Automotive, ±0.5°C Accurate, 16-Bit Digital SPI Temperature Sensor ADT7311 Data Sheet

Automotive, ±0.5°C Accurate, 16-Bit Digital SPI Temperature Sensor ADT7311 Data Sheet
Automotive, ±0.5°C Accurate, 16-Bit
Digital SPI Temperature Sensor
ADT7311
Data Sheet
FEATURES
GENERAL DESCRIPTION
Qualified for automotive applications
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 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: −40°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
The ADT7311 is a high accuracy digital temperature sensor
in a narrow 8-lead SOIC package. It contains a band gap
temperature reference and a 16-bit ADC to monitor and digitize
the temperature to a 0.0078°C resolution. The ADC resolution,
by default, is set to 13 bits (0.0625°C). The ADC resolution is a
user programmable mode that can be changed through the
serial interface.
APPLICATIONS
1.
2.
3.
4.
The ADT7311 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 ADT7311 has a shutdown mode that
powers down the device and offers a shutdown current of
typically 2 μA. The ADT7311 is rated for operation over the
−40°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.
PRODUCT HIGHLIGHTS
Battery management
Climate control and infotainment
Lighting
Powertrain
Thermocouple cold junction compensation
GPS
Ease of use, no calibration or correction required by the user.
Low power consumption.
Excellent long-term stability and reliability.
Packaged in an 8-lead SOIC, RoHS-compliant package.
FUNCTIONAL BLOCK DIAGRAM
ADT7311
SPI INTERFACE
DOUT 2
DIN 3
CS 4
INTERNAL
REFERENCE
INTERNAL
OSCILLATOR
6
CT
5
INT
7
GND
8
VDD
TCRIT
TEMPERATURE
VALUE
REGISTER
CONFIGURATION,
STATUS, AND
ID REGISTERS
THYST
REGISTER
TCRIT
REGISTER
THIGH
REGISTER
TLOW
REGISTER
TEMPERATURE
SENSOR
Σ-∆
MODULATOR
THIGH
FILTER
LOGIC
TLOW
09050-001
SCLK 1
Figure 1.
Rev. 0
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rights of third parties that may result from its use. Specifications subject to change without notice. No
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Fax: 781.461.3113
©2011 Analog Devices, Inc. All rights reserved.
ADT7311
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1 Configuration Register .............................................................. 14 Applications....................................................................................... 1 Temperature Value Register ...................................................... 15 General Description ......................................................................... 1 ID Register................................................................................... 15 Product Highlights ........................................................................... 1 TCRIT Setpoint Register ............................................................... 15 Functional Block Diagram .............................................................. 1 THYST Setpoint Register............................................................... 16 Revision History ............................................................................... 2 THIGH Setpoint Register .............................................................. 16 Specifications..................................................................................... 3 TLOW Setpoint Register ............................................................... 16 SPI Timing Specifications ........................................................... 4 Serial Peripheral Interface ............................................................. 17 Absolute Maximum Ratings............................................................ 5 SPI Command Byte.................................................................... 17 ESD Caution.................................................................................. 5 Writing Data ............................................................................... 18 Pin Configuration and Function Descriptions............................. 6 Reading Data............................................................................... 19 Typical Performance Characteristics ............................................. 7 Interfacing to DSPs or Microcontrollers ................................. 19 Theory of Operation ........................................................................ 9 Serial Interface Reset.................................................................. 19 Circuit Information...................................................................... 9 INT and CT Outputs...................................................................... 20 Converter Details.......................................................................... 9 Undertemperature and Overtemperature Detection ............ 20 Temperature Measurement ......................................................... 9 Applications Information .............................................................. 22 One-Shot Mode .......................................................................... 10 Thermal Response Time ........................................................... 22 1 SPS Mode.................................................................................. 10 Supply Decoupling ..................................................................... 22 Shutdown..................................................................................... 11 Powering from a Switching Regulator..................................... 22 Fault Queue ................................................................................. 11 Temperature Monitoring........................................................... 22 Temperature Data Format ......................................................... 12 Quick Guide to Measuring Temperature ................................ 22 Temperature Conversion Formulas ......................................... 12 Outline Dimensions ....................................................................... 23 Registers ........................................................................................... 13 Ordering Guide .......................................................................... 23 Status Register ............................................................................. 13 Automotive Products ................................................................. 23 REVISION HISTORY
9/11—Revision 0: Initial Version
Rev. 0 | Page 2 of 24
Data Sheet
ADT7311
SPECIFICATIONS
TA = −40°C to +150°C; VDD = 2.7 V to 5.5 V; unless otherwise noted.
Table 1.
