ADT7461ARMZ-002 ON Semiconductor, ADT7461ARMZ-002 Datasheet - Page 9

• Manufacturer Part Number: ADT7461ARMZ-002
• Description: IC TEMP MONITOR +/-1C DUAL 8MSOP
• Manufacturer: ON Semiconductor

Specifications of ADT7461ARMZ-002

• 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 ~ 5.5 V
• Operating Temperature: -40°C ~ 120°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Full Temp Accuracy: +/- 1 C, +/- 3 C
• Digital Output - Bus Interface: Serial (2-Wire)
• Maximum Operating Temperature: + 127 C
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

time. Switching the range also switches the data format. The
next temperature result following the switching is reported
contents of the limit registers are not changed. The user must
ensure that the limit registers are reprogrammed, as
necessary, when the data format changes. See the Limit
Registers section for more
ADT7461 Registers
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 follows. Additional details are provided in
Table 3 to Table 7.
Address Pointer Register
address, as 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
ADT7461, which is stored in the address pointer register.
This register address is written to by the second byte of a
write operation or is used for a subsequent read operation.
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, since its register address is 0x00.
Temperature Value Registers
local and remote temperature measurements. These
registers can only be written to by the ADC and can be read
Table 2. Temperature Data Format (Local and Remote
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
back to the register in the new format. However, the
The ADT7461 contains a total of 22 8-bit registers. These
The address pointer register does not have or require an
The power-on default value of the address pointer register
The ADT7461 has three registers to store the results of
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
information.
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
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. Bits 0, 1, 3,
and 4 are reserved and should not be written to by the user.
ALERT 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 only applies if Pin 6 is configured as
ALERT. If Pin 6 is configured as THERM2, the value of
Bit 7 has no effect.
operating mode with the 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, so values can be read from or written to the
ADT7461 via the SMBus in this mode. 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.
ADT7461. 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), the temperature measurement range is set
between 0°C to +127°C. Setting Bit 2 to 1 means that the
measurement range is set to the extended temperature range.
Conversion Rate Register
Address 0x0A at write. The lowest four bits of this register
are used to program the conversion rate by dividing the
Table 3. Configuration Register Bit Assignments
4, 3
1, 0
Bit
The external temperature value high byte register is at
The configuration register is Address 0x03 at read and
Bit 7 of the configuration register is used to mask the
If Bit 6 is set to 0 (the power-on default), the device is in
Bit 5 determines the configuration of Pin 6 on the
Bit 2 sets the temperature measurement range. If Bit 2 is
The conversion rate register is Address 0x04 at read and
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