ADT7461ARMZ-2 ON Semiconductor, ADT7461ARMZ-2 Datasheet - Page 11

• Manufacturer Part Number: ADT7461ARMZ-2
• Description: IC SENSOR TEMP DGTL 2CH 8MSOP
• Manufacturer: ON Semiconductor

Specifications of ADT7461ARMZ-2

• 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,
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

temperature limits are relevant. If Flag 6 and/or Flag 4 are
set, the THERM2 output goes low to indicate the
temperature measurements are outside the programmed
limits. Flag 5 and Flag 3 have no effect on THERM2. The
behavior of THERM2 is otherwise the same as THERM.
Offset Register
temperature measurement by clock noise or by the thermal
diode being located away from the hot spot. To achieve the
specified accuracy on this channel, these offsets must be
removed.
value in Registers 0x11 (high byte) and 0x12 (low byte, left
justified). Only the upper 2 bits of Register 0x12 are used.
The MSB of Register 0x11 is the sign bit. The minimum
offset that can be programmed is −128°C, and the maximum
is +127.75°C. The value in the offset register is added to the
measured value of the remote temperature.
and has no effect unless the user writes a different value to it.
Table 5. Status Register Bit Assignments
1. Polling of the BUSY bit is not recommended.
2. These flags stay high until the status register is read or they
When Pin 6 is configured as THERM2, only the high
Offset errors may be introduced into the remote
The offset value is stored as a 10-bit, twos complement
The offset register powers up with a default value of 0°C
Bit
7
6
5
4
3
2
1
0
are reset by POR.
(Note 1)
(Note 2)
(Note 2)
(Note 2)
(Note 2)
(Note 2)
RTHRM
LTHRM
RHIGH
LHIGH
RLOW
LLOW
OPEN
Name
BUSY
1 when ADC is converting
1 when local high temperature limit is
tripped
1 when local low temperature limit is
tripped
1 when remote high temperature limit is
tripped
1 when remote low temperature limit is
tripped
1 when remote sensor is an open circuit
1 when remote THERM limit is tripped
1 when local THERM limit is tripped
Function
http://onsemi.com
11
One-Shot Register
comparison cycle when the ADT7461 is in standby mode,
after which the device returns to standby. Writing to the
one-shot register address (0x0F) causes the ADT7461 to
perform a conversion and comparison on both the internal
and the external temperature channels. This is not a data
register as such; the write operation to Address 0x0F causes
the one-shot conversion. The data written to this address is
irrelevant and is not stored.
Consecutive ALERT Register
out-of-limit measurements must occur before an ALERT is
generated. The default value is that one out-of-limit
measurement generates an ALERT. The maximum value that
can be chosen is 4. The purpose of this register is to allow the
user to perform some filtering of the output. This is
particularly useful at the fastest three conversion rates, where
no averaging takes place. This register is at Address 0x22.
Table 6. Sample Offset Register Codes
Table 7. Consecutive ALERT Register Codes
NOTE:
The one-shot register is used to initiate a conversion and
The value written to this register determines how many
Register Value
Offset Value
+127.75°C
yxxx 000x
yxxx 001x
yxxx 011x
yxxx 111x
−0.25°C
+0.25°C
−128°C
−4°C
−1°C
+1°C
+4°C
0°C
x = don’t care bits, and y = SMBus timeout bit.
Default = 0. See SMBus section for more information.
1000 0000
0000 0000
0000 0000
0000 0001
0000 0100
1111 1100
0111 1111
1111 1111
1111 1111
0x11
Number of Out−of−Limit
Measurements Required
1
2
3
4
00 00 0000
00 00 0000
10 00 0000
00 00 0000
01 00 0000
00 00 0000
00 00 0000
11 00 0000
00 000000
0x12