Parameter
TEMPERATURE SENSOR AND ADC
Accuracy 1
Min
ADC Resolution
Temperature Resolution
13-Bit
16-Bit
Temperature Conversion Time
Fast Temperature Conversion Time
1 SPS Conversion Time
Temperature Hysteresis
Repeatability
DC PSRR
DIGITAL OUTPUTS (CT, INT), OPEN
DRAIN
High Output Leakage Current, IOH
Output Low Voltage, VOL
Output High Voltage, VOH
Output Capacitance, COUT
DIGITAL INPUTS (DIN, SCLK, CS)
Input Current
Input Low Voltage, VIL
Input High Voltage, VIH
Pin Capacitance
DIGITAL OUTPUT (DOUT)
Output High Voltage, VOH
Output Low Voltage, VOL
Output Capacitance, COUT
POWER REQUIREMENTS
Supply Voltage
Supply Current
At 3.3 V
At 5.5 V
1 SPS Current
At 3.3 V
At 5.5 V
Typ
Max
Unit
Test Conditions/Comments
−0.05
±0.4
±0.44
±0.5
±0.5
±0.7
±0.8
±1.0
13
°C
°C
°C
°C
°C
°C
°C
Bits
16
Bits
TA = −40°C to +105°C, VDD = 3.0 V
TA = −40°C to +105°C, VDD = 2.7 V to 3.3 V
TA = −40°C to +125°C, VDD = 3.0 V
TA = −40°C to +105°C, VDD = 2.7 V to 3.6 V
TA = −40°C to +150°C, VDD = 2.7 V to 3.6 V
TA = −40°C to +105°C, VDD = 4.5 V to 5.5 V
TA = −40°C to +150°C, VDD = 2.7 V to 5.5 V
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 (Bit 7 = 1 in the configuration register)
0.0625
0.0078
240
6
60
±0.002
±0.015
0.1
°C
°C
ms
ms
ms
°C
°C
°C/V
13-bit resolution (sign + 12 bits)
16-bit resolution (sign + 15 bits)
Continuous conversion and one-shot conversion mode
First conversion on power-up only
Conversion time for 1 SPS mode
Temperature cycle = 25°C to 125°C and back to 25°C
TA = 25°C
TA = 25°C
μA
V
V
CT and INT pins pulled up to 5.5 V
IOL = 2 mA at 5.5 V, IOL = 1 mA at 3.3 V
0.1
5
0.4
0.7 ×
VDD
2
pF
±1
0.4
μA
V
V
10
pF
0.7 ×
VDD
5
V
ISOURCE = ISINK = 200 μA
0.4
50
V
pF
IOL = 200 μA
5.5
V
265
300
μA
μA
Peak current while converting, SPI interface inactive
Peak current while converting, SPI interface inactive
μA
μA
VDD = 3.3 V, 1 SPS mode, TA = 25°C
VDD = 5.5 V, 1 SPS mode, TA = 25°C
VOH −
0.3
2.7
210
250
46
65
VIN = 0 V to VDD
Rev. 0 | Page 3 of 24
ADT7311
Data Sheet
Parameter
Shutdown Current
At 3.3 V
At 5.5 V
Power Dissipation Normal Mode
Power Dissipation 1 SPS
1
Min
Typ
Max
Unit
Test Conditions/Comments
2.0
5.2
700
150
15
25
μA
μA
μW
μW
Supply current in shutdown mode
Supply current in shutdown mode
VDD = 3.3 V, normal mode at 25°C
Power dissipated for VDD = 3.3 V, TA = 25°C
Accuracy includes lifetime drift.
SPI TIMING SPECIFICATIONS
TA = −40°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 VDD) and timed from a voltage level of 1.6 V.
Table 2.
Parameter1, 2
Limit at TMIN, TMAX
Unit
Conditions/Comments
t1
t2
t3
t4
t5
t6
0
100
100
30
25
5
60
80
10
80
0
0
60
80
10
ns min
ns min
ns min
ns min
ns min
ns min
ns max
ns max
ns min
ns max
ns min
ns min
ns max
ns max
ns min
CS falling edge to SCLK active edge setup time
SCLK high pulse width
SCLK low pulse width
Data setup time prior to SCLK rising edge
Data hold time after SCLK rising edge
Data access time after SCLK falling edge
VDD = 4.5 V to 5.5 V
VDD = 2.7 V to 3.6 V
Bus relinquish time after CS inactive edge
t73
t8
t9
t10
SCLK inactive edge to CS rising edge hold time
CS falling edge to DOUT active time
VDD = 4.5 V to 5.5 V
VDD = 2.7 V to 3.6 V
SCLK inactive edge to DOUT low
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.
See Figure 2.
3
This means that the times quoted in the timing characteristics in Table 2 are the true bus relinquish times of the part and, as such, are independent of external bus
loading capacitances.
2
CS
t1
t2
1
SCLK
t8
t3
2
3
6
7
8
9
10
23
24
t4
t5
LSB
t6
t9
DOUT
MSB
t10
LSB
t7
Figure 2. Detailed SPI Timing Diagram
Rev. 0 | Page 4 of 24
09050-002
MSB
DIN
Data Sheet
ADT7311
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter
VDD to GND
DIN Input Voltage to GND
DOUT Voltage to GND
SCLK Input Voltage to GND
CS Input Voltage to GND
CT and INT Output Voltage to GND
ESD Rating (Human Body Model)
Operating Temperature Range1
Storage Temperature Range
Maximum Junction Temperature, TJMAX
8-Lead SOIC_N (R-8)
Power Dissipation2
Thermal Impedance4
θJA, Junction-to-Ambient (Still Air)
θJC, Junction-to-Case
IR Reflow Soldering
Peak Temperature (RoHS-Compliant
Package)
Time at Peak Temperature
Ramp-Up Rate
Ramp-Down Rate
Time from 25°C to Peak Temperature
Rating
−0.3 V to +7 V
−0.3 V to VDD + 0.3 V
−0.3 V to VDD + 0.3 V
−0.3 V to VDD + 0.3 V
−0.3 V to VDD + 0.3 V
−0.3 V to VDD + 0.3 V
2.0 kV
−40°C to +150°C
−65°C to +160°C
150°C
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
WMAX = (TJMAX − TA3)/θJA
121°C/W
56°C/W
220°C
260°C (0°C)
20 sec to 40 sec
3°C/sec maximum
−6°C/sec maximum
8 minutes maximum
1
Operating at extended temperatures over prolonged periods depends on
the lifetime performance of the part. Consult your local Analog Devices, Inc.,
account representative for more details.
2
Value relates to package being used on a standard 2-layer PCB. This gives a
worst-case θJA and θJC.
3
TA = ambient temperature.
4
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.
Rev. 0 | Page 5 of 24
ADT7311
Data Sheet
SCLK 1
DOUT 2
DIN 3
ADT7311
TOP VIEW
CS 4 (Not to Scale)
8
VDD
7
GND
6
CT
5
INT
09050-005
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Figure 3. Pin Configuration
Table 4. Pin Function Descriptions
Pin No.
1
2
3
Mnemonic
SCLK
DOUT
DIN
4
5
CS
INT
6
CT
7
8
GND
VDD
Description
Serial Clock Input. The serial clock is used to clock in and clock out data to and from any register of the ADT7311.
Serial Data Output. 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.
Chip Select Input. The device is selected when this input is low. The device is disabled when this pin is high.
Overtemperature and Undertemperature Indicator. Logic output. The power-up default setting is as an active
low comparator interrupt. Open-drain configuration. A pull-up resistor is required, typically 10 kΩ.
Critical Overtemperature Indicator. Logic output. Power-up default polarity is active low. Open-drain
configuration. A pull-up resistor is required, typically 10 kΩ.
