ADT7410TRZ-REEL7 - Analog Devices, Inc.

±0.5°C Accurate, 16-Bit Digital

C Temperature Sensor

Data Sheet

ADT7410

Rev. A

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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

I2C-compatible interface

8-lead narrow SOIC RoHS-compliant package

APPLICATIONS

Medical equipment

Environmental control systems

Computer thermal monitoring

Thermal protection

Industrial process control

Power system monitors

Hand-held applications

GENERAL DESCRIPTION

The ADT7410 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 temper-

ature 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 0x03).

The ADT7410 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 typi-

cally 210 μA. The ADT7410 has a shutdown mode that powers

down the device and offers a shutdown current of typically 2 μA.

The ADT7410 is rated for operation over the −55°C to +150°C

temperature range.

Pin A0 and Pin A1 are available for address selection, giving the

ADT7410 four possible I2C® addresses. 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.

FUNCTIONAL BLOCK DIAGRAM

Figure 1.

TEMPERATURE

VALUE

CONFIGURATION

THYST

TLOW

THIGH

TCRIT

POINTER

INTERNAL

REFERENCE

TEMPERATURE

SENSOR THIGH

TCRIT

TLOW

INTERNAL

OSCILLATOR

FILTER

LOGIC

Σ-Δ

MODULATOR

VDD

GND

INT

SCL

SDA

I2C INT E RFACE

ADT7410

06560-001

ADT7410 Data Sheet

Rev. A | Page 2 of 24

TABLE OF CONTENTS

Features .............................................................................................. 1

Applications ....................................................................................... 1

General Description ......................................................................... 1

Functional Block Diagram .............................................................. 1

Revision History ............................................................................... 2

Specifications ..................................................................................... 3

I2C 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

1 SPS Mode .................................................................................. 10

Shutdown ..................................................................................... 11

Fault Queue ................................................................................. 11

Temperature Data Format ......................................................... 12

Temp e rature Conversion Formulas ......................................... 12

Registers ........................................................................................... 13

Address Pointer Register ........................................................... 13

Temperature Value Registers .................................................... 13

Status Register ............................................................................. 14

Configuration Register .............................................................. 14

THIGH Setpoint Registers ............................................................. 15

TLOW Setpoint Registers .............................................................. 15

TCRIT Setpoint Registers .............................................................. 15

THYST Setpoint Register ............................................................... 16

ID Register................................................................................... 16

Serial Interface ................................................................................ 17

Serial Bus Address ...................................................................... 17

Writing Data ............................................................................... 18

Reading Data ............................................................................... 19

Reset ............................................................................................. 19

General Call ................................................................................ 19

INT and CT Outputs ...................................................................... 21

Undertemperature and Overtemperature Detection ............ 21

Applications Information .............................................................. 23

Thermal Response Time ........................................................... 23

Supply Decoupling ..................................................................... 23

Temperature Monitoring ........................................................... 23

Outline Dimensions ....................................................................... 24

Ordering Guide .......................................................................... 24

REVISION HISTORY

12/11—Rev. 0 to Rev. A

Changes to Features Section............................................................ 1

Changes to Table 1 ............................................................................ 3

Changes to Figure 5 .......................................................................... 7

Changes to One-Shot Mode Section and 1 SPS Mode

Section .............................................................................................. 10

Changes to Shutdown Section ...................................................... 11

Changes to Table 8 and Table 9 ..................................................... 13

Changes to Table 10 and Table 11 ................................................ 14

Changes to Ordering Guide .......................................................... 24

4/09—Revision 0: Initial Version

Data Sheet ADT7410

Rev. A | Page 3 of 24

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

±0.5 °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

±0.8

°C

= −40°C to +105°C, V

= 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 Twos complement temperature value of the sign bit

plus 12 ADC bits (power-up default resolution)

16 Bits Twos complement temperature value of the sign bit

plus 15 ADC bits (Bit 7 = 1 in the configuration register)

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 modes

Fast Temperature Conversion Time 6 ms First conversion on power-up only

1 SPS Conversion Time

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

= 5.5 V

Output Low Voltage, VOL 0.4 V IOL = 2 mA @ 5.5 V, IOL = 1 mA @ 3.3 V

Output High Voltage, VOH 0.7 × VDD V

Output Capacitance, COUT 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

SCL, SDA Glitch Rejection 50 ns Input filtering suppresses noise spikes of less than 50 ns

Pin Capacitance 5 10 pF

POWER REQUIREMENTS

Supply Voltage

2.7

5.5

Supply Current

At 3.3 V 210 250 µA Peak current while converting, I2C interface inactive

At 5.5 V 250 300 µA Peak current while converting, I2C interface inactive

1 SPS Current

At 3.3 V 46 µA VDD = 3.3 V, 1 SPS mode, TA = 25°C

At 5.5 V 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.

