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ADT7481ARMZ-R7

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20
© Semiconductor Components Industries, LLC, 2014
September, 2014 − Rev. 8
1 Publication Order Number:
ADT7481/D
ADT7481
Dual Channel Temperature
Sensor and Overtemperature
Alarm
The ADT7481 is a 3-channel digital thermometer and under/ over
temperature alarm, intended for use in PCs and thermal management
systems. It can measure its own ambient temperature or the
temperature of two remote thermal diodes. These thermal diodes can
be located in a CPU or GPU, or they can be discrete diode connected
transistors. The ambient temperature, or the temperature of the remote
thermal diode, can be accurately measured to ±1°C. The temperature
measurement range defaults to 0°C to +127°C, compatible with
ADM1032, but can be switched to a wider measurement range from
−64°C to +191°C.
The ADT7481 communicates over a 2-wire serial interface
compatible with System Management Bus (SMBus) standards. The
SMBus address of the ADT7481 is 0x4C. An ADT7481−1 with an
SMBus address of 0x4B is also available.
An ALERT
output signals when the on-chip or remote temperature
is outside the programmed limits. The THERM
output is a comparator
output that allows, for example, on/off control of a cooling fan. The
ALERT
output can be reconfigured as a second THERM output if
required.
Features
• 1 Local and 2 Remote Temperature Sensors
• 0.25°C Resolution/1°C Accuracy on Remote Channels
• 1°C Resolution/1°C Accuracy on Local Channel
• Extended, Switchable Temperature Measurement Range
0°C to 127°C (Default) or −64°C to +191°C
• 2-wire SMBus Serial Interface with SMBus ALERT Support
• Programmable Over/Undertemperature Limits
• Offset Registers for System Calibration
• Up to 2 Overtemperature Fail-Safe THERM Outputs
• Small 10-lead MSOP Package
• 240 mA Operating Current, 5 mA Standby Current
• These Devices are Pb-Free, Halogen Free and are RoHS Compliant
Applications
• Desktop and Notebook Computers
• Industrial Controllers
• Smart Batteries
• Automotive
• Embedded Systems
• Burn-In Applications
• Instrumentation
MARKING DIAGRAM
http://onsemi.com
See detailed ordering and shipping information in the package
dimensions section on page 19 of this data sheet.
ORDERING INFORMATION
MSOP−10
CASE 846AC
PIN ASSIGNMENT
T0x
AYWG
G
1
10
T0x = Refer to Ordering Info Table
A = Assembly Location
Y = Year
W = Work Week
G = Pb-Free Package
(Note: Microdot may be in either location)
ALERT/THERM2
SCLK
SDATA
D2+
D2−
V
DD
D1+
D1−
THERM
GND
10
9
8
7
6
5
4
3
2
1
ADT7481
ADT7481
http://onsemi.com
2
Figure 1. Functional Block Diagram
ON-CHIP
TEMPERATURE
SENSOR
ANALOG
MUX
BUSY
11-BIT A-TO-D
CONVERTER
LOCAL TEMPERATURE
VALUE REGISTER
REMOTE 1 AND 2 TEMP
OFFSET REGISTER
RUN/STANDBY
EXTERNAL DIODE OPEN-CIRCUIT
STATUS REGISTERS
SMBUS INTERFACE
LIMIT COMPARATOR
DIGITAL MUX
INTERRUPT
MASKING
SDATA SCLK
109
ONE-SHOT
REGISTER
CONVERSION RATE
REGISTER
LOCAL TEMPERATURE
THERM
LIMIT REGISTER
LOCAL TEMPERATURE
LOW LIMIT REGISTER
LOCAL TEMPERATURE
HIGH LIMIT REGISTER