Analog and Digital Ground.
Positive Supply Voltage (2.7 V to 5.5 V). The supply should be decoupled with a 0.1 μF ceramic capacitor to GND.
Rev. 0 | Page 6 of 24
Data Sheet
ADT7311
TYPICAL PERFORMANCE CHARACTERISTICS
300
1.0
5.5V CONTINUOUS
CONVERSION
0.6
250
MAX ACCURACY LIMITS
0.4
3.0V CONTINUOUS
CONVERSION
200
0.2
IDD (µA)
0
150
–0.2
100
–0.4
5.5V 1SPS
–0.6
MAX ACCURACY LIMITS
50
–40
–20
0
20
40
60
80
100
120
140
160
TEMPERATURE (°C)
0
–100
09050-006
–1.0
–60
0
50
100
150
200
200
TEMPERATURE (°C)
Figure 4. Temperature Accuracy at 3 V
Figure 6. Operating Supply Current vs. Temperature
8
1.0
0.8
7
MAX ACCURACY LIMITS
0.6
6
0.4
5.5V
5
IDD (µA)
0.2
0
–0.2
5.0V
4
4.5V
3
–0.4
3.6V
2
–0.6
MAX ACCURACY LIMITS
–0.8
–1.0
–60
–40
–20
0
20
40
60
80
3.0V
2.7V
1
100
120
TEMPERATURE (°C)
140
160
09050-024
TEMPERATURE ERROR (°C)
–50
09050-007
3.0V 1SPS
–0.8
09050-025
TEMPERATURE ERROR (°C)
0.8
0
–100
–50
0
50
100
150
TEMPERATURE (°C)
Figure 7. Shutdown Current vs. Temperature
Figure 5. Temperature Accuracy at 5 V
Rev. 0 | Page 7 of 24
ADT7311
Data Sheet
300
160
140
IDD CONTINUOUS CONVERSION
250
TEMPERATURE (°C)
120
150
100
60
3.0
3.5
4.0
4.5
5.0
5.5
6.0
SUPPLY VOLTAGE (V)
09050-008
20
0
2.5
Figure 8. Average Operating Supply Current vs. Supply Voltage at 25°C
8
7
6
5
4
3
2
1
0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
SUPPLY VOLTAGE (V)
6.0
09050-009
SHUTDOWN IDD (µA)
80
40
IDD 1SPS
50
100
Figure 9. Shutdown Current vs. Supply Voltage at 25°C
Rev. 0 | Page 8 of 24
0
0
5
10
15
20
25
30
TIME (Seconds)
Figure 10. Response to Thermal Shock
35
40
09050-011
IDD (µA)
200
Data Sheet
ADT7311
THEORY OF OPERATION
CIRCUIT INFORMATION
Σ-∆ MODULATOR
The ADT7311 is a high accuracy digital temperature sensor that
uses a 16-bit ADC to monitor and digitize the temperature to
0.0078°C of resolution. The ADC resolution, by default, is set to
13 bits (0.0625°C). An internal temperature sensor generates a
voltage proportional to absolute temperature, which is compared to an internal voltage reference and input into a precision
digital modulator.
INTEGRATOR
COMPARATOR
VOLTAGE REF
AND VPTAT
1-BIT
DAC
CLOCK
GENERATOR
LPF DIGITAL
FILTER
13-BIT/
16-BIT
TEMPERATURE
VALUE
REGISTER
09050-012
1-BIT
The internal temperature sensor has high accuracy and linearity
over the entire rated temperature range without needing correction or calibration by the user.
Figure 11. Σ-∆ Modulator
The sensor output is digitized by a sigma-delta (Σ-Δ) modulator,
also known as the charge balance type analog-to-digital converter. This type of converter utilizes time-domain oversampling
and a high accuracy comparator to deliver 16 bits of resolution
in an extremely compact circuit.
CONVERTER DETAILS
The Σ-Δ modulator consists of an input sampler, a summing
network, an integrator, a comparator, and a 1-bit DAC. This
architecture creates a negative feedback loop and minimizes the
integrator output by changing the duty cycle of the comparator
output in response to input voltage changes. The comparator
samples the output of the integrator at a much higher rate than
the input sampling frequency. This oversampling spreads the
quantization noise over a much wider band than that of the
input signal, improving overall noise performance and
increasing accuracy.
The modulated output of the comparator is encoded using a
circuit technique that results in SPI temperature data.
TEMPERATURE MEASUREMENT
In normal mode (default power-up mode), the ADT7311 runs
an automatic conversion sequence. During this automatic
conversion sequence, a conversion typically takes 240 ms to
complete and the ADT7311 is continuously converting. This
means that as soon as one temperature conversion is completed,
another temperature conversion begins. Each temperature
conversion result is stored in the temperature value register and
is available through the SPI interface. In continuous conversion
mode, the read operation provides the most recent converted
result.
On power-up, the first conversion is a fast conversion, taking
typically 6 ms. If the temperature exceeds 147°C, the CT pin
asserts low. If the temperature exceeds 64°C, the INT pin asserts
low. Fast conversion temperature accuracy is typically within ±5°C.
The conversion clock for the part is generated internally.
No external clock is required except when reading from and
writing to the serial port.
The measured temperature value is compared with a critical
temperature limit (stored in the 16-bit TCRIT setpoint read/write
register), a high temperature limit (stored in the 16-bit THIGH
setpoint read/write register), and a low temperature limit (stored
in the 16-bit TLOW setpoint read/write register). If the measured
value exceeds these limits, the INT pin is activated; and if it
exceeds the TCRIT limit, the CT pin is activated. The INT and CT
pins are programmable for polarity via the configuration register,
and the INT and CT pins are also programmable for interrupt
mode via the configuration register.
Rev. 0 | Page 9 of 24
ADT7311
Data Sheet
CS
0x08
DIN
0x20
WAIT 240ms MINIMUM
FOR CONVERSION TO FINISH
DATA
09050-026
DOUT
SCLK
Figure 12. Typical SPI One-Shot Write to Configuration Register Followed by a Read from the Temperature Value Register
ONE-SHOT MODE
1 SPS MODE
Setting Bit 6 to 0 and Bit 5 to 1 of the configuration register
(Register Address 0x01) enables the one-shot mode. When
this mode is enabled, the ADT7311 immediately completes a
conversion and then goes into shutdown mode.
