ADT7483AARQZ ON Semiconductor, ADT7483AARQZ Datasheet - Page 11

• Manufacturer Part Number: ADT7483AARQZ
• Description: IC THERM/ALARM 3-CHAN 16-QSOP
• Manufacturer: ON Semiconductor

Specifications of ADT7483AARQZ

• Function: Temp Monitoring System (Sensor)
• Topology: ADC, Comparator, Multiplexer, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 125°C, External Sensor
• Output Type: SMBus™
• Output Alarm: Yes
• 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: +/- 2.5 C
• Digital Output - Bus Interface: Serial (2-Wire)
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 7. Temperature Data Format (Local and Remote Temperature High Byte)
Temperature
–55°C
0°C
+1°C
+10°C
+25°C
+50°C
+75°C
+100°C
+125°C
+127°C
+150°C
1
2
3
The user may switch between measurement ranges at any time.
Switching the range also switches the data format. The next
temperature result following the switching is reported back to
the register in the new format. However, the contents of the
limit registers do not change. It is up to the user to ensure that
when the data format changes, the limit registers are
reprogrammed as necessary (for more information, see the
Limit Registers section).
REGISTERS
The registers in the ADT7483A are eight bits wide. These
registers are used to store the results of remote and local
temperature measurements, and high and low temperature
limits, and to configure and control the device. A description of
these registers is provided in this section.
Address Pointer Register
The address pointer register does not have, nor does it require,
an address because the first byte of every write operation is
automatically written to this register. The data in this first byte
always contains the address of another register on the ADT7483A,
which is stored in the address pointer register. It is to this other
register address that the second byte of a write operation is
written, or to which a subsequent read operation is performed.
The power-on default value of the address pointer register is
0x00, so if a read operation is performed immediately after
Offset binary scale temperature values are offset by +64.
Binary scale temperature measurement returns 0 for all temperatures <0°C.
Binary scale temperature measurement returns 127 for all temperatures >127°C.
Binary
0 000 0000
0 000 0000
0 000 0001
0 000 1010
0 001 1001
0 011 0010
0 100 1011
0 110 0100
0 111 1101
0 111 1111
0 111 1111
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2
3
power-on without first writing to the address pointer, the value
of the local temperature will be returned, since its register
address is 0x00.
Temperature Value Registers
The ADT7483A has five registers to store the results of local
and remote temperature measurements. These registers can
only be written to by the ADC and can be read by the user over
the SMBus.
•
•
•
•
•
•
The local temperature value register is at Address 0x00.
The Remote 1 temperature value high byte register is
at Address 0x01, with the Remote 1 low byte register at
Address 0x10.
The Remote 2 temperature value high byte register is
at Address 0x30, with the Remote 2 low byte register
at Address 0x33.
The Remote 2 temperature values can be read from
Address 0x01 for the high byte and Address 0x10 for
the low byte if Bit 3 of Configuration Register 1 is set to 1.
To read the Remote 1 temperature values, Bit 3 of
Configuration Register 1 should be set to 0.
The power-on default for all five registers is 0x00.
Offset Binary
0 000 1001
0 100 0000
0 100 0001
0 100 1010
0 101 1001
0 111 0010
1 000 1011
1 010 0100
1 011 1101
1 011 1111
1 101 0110
1
ADT7483A