ANALOG DEVICES ADT7310 Service Manual
±0.5°C Accurate, 16-Bit Digital
www.BDTIC.com/ADI
SPI Temperature Sensor
Preliminary Technical Data
FEATURES
16-bit temperature-to-digital converter
Temperature accuracy ±0.5°C from 0°C to 70°C
SPI-compatible interface
Operating temperature from−55°C to +175°C
Operating voltage from 2.7 V to 5.5 V
Critical overtemperature indicator
Programmable overtemperature/undertemperature
interrupt
Shutdown mode for low power consumption
Power consumption: 1 mW typically at 3.3 V
8-lead narrow SOIC RoHS-compliant package
APPLICATIONS
Medical equipment
Isolated sensors
Environmental control systems
Computer thermal monitoring
Thermal protection
Industrial process control
Power system monitors
Hand-held applications
GENERAL DECSRIPTION
The ADT7310 is a high accuracy digital temperature sensor
in a standard narrow SOIC package. It contains a band gap
temperature sensor and a 13-bit ADC to monitor and digitize the
temperature to a resolution of 0.0625°C. The resolution can be
changed to 16 bits by setting a bit in the configuration register,
giving a 0.0078°C resolution. The default resolution is 13 bits.
The ADT7410 is guaranteed to operate at supply voltages from
2.7 V to 5.5 V. Operating at 3.3 V, the average supply current is
typically 250 A. The ADT7410 offers a shutdown mode that
powers down the device and gives a shutdown current of typically
0.8 A. The ADT7410 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 80°C. The INT
pin is also an open-drain output that becomes active when the
temperature exceeds a programmable limit. The INT pin can
operate in either comparator or interrupt mode.
FUNCTIONAL BLOCK DIAGRAM
INTERNAL
OSCILLATOR
Σ-Δ
MODULATOR
FILTER
LOGIC
T
CRIT
REGISTER
T
HYST
REGISTER
Figure 1.
T
LOW
REGISTER
T
HIGH
REGISTER
T
CRIT
T
HIGH
T
LOW
SCLK
DOUT
DIN
CS
INTERNAL
REFERENCE
1
TEMPERATURE
2
3
4
SPI INTERFACE
SENSOR
ADT7312
CONFIGURATIO N &
STATUS REGIST ERS
TEMPERAT URE
VALUE
REGISTER
PRODUCT HIGHLIGHTS
An on-chip temperature sensor allows an accurate
measurement of the ambient temperature. The measurable
temperature range is −55°C to +150°C.
Supply voltage is 2.7 V to 5.5 V.
Available in an 8-lead narrow SOIC packag
Temperature accuracy is ±0.5°C max from 0°C to 70°C.
Default temperature resolution is 0.0625°C.
First conversion on power-up is a fast conversion to
ensure fast CT and INT pin activation in overtemperature
situations.
Programmable temperature interrupt limits.
Shutdown mode reduces the current consumption to
0.8 A typical.
ADT7310
6
CT
5
INT
7
GND
8
V
DD
06791-001
Rev. PrA
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
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.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 www.analog.com
Fax: 781.461.3113 ©2008 Analog Devices, Inc. All rights reserved.
ADT7310 Preliminary Technical Data
www.BDTIC.com/ADI
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Decsription ......................................................................... 1
Product Highlights ........................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
SPI Timing Specifications ........................................................... 5
Absolute Maximum Ratings ............................................................ 6
ESD Caution .................................................................................. 6
Pin Configuration and Function Descriptions ............................. 7
Typical Performance Characteristics ............................................. 8
Theory of Operation ........................................................................ 9
Circuit Information ...................................................................... 9
Converter Details .......................................................................... 9
Temperature Measurement ......................................................... 9
One-Shot Mode .......................................................................... 10
Continuous Read Mode ............................................................. 11
Shutdown ..................................................................................... 11
Fault Queue ................................................................................. 11
Temperature Data Format ......................................................... 12
Registers ........................................................................................... 13
Serial Interface ................................................................................ 16
INT & CT Outputs ......................................................................... 18
INT Overtemperature Modes ................................................... 18
Application Information ................................................................ 20
Thermal Response Time ........................................................... 20
Supply Decoupling ..................................................................... 20
Temperature Monitoring ........................................................... 20
Outline Dimensions ....................................................................... 21
Ordering Guide .......................................................................... 21
REVISION HISTORY
11/07—Revision PrA: Preliminary Version A
Rev. PrA | Page 2 of 22
Preliminary Technical Data ADT7310
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SPECIFICATIONS
TA = −55°C to +150°C; VCC = 2.7 V to 5.5 V; unless otherwise noted
Table 1.