In this mode, the part performs one measurement per second.
A conversion takes only 60 ms, and it remains in the idle state
for the remaining 940 ms period. This mode is enabled by
writing 1 to Bit 6 and 0 to Bit 5 of the configuration register
(Register Address 0x01).
Wait for a minimum of 240 ms after writing to the operation
mode bits before reading back the temperature from the
temperature value register. This time ensures that the ADT7311
has time to power up and complete a conversion.
To obtain an updated temperature conversion, reset the Bit 6 to
0 and Bit 5 to 1 in the configuration register (0x01).
The one-shot mode is useful when one of the circuit design
priorities is to reduce power consumption.
Rev. 0 | Page 10 of 24
Data Sheet
ADT7311
CT and INT Operation in One-Shot Mode
See Figure 13 for more information on one-shot CT pin
operation for TCRIT overtemperature events when one of the
limits is exceeded. Note that, in interrupt mode, a read from
any register resets the INT and CT pins.
For the INT pin in comparator mode, if the temperature drops
below the THIGH – THYST value or goes above the TLOW + THYST
value, a write to the operation mode bits (Bit 5 and Bit 6 of
the configuration register, Register Address 0x01) resets the
INT pin.
For the CT pin in comparator mode, if the temperature
drops below the TCRIT – THYST value, a write to the operation
mode bits (Bit 5 and Bit 6 of the configuration register,
Register Address 0x01) resets the CT pin (see Figure 13).
When using one-shot mode, ensure that the refresh rate is
appropriate to the application being used.
SHUTDOWN
The ADT7311 can be placed in shutdown mode by writing 1
to Bit 6 and 1 to Bit 5 of the configuration register (Register
Address 0x01). The ADT7311 can be taken out of shutdown
mode by writing 0 to Bit 6 and 0 to Bit 5 of the configuration
register (Register Address 0x01). The ADT7311 typically takes
1 ms (with a 0.1 μF decoupling capacitor) to come out of shutdown mode. The conversion result from the last conversion
prior to shutdown can still be read from the ADT7311 even
when it is in shutdown mode. When the part is taken out of
shutdown mode, the internal clock is started and a conversion
is initiated.
FAULT QUEUE
Bit 0 and Bit 1 of the configuration register (Register Address
0x01) are used to set up a fault queue. Up to four faults are
provided to prevent false tripping of the INT and CT pins when
the ADT7311 is used in a noisy temperature environment. The
number of faults set in the queue must occur consecutively to
set the INT and CT outputs. For example, if the number of
faults set in the queue is four, then four consecutive temperature
conversions must occur, with each result exceeding a temperature limit in any of the limit registers, before the INT and CT
pins are activated. If two consecutive temperature conversions
exceed a temperature limit and the third conversion does not,
the fault count is reset to 0.
TEMPERATURE
149°C
148°C
TCRIT
147°C
146°C
145°C
144°C
143°C
TCRIT – THYST
142°C
141°C
140°C
CT PIN
POLARITY = ACTIVE LOW
CT PIN
POLARITY = ACTIVE HIGH
TIME
WRITE TO
BIT 5 AND BIT 6 OF
CONFIGURATION
REGISTER.*
WRITE TO
BIT 5 AND BIT 6 OF
CONFIGURATION
REGISTER.*
*THERE IS A 240ms DELAY BETWEEN WRITING TO THE CONFIGURATION REGISTER TO START
A STANDARD ONE-SHOT CONVERSION AND THE CT PIN GOING ACTIVE. THIS IS DUE TO THE
CONVERSION TIME. THE DELAY IS 60ms IN THE CASE OF A ONE-SHOT CONVERSION.
Figure 13. One-Shot CT Pin
Rev. 0 | Page 11 of 24
09050-013
WRITE TO
BIT 5 AND BIT 6 OF
CONFIGURATION
REGISTER.*
ADT7311
Data Sheet
TEMPERATURE DATA FORMAT
TEMPERATURE CONVERSION FORMULAS
One LSB of the ADC corresponds to 0.0625°C in 13-bit mode.
The ADC can theoretically measure a temperature range of
255°C, but the ADT7311 is guaranteed to measure a low value
temperature limit of −40°C to a high value temperature limit
of +150°C. The temperature measurement result is stored in
the 16-bit temperature value register and is compared with the
high temperature limits stored in the TCRIT setpoint register and
the THIGH setpoint register. It is also compared with the low
temperature limit stored in the TLOW setpoint register.
16-Bit Temperature Data Format
Temperature data in the temperature value register, the TCRIT
setpoint register, the THIGH setpoint register, and the TLOW
setpoint register is represented by a 13-bit twos complement
word. The MSB is the temperature sign bit. The three LSBs,
Bit 0 to Bit 2, on power-up, are not part of the temperature
conversion result and are flag bits for TCRIT, THIGH, and TLOW.
Table 5 shows the 13-bit temperature data format without
Bit 0 to Bit 2.
Positive Temperature = ADC Code(dec)/128
Negative Temperature = (ADC Code(dec) – 65,536)/128
where ADC Code uses all 16 bits of the data byte, including the
sign bit.
Negative Temperature = (ADC Code(dec) – 32,768)/128
where the MSB is removed from the ADC code.
13-Bit Temperature Data Format
Positive Temperature = ADC Code(dec)/16
Negative Temperature = (ADC Code(dec) − 8192)/16
where ADC Code uses all 13 bits of the data byte, including the
sign bit.
Negative Temperature = (ADC Code(dec) – 4096)/16
The number of bits in the temperature data-word can be
extended to 16 bits, twos complement, by setting Bit 7 to 1
in the configuration register (Register Address 0x01). When
using a 16-bit temperature data value, Bit 0 to Bit 2 are not
used as flag bits and are instead the LSB bits of the temperature
value. The power-on default setting has a 13-bit temperature
data value.
