ADT7473ARQZ-1R7 ON Semiconductor, ADT7473ARQZ-1R7 Datasheet - Page 65

• 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

Table 36. Register 0x62 — Enhanced Acoustics Register 1 (Power−On Default = 0x00)
1. This register becomes read−only when the Configuration Register 1 lock bit is set to 1. Any further attempts to write to this register have
Bit No.
[2:0]
[3]
[4]
[5]
[6]
[7]
no effect.
Mnemonic
ACOU
SYNC
MIN1
MIN2
MIN3
EN1
R/W (Note 1)
R/W
R/W
R/W
R/W
R/W
R/W
Time Slot Increase
000 = 1
001 = 2
010 = 3
011 = 4
100 = 8
101 = 12
110 = 24
111 = 48
These bits select the ramp rate applied to the PWM1 output. Instead of PWM1 jumping
instantaneously to its newly calculated speed, PWM1 ramps gradually at the rate determined
by these bits. This feature enhances the acoustics of the fan being driven by the PWM1
output.
When this bit is 1, acoustic enhancement is enabled on PWM1 output.
SYNC = 1 synchronizes fan speed measurements on TACH2, TACH3, and TACH4 to PWM3.
This allows up to three fans to be driven from PWM3 output and their speeds to be measured.
SYNC = 0 synchronizes only TACH3 and TACH4 to PWM3 output.
When the ADT7473/ADT7473−1 is in automatic fan control mode, this bit defines whether
PWM1 is off (0% duty cycle) or at PWM1 minimum duty cycle when the controlling
temperature is below its T
When the ADT7473/ADT7473−1 is in automatic fan speed control mode, this bit defines
whether PWM2 is off (0% duty cycle) or at PWM2 minimum duty cycle when the controlling
temperature is below its T
When the ADT7473/ADT7473−1 is in automatic fan speed control mode, this bit defines
whether PWM3 is off (0% duty cycle) or at PWM3 minimum duty cycle when the controlling
temperature is below its T
0 = 0% duty cycle below T
1 = PWM1 minimum duty cycle below T
0 = 0% duty cycle below T
1 = PWM 2 minimum duty cycle below T
0 = 0% duty cycle below T
1 = PWM3 minimum duty cycle below T
http://onsemi.com
Time for 33% to 100%
35 sec
17.6 sec
11.8 sec
7.0 sec
4.4 sec
3.0 sec
1.6 sec
0.8 sec
65
MIN
MIN
MIN
MIN
MIN
MIN
– hysteresis value.
− hysteresis value.
− hysteresis value.
− hysteresis.
− hysteresis.
− hysteresis.
Description
MIN
MIN
MIN
− hysteresis.
− hysteresis.
− hysteresis.