ANALOG DEVICES ADT7310 Service Manual
Digital SPI Temperature Sensor
ADT7310
Rev. A
ed by Analog Devices is believed to be accurate and reliable. However, no
Trademarks and registered trademarks are the property of their respective owners.
Fax: 781.461.3113 ©2009–2011 Analog Devices, Inc. All rights reserved.
INTERNAL
REFERENCE
8
7
TEMPERATURE
SENSOR
T
HIGH
T
CRIT
T
LOW
INTERNAL
OSCILLATOR
FILTER
LOGIC
Σ-Δ
MODULATOR
V
DD
GND
6
5
CT
INT
3
4
1
2
ADT7310
CS
SPI INT E RFACE
TEMPERATURE
VALUE
REGISTER
CONFIGURATION
AND STATUS
REGISTERS
T
LOW
REGISTER
T
CRIT
REGISTER
T
HYST
REGISTER
T
HIGH
REGISTER
SCLK
DOUT
DIN
07789-001
Data Sheet
FEATURES
High performance
Temperature accuracy
±0.5°C from −40°C to +105°C (2.7 V to 3.6 V)
±0.4°C from −40°C to +105°C (3.0 V)
16-bit temperature resolution: 0.0078°C
Fast first temperature conversion on power-up of 6 ms
Easy implementation
No temperature calibration/correction required by user
No linearity correction required
Low power
Power saving 1 sample per second (SPS) mode
700 µW typical at 3.3 V in normal mode
7 µW typical at 3.3 V in shutdown mode
Wide operating ranges
Temperature range: −55°C to +150°C
Voltage range: 2.7 V to 5.5 V
Programmable interrupts
Critical overtemperature interrupt
Overtemperature/undertemperature interrupt
SPI-compatible interface
8-lead narrow SOIC RoHS-compliant package
APPLICATIONS
Medical equipment
Environmental control systems
Computer thermal monitoring
±0.5°C Accurate, 16-Bit
Thermal protection
Industrial process control
Power system monitors
Hand-held applications
GENERAL DESCRIPTION
The ADT7310 is a high accuracy digital temperature sensor
in a narrow SOIC package. It contains a band gap temperature
reference and a 13-bit ADC to monitor and digitize the
temperature to a 0.0625°C resolution. The ADC resolution,
by default, is set to 13 bits (0.0625 °C). This can be changed
to 16 bits (0.0078 °C) by setting Bit 7 in the configuration
register (Register Address 0x01).
The ADT7310 is guaranteed to operate over supply voltages from
2.7 V to 5.5 V. Operating at 3.3 V, the average supply current is
typically 210 μA. The ADT7310 has a shutdown mode that
powers down the device and offers a shutdown current of
typically 2 μA. The ADT7310 is rated for operation over the
−55°C to +150°C temperature range.
The CT pin is an open-drain output that becomes active when
the temperature exceeds a programmable critical temperature
limit. The default critical temperature limit is 147°C. The INT
pin is also an open-drain output that becomes active when the
temperature exceeds a programmable limit. The INT and CT
pins can operate in either comparator or interrupt mode.
Information furnish
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
FUNCTIONAL BLOCK DIAGRAM
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Figure 1.