Reading back the temperature from the temperature value register
requires a 2-byte read. Designers that use a 9-bit temperature
data format can still use the ADT7311 by ignoring the last four
LSBs of the 13-bit temperature value. These four LSBs are Bit 3
to Bit 6 in Table 5.
where the MSB is removed from the ADC code.
10-Bit Temperature Data Format
Positive Temperature = ADC Code(dec)/2
Negative Temperature = (ADC Code(dec) – 1024)/2
where ADC Code uses all 10 bits of the data byte, including the
sign bit.
Negative Temperature = (ADC Code(dec) – 512)/2
where the MSB is removed from the ADC code.
9-Bit Temperature Data Format
Positive Temperature = ADC Code(dec)
Table 5. 13-Bit Temperature Data Format
Temperature
−40°C
−25°C
−0.0625°C
0°C
+0.0625°C
+25°C
+50°C
+125°C
+150°C
Digital Output
(Binary) Bits[15:3]
1 1100 1110 0000
1 1110 0111 0000
1 1111 1111 1111
0 0000 0000 0000
0 0000 0000 0001
0 0001 1001 0000
0 0011 0010 0000
0 0111 1101 0000
0 1001 0110 0000
Negative Temperature = ADC Code(dec) – 512
Digital
Output (Hex)
0x1CE0
0x1E70
0x1FFF
0x000
0x001
0x190
0x320
0x7D0
0x960
where ADC Code uses all nine bits of the data byte, including
the sign bit.
Negative Temperature = ADC Code(dec) – 256
where the MSB is removed from the ADC code.
Rev. 0 | Page 12 of 24
Data Sheet
ADT7311
REGISTERS
STATUS REGISTER
The ADT7311 contains eight registers:
•
•
•
•
This 8-bit read-only register (Register Address 0x00) reflects the
status of the overtemperature and undertemperature interrupts
that can cause the CT and INT pins to go active. It also reflects the
status of a temperature conversion operation. The interrupt flags
in this register are reset by a read operation to the status register
and/or when the temperature value returns within the temperature limits including hysteresis. The RDY bit is reset after a read
from the temperature value register. In one-shot and 1 SPS modes,
the RDY bit is reset after a write to the operation mode bits.
A status register
A configuration register
Five temperature registers
An ID register
The status register, temperature value register, and the ID
register are read-only.
Table 6. ADT7311 Registers
Register
Address
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
Power-On
Default
0x80
0x00
0x0000
0xC3
0x4980 (147°C)
0x05 (5°C)
0x2000 (64°C)
0x0500 (10°C)
Description
Status
Configuration
Temperature value
ID
TCRIT setpoint
THYST setpoint
THIGH setpoint
TLOW setpoint
Table 7. Status Register (Register Address 0x00)
Bit
[3:0]
4
Default
Value
0000
0
Type
R
R
Name
Unused
TLOW
5
0
R
THIGH
6
0
R
TCRIT
7
1
R
RDY
Description
Reads back 0.
This bit is set to 1 when the temperature goes below the TLOW temperature limit. The bit clears to 0
when the status register is read and/or when the temperature measured goes back above the limit
set in the TLOW + THYST setpoint registers.
This bit is set to 1 when the temperature rises above the THIGH temperature limit. The bit clears to 0
when the status register is read and/or when the temperature measured drops below the limit set
in the THIGH − THYST setpoint registers.
This bit is set to 1 when the temperature rises above the TCRIT temperature limit. This bit clears to 0
when the status register is read and/or when the temperature measured drops below the limit set
in the TCRIT − THYST setpoint registers.
This bit goes low when the temperature conversion result is written into the temperature value
register. It is reset to 1 when the temperature value register is read. In one-shot and 1 SPS modes,
this bit is reset after a write to the operation mode bits.
Rev. 0 | Page 13 of 24
ADT7311
Data Sheet
CONFIGURATION REGISTER
This 8-bit read/write register (Register Address 0x01) stores various
configuration modes for the ADT7311, including shutdown,
overtemperature and undertemperature interrupts, one-shot,
continuous conversion, interrupt pins polarity, and
overtemperature fault queues.
Table 8. Configuration Register (Register Address 0x01)
Bit
[1:0]
Default
Value
00
Type
R/W
Name
Fault queue
2
0
R/W
CT pin polarity
3
0
R/W
INT pin polarity
4
0
R/W
INT/CT mode
[6:5]
00
R/W
Operation mode
7
0
R/W
Resolution
Description
These two bits set the number of undertemperature/overtemperature faults that can
occur before setting the INT and CT pins. This helps to avoid false triggering due to
temperature noise.
00 = 1 fault (default).
01 = 2 faults.
10 = 3 faults.
11 = 4 faults.
This bit selects the output polarity of the CT pin.
0 = active low.
1 = active high.
This bit selects the output polarity of the INT pin.
0 = active low.
1 = active high.
This bit selects between comparator mode and interrupt mode.
0 = interrupt mode.
1 = comparator mode.
These two bits set the operational mode for the ADT7311.
00 = continuous conversion (default). When one conversion is finished, the ADT7311
starts another.
01 = one shot. Conversion time is typically 240 ms.
10 = 1 SPS mode. Conversion time is typically 60 ms. This operational mode reduces the
average current consumption.
11 = shutdown. All circuitry except interface circuitry is powered down.
This bit sets up the resolution of the ADC when converting.
0 = 13-bit resolution. Sign bit + 12 bits gives a temperature resolution of 0.0625°C.
1 = 16-bit resolution. Sign bit + 15 bits gives a temperature resolution of 0.0078°C.
Rev. 0 | Page 14 of 24
Data Sheet
ADT7311
TEMPERATURE VALUE REGISTER
ID REGISTER
The temperature value register stores the temperature measured
by the internal temperature sensor. The temperature is stored as
a 16-bit twos complement format. The temperature is read back
from the temperature value register (Register Address 0x02) as a
16-bit value.
This 8-bit read-only register (Register Address 0x03) stores
the manufacturer ID in Bit 7 to Bit 3 and the silicon revision
in Bit 2 to Bit 0.
Bit 2, Bit 1, and Bit 0 are event alarm flags for TCRIT, THIGH, and
TLOW. When the ADC is configured to convert the temperature
to a 16-bit digital value, Bit 2, Bit 1, and Bit 0 are no longer used
as flag bits and are, instead, used as the LSB bits for the extended
digital value.