REMOTE 1 & 2 TEMP.
THERM
LIMIT REG.
REMOTE 1 & 2 TEMP.
LOW LIMIT REGISTERS
REMOTE 1 & 2 TEMP.
HIGH LIMIT REGISTERS
CONFIGURATION
REGISTER
4
8
GND
5
V
DD
1
ADT7481
D1+
ALERT
/THERM2THERM
2
D1−
3
D2+
7
D2−
6
REMOTE 1 AND 2 TEMP
VALUE REGISTER
ADDRESS POINTER
REGISTER
Table 1. ABSOLUTE MAXIMUM RATINGS
Parameter Rating Unit
Positive Supply Voltage (V
DD
) to GND −0.3 to +3.6 V
D+ −0.3 to V
DD
+ 0.3 V
D− to GND −0.3 to +0.6 V
SCLK, SDATA, ALERT, THERM
−0.3 to +3.6
V
Input Current, SDATA, THERM −1 to +50 mA
Input Current, D− ±1 mA
ESD Rating, All Pins (Human Body Model) 1,500 V
Maximum Junction Temperature (T
J
MAX
) 150 °C
Storage Temperature Range −65 to +150 °C
IR Reflow Peak Temperature 220 °C
IR Reflow Peak Temperature for Pb-Free 260 °C
Lead Temperature, Soldering (10 sec) 300 °C
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
NOTE: This device is ESD sensitive. Use standard ESD precautions when handling.
Table 2. THERMAL CHARACTERISTICS
Package Type
q
JA
q
JC
Unit
10-lead MSOP 142 43.74 °C/W
ADT7481
http://onsemi.com
3
Table 3. PIN ASSIGNMENT
Pin No. Mnemonic Description
1 V
DD
Positive Supply, 3.0 V to 3.6 V.
2 D1+ Positive Connection to the Remote 1 Temperature Sensor.
3 D1− Negative Connection to the Remote 1 Temperature Sensor.
4 THERM Open-Drain Output. Requires pullup resistor. Signals overtemperature events, could be used to turn a
fan on/off, or throttle a CPU clock.
5 GND Supply Ground Connection.
6 D2− Negative Connection to the Remote 2 Temperature Sensor.
7 D2+ Positive Connection to the Remote 2 Temperature Sensor.
8 ALERT/THERM2 Open-Drain Logic Output. Used as interrupt or SMBALERT. This may also be configured as a second
THERM
output. Requires pullup resistor.
9 SDATA Logic Input/Output, SMBus Serial Data. Open-Drain Output. Requires pullup resistor.
10 SCLK Logic Input, SMBus Serial Clock. Requires pullup resistor.
Table 4. TIMING SPECIFICATIONS (Note 1)
Parameter Limit at T
MIN
and T
MAX
Unit Description
f
SCLK
400 kHz max
t
LOW
1.3
ms min
Clock low period, between 10% points.
t
HIGH
0.6
ms min
Clock high period, between 90% points.
t
R
300 ns max Clock/data rise time.
t
F
300 ns max Clock/data fall time.
t
SU;
STA
600 ns min Start condition setup time.
t
HD;
STA
(Note 2) 600 ns min Start condition hold time.
t
SU;
DAT
(Note 3) 100 ns min Data setup time.
t
HD;
DAT
300 ns min Data hold time.
t
SU;
STO
(Note 4) 600 ns min Stop condition setup time.
t
BUF
1.3
ms min
Bus free time between stop and start conditions.
1. Guaranteed by design, not production tested.
2. Time from 10% of SDATA to 90% of SCLK.
3. Time for 10% or 90% of SDATA to 10% of SCLK.
4. Time for 90% of SCLK to 10% of SDATA.
Figure 2. Serial Bus Timing
STOPSTART
t
SU; DAT
t
HIGH
t
F
t
HD; DAT
t
R
t
LOW
t
SU; STO
STOP START
SCLK
SDATA
t
BUF
t
HD; STA
t
HD; STA
t
SU; STA
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20

ADT7481ARMZ-R7

Mfr. #:
Buy ADT7481ARMZ-R7
Manufacturer:
ON Semiconductor
Description:
SENSOR DIGITAL 0C-127C 10MSOP
Lifecycle:
New from this manufacturer.
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