www.analog.com
ADT7310 Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
Status Register ............................................................................. 14
Applications ....................................................................................... 1
General Description ......................................................................... 1
Functional Block Diagram .............................................................. 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
SPI Timing Specifications ........................................................... 4
Absolute Maximum Ratings ............................................................ 5
ESD Caution .................................................................................. 5
Pin Configuration and Function Descriptions ............................. 6
Typical Performance Characteristics ............................................. 7
Theory of Operation ........................................................................ 9
Circuit Information ...................................................................... 9
Converter Details.......................................................................... 9
Temperature Measurement ......................................................... 9
One-Shot Mode .......................................................................... 10
Configuration Register .............................................................. 15
Temperature Value Register ...................................................... 16
ID Register................................................................................... 16
T
Setpoint Register ............................................................... 16
CRIT
T
Setpoint Register ............................................................... 17
HYST
T
Setpoint Register .............................................................. 17
HIGH
T
Setpoint Register ............................................................... 17
LOW
Serial Interface ................................................................................ 18
SPI Command Byte .................................................................... 18
Writing Data ............................................................................... 19
Reading Data ............................................................................... 20
Interfacing to DSPs or Microcontrollers ................................. 20
Serial Interface Reset .................................................................. 20
INT and CT Outputs ...................................................................... 21
Undertemperature and Overtemperature Detection ............ 21
1 SPS Mode .................................................................................. 10
Continuous Read Mode ............................................................. 12
Shutdown ..................................................................................... 12
Fault Queue ................................................................................. 12
Temperature Data Format ......................................................... 13
Temperature Conversion Formulas ......................................... 13
Registers ........................................................................................... 14
REVISION HISTORY
12/11—Rev. 0 to Rev. A
Changes to Features Section............................................................ 1
Changes to Table 1 ............................................................................ 3
Changes to Figure 6 and Figure 9 ................................................... 7
Changes to Figure 11 ........................................................................ 8
Changes to One-Shot Mode Section and 1 SPS Mode
Section .............................................................................................. 10
Changes to Shutdown Section and Figure 16 ............................. 12
Applications Information .............................................................. 23
Thermal Response Time ........................................................... 23
Supply Decoupling ..................................................................... 23
Temperature Monitoring ........................................................... 23
Outline Dimensions ....................................................................... 24
Ordering Guide .......................................................................... 24
Changes to Table 7 .......................................................................... 14
Changes to Table 8 .......................................................................... 15
Changes to Table 9 .......................................................................... 16
Changes to Table 12, Table 13, and Table 14 ............................... 17
Changes to Ordering Guide .......................................................... 24
4/09—Revision 0: Initial Version
Rev. A | Page 2 of 24
Data Sheet ADT7310
±0.5
°C
TA = −40°C to +105°C, VDD = 2.7 V to 3.6 V
±0.7
°C
TA = −55°C to +150°C, VDD = 2.7 V to 3.6 V
Twos complement temperature value of sign bit plus 12 ADC bits
Output High Voltage, VOH
0.7 × VDD
V
SPECIFICATIONS
TA = −55°C to +150°C; VDD = 2.7 V to 5.5 V; unless otherwise noted.
Table 1.
Parameter Min Typ Max Unit Test Conditions/Comments
TEMPERATURE SENSOR AND ADC
Accuracy1 −0.05 ±0.42 °C TA = −40°C to +105°C, VDD = 3.0 V
±0.44 °C TA = −40°C to +105°C, VDD = 2.7 V to 3.3 V
±0.5 °C TA = −55°C to +125°C, VDD = 3.0 V
±0.8 °C TA = −40°C to +105°C, VDD = 4.5 V to 5.5 V
±1.0 °C TA = −55°C to +150°C, VDD = 2.7 V to 5.5 V
ADC Resolution 13 Bits
16 Bits
Temperature Resolution
13-Bit 0.0625 °C 13-bit resolution (sign + 12-bit)
16-Bit 0.0078 °C 16-bit resolution (sign + 15-bit)
Temperature Conversion Time 240 ms Continuous conversion and one-shot conversion mode
Fast Temperature Conversion Time 6 ms First conversion on power-up only
1 SPS Conversion Time 60 ms Conversion time for 1 SPS mode
Temperature Hysteresis ±0.002 °C Temperature cycle = 25°C to 125°C, and back to 25°C
Repeatability3 ±0.015 °C TA = 25°C
DC PSRR 0.1 °C/V TA = 25°C
DIGITAL OUTPUTS (OPEN DRAIN)
High Output Leakage Current, IOH 0.1 5 µA CT and INT pins pulled up to 5.5 V
Output High Current 1 mA VOH = 5 .5V
Output Low Voltage, VOL 0.4 V IOL = 2 mA @ 5.5 V, IOL = 1 mA @ 3.3 V
(power-up default resolution)
Twos complement temperature value of sign bit plus 15 ADC bits
(Bit 7 = 1 in the configuration register)
Output Capacitance, C
OUT
3 pF
DIGITAL INPUTS
Input Current ±1 µA VIN = 0 V to VDD
Input Low Voltage, VIL 0.4 V
Input High Voltage, VIH 0.7 × VDD V
Pin Capacitance 5 10 pF
DIGITAL OUTPUT (DOUT)
Output High Voltage, VOH VOH − 0.3 V I
Output Low Voltage, V
Output Capacitance, C
OL
50 pF
OUT
0.4 V IOL = 200 µA
SOUR CE
= I
= 200 µA
SINK
POWER REQUIREMENTS
Supply Voltage 2.7 5.5 V
Supply Current
At 3.3 V 210 250 µA Peak current while converting, SPI interface inactive
At 5.5 V 250 300 µA Peak current while converting, SPI interface inactive
1 SPS Current
At 3.3V 46 µA VDD = 3.3 V, 1 SPS mode, TA = 25°C
At 5.5V 65 µA VDD = 5.5 V, 1 SPS mode, TA = 25°C
Shutdown Current
At 3.3 V 2.0 15 µA Supply current in shutdown mode
At 5.5 V 5.2 25 µA Supply current in shutdown mode
Power Dissipation Normal Mode 700 µW VDD = 3.3 V, normal mode at 25°C
Power Dissipation 1 SPS 150 µW Power dissipated for VDD = 3.3 V, TA = 25°C
1
Accuracy includes lifetime drift.