TCRIT SETPOINT REGISTER
The 16-bit TCRIT setpoint register (Register Address 0x04) stores
the critical overtemperature limit value. A critical overtemperature
event occurs when the temperature value stored in the temperature value register exceeds the value stored in this register. The
CT pin is activated if a critical overtemperature event occurs.
The temperature is stored in twos complement format with the
MSB being the temperature sign bit.
The default setting for the TCRIT setpoint is 147°C.
Table 9. Temperature Value Register (Register Address 0x02)
Bit
0
Default Value
0
Type
R
Name
TLOW flag/LSB0
1
0
R
THIGH flag/LSB1
2
0
R
TCRIT flag/LSB2
[7:3]
[14:8]
15
00000
0000000
0
R
R
R
Temp
Temp
Sign
Description
Flags a TLOW event if the configuration register, Register Address 0x01[7] = 0
(13-bit resolution). When the temperature value is below TLOW, this bit it set to 1.
Contains the Least Significant Bit 0 of the 15-bit temperature value if the
configuration register, Register Address 0x01[7] = 1 (16-bit resolution).
Flags a THIGH event if the configuration register, Register Address 0x01[7] = 0
(13-bit resolution). When the temperature value is above THIGH, this bit it set to 1.
Contains the Least Significant Bit 1 of the 15-bit temperature value if the
configuration register, Register Address 0x01[7] = 1 (16-bit resolution).
Flags a TCRIT event if the configuration register, Register Address 0x01[7] = 0
(13-bit resolution). When the temperature value exceeds TCRIT, this bit it set to 1.
Contains the Least Significant Bit 2 of the 15-bit temperature value if the
configuration register, Register Address 0x01[7] = 1 (16-bit resolution).
Temperature value in twos complement format.
Temperature value in twos complement format.
Sign bit, indicates if the temperature value is negative or positive.
Table 10. ID Register (Register Address 0x03)
Bit
[2:0]
[7:3]
Default Value
011
11000
Type
R
R
Name
Revision ID
Manufacturer ID
Description
Contains the silicon revision identification number.
Contains the manufacturer identification number.
Table 11. TCRIT Setpoint Register (Register Address 0x04)
Bit
Default Value
Type
Name
Description
[15:0]
0x4980
R/W
TCRIT
16-bit critical overtemperature limit, stored in twos complement format.
Rev. 0 | Page 15 of 24
ADT7311
Data Sheet
THYST SETPOINT REGISTER
The THYST setpoint 8-bit register (Register Address 0x05) stores
the temperature hysteresis value for the THIGH, TLOW, and TCRIT
temperature limits. The temperature hysteresis value is stored in
straight binary format using four LSBs. Increments are possible
in steps of 1°C from 0°C to 15°C. The value in this register is
subtracted from the THIGH and TCRIT values and added to the
TLOW value to implement hysteresis.
The default setting for the THYST setpoint is 5°C.
THIGH SETPOINT REGISTER
The 16-bit THIGH setpoint register (Register Address 0x06) stores
the overtemperature limit value. An overtemperature event
occurs when the temperature value stored in the temperature
value register exceeds the value stored in this register. The INT pin
is activated if an overtemperature event occurs. The temperature
is stored in twos complement format with the most significant
bit being the temperature sign bit.
The default setting for the THIGH setpoint is 64°C.
TLOW SETPOINT REGISTER
The 16-bit TLOW setpoint register (Register Address 0x07) stores
the undertemperature limit value. An undertemperature event
occurs when the temperature value stored in the temperature
value register is less than the value stored in this register. The
INT pin is activated if an undertemperature event occurs. The
temperature is stored in twos complement format with the MSB
being the temperature sign bit.
The default setting for the TLOW setpoint is 10°C.
Table 12. THYST Setpoint Register (Register Address 0x05)
Bit
Default Value
Type
Name
Description
[3:0]
0101
R/W
THYST
Hysteresis value, from 0°C to 15°C. Stored in straight binary format. The default setting is 5°C.
[7:4]
0000
R/W
N/A
Not used.
Table 13. THIGH Setpoint Register (Register Address 0x06)
Bit
Default Value
Type
Name
Description
[15:0]
0x2000
R/W
THIGH
16-bit overtemperature limit, stored in twos complement format.
Table 14. TLOW Setpoint Register (Register Address 0x07)
Bit
Default Value
[15:0]
0x0500
Type
Name
Description
R/W
TLOW
16-bit undertemperature limit, stored in twos complement format.
Rev. 0 | Page 16 of 24
Data Sheet
ADT7311
SERIAL PERIPHERAL INTERFACE
PULL-UP
VDD
VDD
VDD
ADT7311
SCLK
DOUT
DIN
CS
10kΩ
GND
CT
INT
09050-014
MICROCONTROLLER
10kΩ
0.1µF
Figure 14. Typical SPI Interface Connection
The ADT7311 has a 4-wire serial peripheral interface (SPI). The
interface has a data input pin (DIN) for inputting data to the
device, a data output pin (DOUT) for reading data back from
the device, and a data clock pin (SCLK) for clocking data into
and out of the device. A chip select pin (CS) enables or disables
the serial interface. CS is required for correct operation of the
interface. Data is clocked out of the ADT7311 on the negative
edge of SCLK, and data is clocked into the device on the
positive edge of SCLK.
Bit C7, Bit C2, Bit C1, and Bit C0 of the command byte must all
be set to 0 to successfully begin a bus transaction. The SPI
interface does not work correctly if a 1 is written into any of
these bits.
Bit C6 is the read/write bit; 1 indicates a read, and 0 indicates
a write.
Bits[C5:C3] contain the target register address. One register can
be read from or written to per bus transaction.
SPI COMMAND BYTE
All data transactions on the bus begin with the master taking
CS from high to low and sending out the command byte. This
indicates to the ADT7311 whether the transaction is a read or
a write and provides the address of the register for the data
transfer. Table 15 shows the format of the command byte.
