ADT7473ARQZ-1R7 ON Semiconductor, ADT7473ARQZ-1R7 Datasheet - Page 13

• 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

output codes of the 10−bit ADC.
voltage input in 711 ms and averages 16 conversions to
reduce noise; a measurement takes nominally 11.38 ms.
Additional ADC Functions for Voltage Measurements
ADT7473/ADT7473−1 to offer the system designer
increased flexibility.
Turn−Off Averaging
16 readings have actually been made internally and the
results averaged before being placed into the value register.
When faster conversions are needed, setting Bit 4 of
Configuration Register 2 (0x73) turns averaging off. This
effectively gives a reading 16 times faster (711 ms), but the
reading may be noisier.
Bypass Voltage Input Attenuator
the attenuation circuitry from the V
the user to directly connect external sensors or to rescale the
analog voltage measurement inputs for other applications.
The input range of the ADC without the attenuators is 0 V
to 2.25 V.
Table 5 shows the input ranges of the analog inputs and
When the ADC is running, it samples and converts a
A number of other functions are available on the
For each voltage measurement read from a value register,
Setting Bit 5 of Configuration Register 2 (0x73) removes
CCP
input. This allows
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13
Single−Channel ADC Conversion
ADT7473/ADT7473−1
conversion mode. In this mode, the ADT7473/ADT7473−1
can be made to read a single voltage channel only. If the
internal ADT7473/ADT7473−1 clock is used, the selected
input is read every 711 ms. The appropriate ADC channel is
selected by writing to Bits [7:5] of the TACH1 minimum
high byte register (0x55).
Configuration Register 2 (0x73)
Bit 4 = 1; averaging off.
Bit 5 = 1; bypass input attenuators.
Bit 6 = 1; single−channel convert mode.
TACH1 Minimum High Byte Register (0x55)
Bits [7:5] select ADC channel for single−channel convert
mode.
Table 4. Programming Single−Channel ADC Mode
Setting Bit 6 of Configuration Register 2 (0x73) places the
Bits [7:5], Register 0x55
001
010
101
110
111
into
V
V
Remote 1 temperature
Local temperature
Remote 2 temperature
CCP
CC
single−channel
Channel Selected
ADC