2
The equivalent 3 σ limits are ±0.33°C. This 3 σ specification is provided to enable comparison with other vendors who use these limits.
3
Based on a floating average of 10 readings.
Rev. A | Page 3 of 24
ADT7310 Data Sheet
SPI TIMING SPECIFICATIONS
TA = −55°C to +150°C, VDD = 2.7 V to 5.5 V, unless otherwise noted. All input signals are specified with rise time (tR) = fall time (tF) = 5 ns
(10% to 90% of V
) and timed from a voltage level of 1.6 V.
DD
Table 2.
Parameter
t1 0 ns min
1, 2
Limit at T
MIN
, T
(B Version) Unit Conditions/Comments
MAX
falling edge to SCLK active edge setup time3
CS
t2 100 ns min SCLK high pulse width
t3 100 ns min SCLK low pulse width
t4 30 ns min Data valid to SCLK edge setup time
t5 25 ns min Data valid to SCLK edge hold time
t6 0 ns min SCLK active edge to data valid delay3
60 ns max VDD = 4.5 V to 5.5 V
80 ns max VDD = 2.7 V to 3.6 V
4
t
10 ns min
7
Bus relinquish time after CS
inactive edge
80 ns max
t8 0 ns min
t9 0 ns min
rising edge to SCLK edge hold time
CS
falling edge to DOUT active time
CS
60 ns max VDD = 4.5 V to 5.5 V
80 ns max VDD = 2.7 V to 3.6 V
t10 10 ns min SCLK inactive edge to DOUT high
1
Sample tested during initial release to ensure compliance. All input signals are specified with tR = tF = 5 ns (10% to 90% of VDD) and timed from a voltage level of 1.6 V.
2
See Figure 2.
3
SCLK active edge is falling edge of SCLK.
4
This means that the times quoted in the timing characteristics are the true bus relinquish times of the part and, as such, are independent of external bus loading
capacitances.
CS
t
1
t
SCLK
DIN
DOUT
2
1
t
4
t
5
MSB LSB
t
9
t
3
23
7
8
12
t
6
MSB
t
8
7
8
t
10
t
7
LSB
07789-002
Figure 2. Detailed SPI Timing Diagram
I
(1.6mA WITH VDD = 5V,
SINK
100µA WITH V
TO
OUTPUT
PIN
10pF
I
SOURCE
100µA WITH V
Figure 3. Load Circuit for Timing Characterization
= 3V)
DD
1.6V
(200µA WIT H VDD=5V,
= 3V)
DD
07789-004
Rev. A | Page 4 of 24
Data Sheet ADT7310
Operating Temperature Range
–55°C to +150°C
Thermal Impedance3
Time at Peak Temperature
20 sec to 40 sec
TEMPERATURE (°C)
MAXIMUM POWER DISSIPATION (W)
1.2
0.8
1.0
0.6
0.2
0.4
0
–55
–50
–40
–30
–20
–10
0
102030405060708090
100
110
120
130
140
150
MAX PD = 3.4mW AT 150°C
07789-003
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter Rating
VDD to GND –0.3 V to +7 V
DIN Input Voltage to GND –0.3 V to VDD + 0.3 V
DOUT Voltage to GND –0.3 V to VDD + 0.3 V
SCLK Input Voltage to GND –0.3 V to VDD + 0.3 V
CS Input Voltage to GND –0.3 V to VDD + 0.3 V
CT and INT Output Voltage to GND –0.3 V to VDD + 0.3 V
ESD Rating (Human Body Model) 2.0 kV
Storage Temperature Range –65°C to +160°C
Maximum Junction Temperature, T
150°C
JMAX
8-Lead SOIC-N (R-8)
Power Dissipation1 W
MAX
= (T
JMAX
− T
2
A
θJA, Junction-to-Ambient (Still Air) 121°C/W
θJC, Junction-to-Case 56°C/W
IR Reflow Soldering 220°C
Peak Temperature (RoHS-
260°C (0°C)
Compliant Package)
)/θJA
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Ramp-Up Rate 3°C/sec maximum
Ramp-Down Rate –6°C/sec maximum
Time from 25°C to Peak Temperature 8 minutes maximum
1
Values relate to package being used on a standard 2-layer PCB. This gives a
worst-case θ
vs. ambient temperature (T
2
TA = ambient temperature.
