ADT7473ARQZ-1R7 ON Semiconductor, ADT7473ARQZ-1R7 Datasheet - Page 34

• Manufacturer Part Number: ADT7473ARQZ-1R7
• Description: IC THERM MON FAN CTLR 16-QSOP
• Manufacturer: ON Semiconductor
• Series: dBCool®r

Specifications of ADT7473ARQZ-1R7

• 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

Step 2: Configuring the Mux
the fans can be assigned to particular temperature channels.
Not only can fans be assigned to individual channels, but the
behavior of the fans is also configurable. For example, fans
can be run under automatic fan control, manually (under
software control), or at the fastest speed calculated by
multiple temperature channels. The mux is the bridge
between temperature measurement channels and the three
PWM outputs.
Register 0x5E (PWM configuration registers) control the
behavior of the fans connected to the PWM1, PWM2, and
PWM3 outputs. The values selected for these bits determine
how the mux connects a temperature measurement channel
to a PWM output.
Automatic Fan Control Mux Options
Bits [7:5] (BHVR), Register 0x5C, Register 0x5D, Register
0x5E.
After the system hardware configuration is determined,
Bits [7:5] (BHVR) of Register 0x5C, Register 0x5D, and
000 = Remote 1 temperature controls PWMx
001 = Local temperature controls PWMx
Figure 50. Assigning Temperature Channels to Fan Channels
http://onsemi.com
34
one PWM output based on multiple temperature channels.
The thermal characteristics of the three temperature zones
can be set to drive a single fan. An example is the fan turning
on when Remote 1 temperature exceeds 60°C, or if the local
temperature exceeds 45°C.
Other Mux Options
Bits [7:5] (BHVR), Register 0x5C, Register 0x5D, Register
0x5E.
this mode, PWM duty cycle registers (Register 0x30 to
Register 0x32) are writable and control the PWM outputs.
The fastest speed calculated options pertain to controlling
In normal mode, PWMx runs under software control. In
010 = Remote 2 temperature controls PWMx
101 = Fastest speed calculated by local and Remote 2
110 = Fastest speed calculated by all three
011 = PWMx runs full speed (default for
100 = PWMx disabled (default for ADT7473)
111 = manual mode
temperature controls PWMx
temperature channel controls PWMx
ADT7473−1)