16 bits, consisting of a high byte and
low byte. Since fans running under speed or stalled are
normally the only conditions of interest, only high limits
exist for fan TACHs. Since fan TACH period is actually
being measured, exceeding the limit indicates a slow or
stalled fan.
Out−of−Limit Comparisons
be enabled for monitoring. The ADT7460 measures all
parameters in round−robin format and sets the appropriate
status bit for out−of−limit conditions. Comparisons are done
differently depending on whether the measured value is
being compared to a high or low limit.
Table 19. Fan Limit Registers
The fan TACH measurements are 16−bit results. The fan
Once all limits have been programmed, the ADT7460 can
Register
0x54
0x55
0x56
0x57
0x58
0x59
0x5A
0x5B
High limit: > comparison performed
Low limit: < or = comparison performed
Figure 28. Temperature > Low Limit: No INT
TACH1 minimum high byte
TACH2 minimum high byte
TACH3 minimum high byte
TACH4 minimum high byte
TACH1 minimum low byte
TACH2 minimum low byte
TACH3 minimum low byte
TACH4 minimum low byte
Description
TEMP > LOW LIMIT
NO INT
LOW LIMIT
Default
0xFF
0xFF
0xFF
0xFF
0xFF
0xFF
0xFF
0xFF
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ADT7460
18
Figure 31. Temperature > High Limit: INT Occurs
Figure 29. Temperature = Low Limit: INT Occurs
Figure 30. Temperature = High Limit: No INT
NO INT
INT
HIGH LIMIT
TEMP > HIGH LIMIT
INT
LOW LIMIT
TEMP = LOW LIMIT
HIGH LIMIT
TEMP = HIGH LIMIT