Table 15. Command Byte
C7
0
C6
R/W
C5
C4
C3
Register address
C2
0
C1
0
C0
0
Rev. 0 | Page 17 of 24
ADT7311
Data Sheet
Figure 15 shows a write to an 8-bit register, and Figure 16 shows
a write to a 16-bit register.
WRITING DATA
Data is written to the ADT7311 in eight bits or 16 bits, depending
on the addressed register. The first byte written to the device is
the command byte, with the read/write bit set to 0. The master
then supplies the 8-bit or 16-bit input data on the DIN line.
The ADT7311 clocks the data into the register addressed in
the command byte on the positive edge of SCLK. The master
finishes the write by pulling CS high.
The master must begin a new write transaction on the bus for
every register write. Only one register is written to per bus
transaction.
CS
1
2
3
4
5
6
7
8
9
10
11
DIN
0
R/W
C6
REGISTER ADDR
0
0
0
C4
C2
C1
C0
C5
C3
13
14
15
16
8-BIT DATA
8-BIT COMMAND BYTE
C7
12
D7
D6
D5
D4
D3
D2
D1
09050-028
SCLK
D0
Figure 15. Writing to an 8-Bit Register
CS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
DIN
R/W
C7
C6
REGISTER ADDR
0
0
0
C5
C2
C1
C0
C4
C3
16
17
22
23
24
16-BIT DATA
8-BIT COMMAND BYTE
0
15
D15
D14
D13
D12
D11
D10
Figure 16. Writing to a 16-Bit Register
Rev. 0 | Page 18 of 24
D9
D8
D7
D2
D1
D0
09050-029
SCLK
Data Sheet
ADT7311
CS can be tied to ground, and the serial interface can be
operated in a 3-wire mode. DIN, DOUT, and SCLK are
used to communicate with the ADT7311 in this mode.
READING DATA
A read transaction begins when the master writes the command
byte to the ADT7311 with the read/write bit set to 1. The master
then supplies eight or 16 clock pulses, depending on the addressed
register, and the ADT7311 clocks out data from the addressed
register on the DOUT line. Data is clocked out on the first
falling edge of SCLK following the command byte.
For microcontroller interfaces, it is recommended that SCLK
idle high between data transfers.
SERIAL INTERFACE RESET
The serial interface can be reset by writing a series of 1s on the
DIN input. If a Logic 1 is written to the ADT7311 line for at
least 32 serial clock cycles, the serial interface is reset. This
ensures that the interface can be reset to a known state if the
interface gets lost due to a software error or some glitch in the
system. Reset returns the interface to the state in which it is
expecting a write to the communications register. This operation resets the contents of all registers to their power-on values.
Following a reset, the user should allow a period of 500 μs
before addressing the serial interface.
The read transaction finishes when the master takes CS high.
INTERFACING TO DSPs OR MICROCONTROLLERS
The ADT7311 can be operated with CS used as a frame synchronization signal. This scheme is useful for DSP interfaces.
In this case, the first bit (MSB) is effectively clocked out by CS
because CS normally occurs after the falling edge of SCLK in
DSPs. SCLK can continue to run between data transfers,
provided that the timing specifications in Table 2 are obeyed.
CS
SCLK
2
1
4
3
5
7
6
9
8
11
10
12
13
14
16
15
8-BIT COMMAND WORD
DIN
0
R/W
C7
C6
REGISTER ADDR
C5
C4
C3
0
0
0
C2
C1
C0
DOUT
D7
D6
D5
D4
D3
15
16
D2
D1
09050-030
8-BIT DATA
D0
Figure 17. Reading from an 8-Bit Register
CS
SCLK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
17
22
23
24
8-BIT COMMAND BYTE
DIN
0
R/W
C7
C6
REGISTER ADDR
0
0
0
C4
C2
C1
C0
C5
C3
DOUT
D15
D14
D13
D12
D11
D10
Figure 18. Reading from a 16-Bit Register
Rev. 0 | Page 19 of 24
D9
D8
D7
D2
D1
D0
09050-031
16-BIT DATA
ADT7311
Data Sheet
INT AND CT OUTPUTS
Comparator Mode
The INT and CT pins are open-drain outputs, and both pins
require a 10 kΩ pull-up resistor to VDD. The ADT7311 must be
fully powered up to VDD before reading INT and CT data.
In comparator mode, the INT pin returns to its inactive status
when the temperature drops below the THIGH − THYST limit or
rises above the TLOW + THYST limit.
UNDERTEMPERATURE AND OVERTEMPERATURE
DETECTION
Putting the ADT7311 into shutdown mode does not reset the
INT state in comparator mode.
The INT and CT pins have two undertemperature/overtemperature modes: comparator mode and interrupt mode.
The interrupt mode is the default power-up overtemperature
mode. The INT output pin becomes active when the temperature is greater than the temperature stored in the THIGH setpoint
register or less than the temperature stored in the TLOW setpoint
register. How this pin reacts after this event depends on the
overtemperature mode selected.
Interrupt Mode
In interrupt mode, the INT pin goes inactive when any ADT7311
register is read. When the INT pin is reset, it goes active again
only when the temperature is greater than the temperature
stored in the THIGH setpoint register or less than the temperature
stored in the TLOW setpoint register.
Placing the ADT7311 into shutdown mode resets the INT pin
in the interrupt mode.
Figure 19 illustrates the comparator and interrupt modes for
events exceeding the THIGH limit with both pin polarity settings.
Figure 20 illustrates the comparator and interrupt modes for
events exceeding the TLOW limit with both pin polarity settings.
