ADT7461AARMZ-2REEL ON Semiconductor, ADT7461AARMZ-2REEL Datasheet - Page 9

• Manufacturer Part Number: ADT7461AARMZ-2REEL
• Description: IC SENSOR TEMP DGTL 2CH 8-MSOP
• Manufacturer: ON Semiconductor

Specifications of ADT7461AARMZ-2REEL

• Function: Temp Monitoring System (Sensor)
• Topology: ADC, Comparator, Multiplexer, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: 0°C ~ 127°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: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

time. Switching the range likewise 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. More information
on this is found in the Limit Registers section.
ADT7461A Registers
These registers store the results of remote and local
temperature measurements, high and low temperature
limits, and configure and control the device. See the Address
Pointer Register section through the Consecutive ALERT
Register section of this data sheet for more information on
the ADT7461A registers. Additional details are shown in
Table 4 through Table 8. The entire register map is available
in Table 9.
Address Pointer Register
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 ADT7461A that is stored in the address
pointer register. It is to this register address that the second
byte of a write operation is written, or to which a subsequent
read operation is performed.
is 0x00. Therefore, if a read operation is performed
immediately after power−on, without first writing to the
address pointer, the value of the local temperature is returned
because its register address is 0x00.
Table 3. Temperature Data Format
(Temperature High Byte)
1. Offset binary scale temperature values are offset by 64°C.
2. Binary scale temperature measurement returns 0°C for all
3. Binary scale temperature measurement returns 127°C for all
Temperature
The user can switch between measurement ranges at any
The ADT7461A contains 22, 8−bit registers in total.
The address pointer register itself does not have, nor does
The power−on default value of the address pointer register
temperatures < 0°C.
temperatures > 127°C.
+100°C
+125°C
+127°C
+150°C
+10°C
+25°C
+50°C
+75°C
–55°C
+1°C
0°C
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
(Note 2)
(Note 3)
Binary
Offset Binary (Note 1)
0 000 1001
0 100 0000
0 100 0001
0 100 1010
0 101 1001
1 000 1011
1 010 0100
1 101 0110
0 111 0010
1 011 1101
1 011 1111
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9
Temperature Value Registers
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.
Address 0x01, with the low byte register at Address 0x10.
The power−on default for all three registers is 0x00.
Configuration Register
Address 0x09 at write. Its power−on default is 0x00. Only
four bits of the configuration register are used. Bit 0, Bit 1,
Bit 3, and Bit 4 are reserved; the user does not write to them.
output. If Bit 7 is 0, the ALERT output is enabled. This is the
power−on default. If Bit 7 is set to 1, the ALERT output is
disabled. This applies only if Pin 6 is configured as ALERT.
If Pin 6 is configured as THERM2, then the value of Bit 7
has no effect.
is in operating mode with ADC converting. If Bit 6 is set to
1, the device is in standby mode and the ADC does not
convert. The SMBus does, however, remain active in
standby mode; therefore, values can be read from or written
to the ADT7461A via the SMBus. The ALERT and THERM
outputs are also active in standby mode. Changes made to
the registers in standby mode that affect the THERM or
ALERT outputs cause these signals to be updated.
ADT7461A. If Bit 5 is 0 (default), then Pin 6 is configured
as an ALERT output. If Bit 5 is 1, then Pin 6 is configured
as a THERM2 output. Bit 7, the ALERT mask bit, is only
active when Pin 6 is configured as an ALERT output. If Pin
6 is set up as a THERM2 output, then Bit 7 has no effect.
0 (default value), the temperature measurement range is set
between 0°C to +127°C. Setting Bit 2 to 1 sets the
measurement range to the extended temperature range
(−64°C to +191°C).
Table 4. Configuration Register Bit Assignments
4, 3
1, 0
Bit
The ADT7461A has three registers to store the results of
The external temperature value high byte register is at
The configuration register is Address 0x03 at read and
Bit 7 of the configuration register masks the ALERT
If Bit 6 is set to 0, which is power−on default, the device
Bit 5 determines the configuration of Pin 6 on the
Bit 2 sets the temperature measurement range. If Bit 2 is
7
6
5
2
MASK1
RUN/STOP
ALERT/
THERM2
Reserved
Temperature
Range Select
Reserved
Name
0 = ALERT Enabled
1 = ALERT Masked
0 = Run
1 = Standby
0 = ALERT
1 = THERM2
0 = 0°C to 127°C
1 = Extended range
Function
Power−On
Default
0
0
0
0
0
0