Parameter Min Typ Max Unit Test Conditions/Comments
TEMPERATURE SENSOR AND ADC
Accuracy ±0.5 °C TA = 0°C to +70°C
±0.5 °C TA = -20°C to +100°C, VDD = 3.3 V
±1.5 °C TA = −40°C to +125°C
±2 °C TA = −55°C to +150°C
ADC Resolution 13 Bits
16 Bits
Temperature Resolution
13 Bits 0.0625 °C
16 Bits 0.0078125 °C
Temperature Conversion Time 240 ms
Fast Temperature Conversion Time 6 10 ms First conversion on power-up only
Fast One-Shot Conversion Time 60 ms Fast one-shot conversion mode
Fast Temperature Conversion
Accuracy
±TBD ±TBD °C TA = −40°C to +125°C
±TBD ±TBD °C TA = −55°C to +150°C
Long-Term Drift 0.08 °C Drift over 10 years, if part is operated at 55°C
Temperature Hysteresis 0.02 °C Temperature cycle = 25°C to 125°C, and back to 25°C
Repeatability 0.01 ? °C TA = +25°C
DC PSRR TBD °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, I
Output Low Voltage, VOL 0.4 V IOL = 2 mA
Output High Voltage, VOH 0.7 × VDD V
Output Capacitance, C
RON Resistance (Low Output) 15 Ω Supply and temperature dependent
DIGITAL INPUTS
Input Current ±1 μA VIN = 0 V to VDD
Input Low Voltage, VIL 0.8 V
Input High Voltage, VIH 2.5 V
Pin Capacitance 10 pF
DIGITAL OUTPUT (DOUT)
Output High Voltage, VOH V
Output Low Voltage, V
Output Capacitance, C
POWER REQUIREMENTS
Supply Voltage 2.7 5.5 V
Supply Current at 3.3 V TBD TBD μA Peak current while converting ,SPI interface inactive
Supply Current at 5.0 V TBD 350 μA Peak current while converting ,SPI interface inactive
Shutdown Mode at 3.3 V TBD TBD μA Supply current in shutdown mode
Shutdown Mode at 5.0 V TBD 1 μA Supply current in shutdown mode
OH
OUT
OL
50 pF
OUT
±TBD ±TBD °C T
1 mA VOH = 5 V
3 10
− 0.3 V I
OH
0.4 V IOL = 200 μA
Twos complement temperature value of sign bit plus
12 ADC bits (power-up default resolution)
Twos complement temperature value of sign bit plus
15 ADC bits (D7 = 1 in the configuration register)
Continuous conversion mode and one-shot
conversion mode
= 0°C to +70°C
A
= I
SOURCE
= 200 μA
SINK
Rev. PrA | Page 3 of 22
ADT7310 Preliminary Technical Data
www.BDTIC.com/ADI
Parameter Min Typ Max Unit Test Conditions/Comments
Power Dissipation TBD μW VDD = 3.3 V, normal mode at 25°C
1 Sample Per Second 150 μW Power dissipated for VDD = 3.3 V at 25°C
1 Sample Per Second 315 μW Power dissipated for VDD = 5.0 V at 25°C
Rev. PrA | Page 4 of 22
Preliminary Technical Data ADT7310
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SPI TIMING SPECIFICATIONS
All input signals are specified with tR (rise time) = tF (fall time) = 5 ns (10% to 90% of VDD) and timed from a voltage level of 1.6 V.