TEMPERATURE
82°C
81°C
THIGH
80°C
79°C
78°C
77°C
76°C
THIGH – THYST
75°C
74°C
73°C
INT PIN
(COMPARATOR MODE)
POLARITY = ACTIVE LOW
INT PIN
(INTERRUPT MODE)
POLARITY = ACTIVE LOW
INT PIN
(COMPARATOR MODE)
POLARITY = ACTIVE HIGH
TIME
READ
READ
READ
09050-020
INT PIN
(INTERRUPT MODE)
POLARITY = ACTIVE HIGH
Figure 19. INT Output Temperature Response Diagram for THIGH Overtemperature Events
Rev. 0 | Page 20 of 24
Data Sheet
ADT7311
TEMPERATURE
–13°C
–14°C
TLOW + THYST
–15°C
–16°C
–17°C
–18°C
–19°C
TLOW
–20°C
–21°C
–22°C
INT PIN
(COMPARATOR MODE)
POLARITY = ACTIVE LOW
INT PIN
(INTERRUPT MODE)
POLARITY = ACTIVE LOW
INT PIN
(COMPARATOR MODE)
POLARITY = ACTIVE HIGH
TIME
READ
READ
READ
09050-021
INT PIN
(INTERRUPT MODE)
POLARITY = ACTIVE HIGH
Figure 20. INT Output Temperature Response Diagram for TLOW Undertemperature Events
Rev. 0 | Page 21 of 24
ADT7311
Data Sheet
APPLICATIONS INFORMATION
THERMAL RESPONSE TIME
Thermal response is a function of the thermal mass of the
temperature sensor, but it is also heavily influenced by the mass
of the object the IC is mounted to. For example, a large PCB
containing large amounts of copper tracking can act as a large
heat sink and slow the thermal response. For a faster thermal
response, it is recommended to mount the sensor on as small a
PCB as possible.
ADT7311 operates within specification. The RC filter should be
mounted as far away as possible from the ADT7311 to ensure
that the thermal mass is kept as low as possible. For additional
information, contact Analog Devices.
TEMPERATURE MONITORING
SUPPLY DECOUPLING
The ADT7311 is ideal for monitoring the thermal environment
within hazardous automotive applications. The die accurately
reflects the thermal conditions that affect nearby integrated
circuits.
The ADT7311 must have a decoupling capacitor connected
between VDD and GND; otherwise, incorrect temperature
readings will be obtained. A 0.1 μF decoupling capacitor, such
as a high frequency ceramic type, must be used and mounted as
close as possible to the VDD pin of the ADT7311.
The ADT7311 measures and converts the temperature at the
surface of its own semiconductor chip. When the ADT7311 is
used to measure the temperature of a nearby heat source, the
thermal impedance between the heat source and the ADT7311
must be considered.
If possible, the ADT7311 should be powered directly from the
system power supply. This arrangement, shown in Figure 21,
isolates the analog section from the logic-switching transients.
Even if a separate power supply trace is not available, generous
supply bypassing reduces supply line induced errors. Local
supply bypassing consisting of a 0.1 μF ceramic capacitor is
critical for the temperature accuracy specifications to be
achieved.
When the thermal impedance is determined, the temperature
of the heat source can be inferred from the ADT7311 output.
As much as 60% of the heat transferred from the heat source to
the thermal sensor on the ADT7311 die is discharged via the
copper tracks and the bond pads. Of the pads on the ADT7311,
the GND pad transfers most of the heat. Therefore, to measure
the temperature of a heat source, it is recommended that the
thermal resistance between the ADT7311 GND pad and the
GND of the heat source be reduced as much as possible.
TTL/CMOS
LOGIC
CIRCUITS
0.1µF
QUICK GUIDE TO MEASURING TEMPERATURE
ADT7311
POWER
SUPPLY
09050-022
1.
2.
3.
Figure 21. Use of Separate Traces to Reduce Power Supply Noise
POWERING FROM A SWITCHING REGULATOR
Precision analog devices such as the ADT7311 require a wellfiltered power source. If the ADT7311 is powered from a
switching regulator, noise may be generated in the 50 kHz to
3 MHz range that may affect the temperature accuracy specification. To prevent this, it is recommended to connect an RC filter
between the power supply and VDD. The value of components
used should be carefully considered to ensure that the
4.
Rev. 0 | Page 22 of 24
After power-up, reset the serial interface (load 32 consecutive
1s on DIN). This ensures all internal circuitary is properly
initialized.
Verify the setup by reading the device ID (Register Address
0x03). It should read 0xC3.
After consistent consecutive readings are obtained from
Step 2, proceed to read the configuration register (0x01),
TCRIT (0x04), THIGH (0x06), and TLOW (0x07). Compare to
the specified defaults in Table 6. If all the readings match,
the interface is operational.
Write to the configuration register to set theADT7311 to
the desired configuration. Read the temperature value
register. It should produce a valid temperature measurement.
Data Sheet
ADT7311
OUTLINE DIMENSIONS
5.00 (0.1968)
4.80 (0.1890)
8
1
5
4
1.27 (0.0500)
BSC
0.25 (0.0098)
0.10 (0.0040)
COPLANARITY
0.10
SEATING
PLANE
6.20 (0.2441)
5.80 (0.2284)
1.75 (0.0688)
1.35 (0.0532)
0.51 (0.0201)
0.31 (0.0122)
0.50 (0.0196)
0.25 (0.0099)
45°
8°
0°
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
COMPLIANT TO JEDEC STANDARDS MS-012-AA
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.
012407-A
4.00 (0.1574)
3.80 (0.1497)
Figure 22. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-8)
Dimensions shown in millimeters and (inches)
ORDERING GUIDE
Model 1, 2
ADT7311WTRZ
ADT7311WTRZ-RL
ADT7311WTRZ-RL7
EVAL-ADT7X10EBZ
Temperature Range 3
–40°C to +150°C
–40°C to +150°C
–40°C to +150°C
Temperature Accuracy 4
±0.5°C
±0.5°C
±0.5°C
Package Description
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
Evaluation Board
Package Option
R-8
R-8
R-8
1
Z = RoHS Compliant Part.
W = Qualified for Automotive Applications.
3
Operating at extended temperatures over prolonged periods depends on the lifetime performance of the part.
4
Maximum accuracy over the −40°C to +105°C temperature range (VDD = 2.7 V to 3.6 V)
2
AUTOMOTIVE PRODUCTS
The ADT7311W models are available with controlled manufacturing to support the quality and reliability requirements of automotive
applications. Note that these automotive models may have specifications that differ from the commercial models; therefore, designers
should review the Specifications section of this data sheet carefully. Only the automotive grade products shown are available for use in
automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to
obtain the specific Automotive Reliability reports for these models.
Rev. 0 | Page 23 of 24
ADT7311
Data Sheet
NOTES
©2011 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D09050-0-9/11(0)
Rev. 0 | Page 24 of 24
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