3
Junction-to-case resistance is applicable to components featuring a
preferential flow direction, for example, components mounted on a heat
sink. Junction-to-ambient is more useful for air-cooled, PCB-mounted
components.
and θJC. See Figure 4 for a plot of maximum power dissipation
JA
).
A
Figure 4. SOIC_N Maximum Power Dissipation vs. Temperature
ESD CAUTION
Rev. A | Page 5 of 24
ADT7310 Data Sheet
SCLK
1
DOUT
2
DIN
3
CS
4
V
DD
8
GND
7
CT
6
INT
5
ADT7310
TOP VIEW
(Not to Scale)
07789-005
5
INT
Overtemperature and Undertemperature Indicator. Logic output. Power-up default setting is as an active low
8
VDD
Positive Supply Voltage (2.7 V to 5.5 V). The supply should be decoupled with a 0.1 µF ceramic capacitor to
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Figure 5. Pin Configuration
Table 4. Pin Function Descriptions
Pin No. Mnemonic Description
1 SCLK Serial Clock Input. The serial clock is used to clock in and clock out data to and from any register of the ADT7310.
2 DOUT Serial Data Output. Data is clocked out on the SCLK falling edge and is valid on the SCLK rising edge.
3 DIN Serial Data Input. Serial data to be loaded to the part’s control registers is provided on this input. Data is clocked
into the registers on the rising edge of SCLK.
4
CS
Chip Select Input. The device is selected when this input is low. The device is disabled when this pin is high.
comparator interrupt. Open-drain configuration. A pull-up resistor is required, typically 10 kΩ.
6 CT Critical Overtemperature Indicator. Logic output. Power-up default polarity is active low. Open-drain
configuration. A pull-up resistor is required, typically 10 kΩ.
7 GND Analog and Digital Ground.
ground.
Rev. A | Page 6 of 24
Data Sheet ADT7310
TEMPERATURE ERROR (°C)
1.0
07789-024
–1.0
–0.8
–0.6
–0.4
–0.2
0
0.2
0.4
0.6
0.8
1.0
–60 –40 –20 0 20 40 60 80 100 120 140 160
TEMPERATURE ERROR (°C)
TEMPERATURE (°C)
MAX ACCURACY LIM ITS
MAX ACCURACY LIM ITS
0
0.05
0.10
0.15
0.20
0.25
0.30
–100 –50 0 50 100 150 200
I
DD
(mA)
TEMPERA
TURE (°C)
3.0V 1SPS
5.5V 1SPS
5.5V CONTI NUOUS
CONVERSION
3.0V CONTI NUOUS
CONVERSION
07789-007
07789-025
3.6V
SHUTDOWN I
DD
(µA)
TEMPERATURE (°C)
0
5
10
15
20
25
30
–100 –50 0 50 100 150 200
3.3V
3.0V
2.7V
4.5V
5.0V
5.5V
TYPICAL PERFORMANCE CHARACTERISTICS
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
–60 –40 –20 0 20 40 60 80 100 120 140 160
MAX ACCURACY LIM ITS
MAX ACCURACY LIM ITS
TEMPERATURE (°C)
Figure 6. Temperature Accuracy at 3 V
07789-006
Figure 8. Operating Supply Current vs. Temperature
Figure 7. Temperature Accuracy at 5 V
Figure 9. Shutdown Current vs. Temperature
Rev. A | Page 7 of 24
ADT7310 Data Sheet
0
0.05
0.10
0.15
0.20
0.25
0.30
2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
I
DD
(mA)
SUPPLY VOLTAGE (V)
I
DD
CONTINUO US CONVERSION
I
DD
1SPS
07789-008
07789-009
0
1
2
3
4
5
6
7
8
2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
SHUTDOWN I
DD
(µA)
SUPPLY VOLTAGE (V)
0
20
40
60
80
100
120
140
160
0
403530252015105
TEMPERATURE (°C)
TIME (Seconds)
07789-011
Figure 10. Average Operating Supply Current vs. Supply Voltage at 25°C
Figure 11. Shutdown Current vs. Supply Voltage at 25°C
Figure 12. Response to Thermal Shock
Rev. A | Page 8 of 24
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