T
= −55°C to +150°C, VDD = +2.7 V to +5.5 V, unless otherwise noted.
A
Table 2.
Parameter
t1 0 ns min
1, 2
Limit at T
, T
(B Version) Unit Conditions/Comments
MIN
MAX
falling edge to SCLK active edge setup time4
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
3
t
0 ns min SCLK active edge to data valid delay4
6
60 ns max VDD = 4.5 V to 5.5 V
80 ns max VDD = 2.7 V to 3.6 V
5
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
These numbers are measured with the load circuit shown in Figure 4 and defined as the time required for the output to cross the VOL or VOH limits.
4
SCLK active edge is falling edge of SCLK.
5
These numbers are derived from the measured time taken by the data output to change 0.5 V when loaded with the circuit shown in Figure 4. The measured number
is then extrapolated back to remove the effects of charging or discharging the 50 pF capacitor. 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
SCLK
DIN
DOUT
1
t
9
t
2
1
t
4
t
5
MSB LSB
t
3
23
Figure 2. Detailed SPI Timing Diagram
7
t
8
8
12
t
6
MSB
7
LSB
8
t
10
t
7
Rev. PrA | Page 5 of 22
ADT7310 Preliminary Technical Data
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ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter Rating
VDD to GND –0.3 V to +7 V
SDA Input Voltage to GND –0.3 V to VDD + 0.3 V
SDA Output Voltage to GND –0.3 V to VDD + 0.3 V
SCL 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
Operating Temperature Range –55°C to +150°C
Storage Temperature Range –65°C to +160°C
Maximum Junction Temperature, T
150.7°C
JMAX
8-Lead N-SOIC (R-8)
Power Dissipation1 W
MAX
= (T
JMAX
− T
2
A
)/θJA
Thermal Impedance3
θJA, Junction-to-Ambient (Still Air) 157°C/W
θJC, Junction-to-Case 56°C/W
IR Reflow Soldering
Peak Temperature (RoHS-Compliant
260°C (+0°C)
Package)
Time at Peak Temperature 20 sec to 40 sec
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 θJA and θJC. Refer to Figure 3 for a plot of maximum power
dissipation vs. ambient temperature (TA).
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.
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.
ESD CAUTION
I
(1.6mA WITH VDD = 5V,
SINK
100µA WIT H V
DD
Figure 3. SOIC_N Maximum Power Dissipation vs. Temperature
= 3V)
TO
OUTPUT
PIN
50pF
I
SOURCE
100µA WIT H V
Figure 4. Load Circuit for Timing Characterization
Rev. PrA | Page 6 of 22
1.6V
(200µA WIT H VDD = 5V,
= 3V)
DD
6791-002
Preliminary Technical Data ADT7310
D
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PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
SCLK
1
ADT7310
2
DOUT
DIN
TOPVIEW
(Not to Sca l e )
3
4
CS
Figure 5. Pin Configuration
8
V
DD
7
GN
6
CT
5
INT
Table 4. Pin Function Descriptions
Pin
Mnemonic Description
No.
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
3 DIN
SPI Serial Data Output. Data from the registers output from the part on DOUT pin . Data is clocked
out on the SCLK falling edge and is valid on the SCLK rising edge.
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. Logic Input. The device is selected when this input is low. The SCLK input is
disabled when this pin is high.
5 INT
Over temperature and Under temperature Indicator. Power-up default setting is as an active low
comparator interrupt. Open-drain configuration. Needs a pull-up resistor.
6 CT
Critical Over temperature Indicator. Power-up default polarity is active low. Open-drain
configuration. Needs a pull-up resistor.
7 GND Analog and Digital Ground.
8 VDD Positive Supply Voltage, 2.7 V to 5.5 V. The supply should be decoupled to ground.
Rev. PrA | Page 7 of 22
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