ADT7410 Data Sheet

Rev. A | Page 4 of 24

I2C 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 VDD) and timed from a voltage level of 1.6 V.

Table 2.

Parameter Min Typ Max Unit Test Conditions/Comments

SERIAL INTERFACE1, 2 See Figure 2

SCL Frequency 0 400 kHz

SCL High Pulse Width, tHIGH 0.6 μs

SCL Low Pulse Width, tLOW 1.3 μs

SCL, SDA Rise Time, tR 0.3 μs

SCL, SDA Fall Time, tF 0.3 μs

Hold Time (Start Condition), tHD;STA 0.6 μs After this period, the first clock is generated

Setup Time (Start Condition), tSU;STA 0.6 μs Relevant for repeated start condition

Data Setup Time, tSU;DAT 0.25 μs VDD ≥ 3.0 V

0.35 μs VDD < 3.0 V

Setup Time (Stop Condition), tSU;STO 0.6 μs

Data Hold Time, tHD;DAT (Master) 0 μs

Bus-Free Time (Between Stop and Start Condition), tBUF 1.3 μs

1 Sample tested during initial release to ensure compliance.

2 All input signals are specified with input rise/fall times = 3 ns, measured between the 10% and 90% points. Timing reference points at 50% for inputs and outputs.

Output load = 10 pF.

Timing Diagram

06560-002

tLOW

tRtF

tHD:STA tHD:DAT tSU:DAT

tSU:STA

tHD:STA

tSU:STO

tHIGH

SCL

SDA

tBUF

Figure 2. Serial Interface Timing Diagram

Data Sheet ADT7410

Rev. A | Page 5 of 24

ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating

VDD to GND −0.3 V to +7 V

SDA Voltage to GND

−0.3 V to V

+ 0.3 V

SCL Output Voltage to GND −0.3 V to VDD + 0.3 V

A0 Input Voltage to GND −0.3 V to VDD + 0.3 V

A1 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

Operating Temperature Range −55°C to +150°C

Storage Temperature Range −65°C to +160°C

Maximum Junction Temperature, TJMAX 150°C

8-Lead SOIC-N (R-8)

Power Dissipation1 WMAX = (TJMAX − TA2)/θJA

Thermal Impedance3

θJA, Junction-to-Ambient (Still Air) 121°C/W

θJC, Junction-to-Case 56°C/W

IR Reflow Soldering 220°C

Peak Temperature (RoHS-Compliant

Package)

260°C (0°C)

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. See 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.

Figure 3. SOIC_N Maximum Power Dissipation vs. Temperature

ESD CAUTION

06560-003

TEMPERATURE (°C)

MAXIMUM POWER DISSIPATIO N (W)

1.2

0.8

1.0

0.6

0.2

0.4

–55

–50

–40

–30

–20

–10

100

110

120

130

140

150

MAX P D = 3.4mW AT 150° C

ADT7410 Data Sheet

Rev. A | Page 6 of 24

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

Figure 4. Pin Configuration

Table 4. Pin Function Descriptions

Pin No. Mnemonic Description

1 SCL I2C Serial Clock Input. The serial clock is used to clock in and clock out data to and from any register of the ADT7410.

Open-drain configuration. A pull-up resistor is required, typically 10 kΩ.

SDA

C Serial Data Input/Output. Serial data to and from the part is provided on this pin. Open-drain configuration. A

pull-up resistor is required, typically 10 kΩ.

3 A0 I2C Serial Bus Address Selection Pin. Logic input. Connect to GND or VDD to set an I2C address.

4 A1 I2C Serial Bus Address Selection Pin. Logic input. Connect to GND or VDD to set an I2C address.

5 INT Overtemperature and Undertemperature Indicator. Logic output. Power-up default setting is as an active low

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.

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 ground.

SCL

SDA

GND

INT

ADT7410

TOP VIEW

(Not t o Scale)

06560-005

Data Sheet ADT7410

Rev. A | Page 7 of 24

TYPICAL PERFORMANCE CHARACTERISTICS

Figure 5. Temperature Accuracy at 3 V

Figure 6. Temperature Accuracy at 5 V

Figure 7. Operating Supply Current vs. Temperature

Figure 8. Shutdown Current vs. Temperature

06560-006

–60 –40 –20 020 40 60 80 100 120 140 160

TEMPERATURE E RROR (° C)

TEMPERATURE ( °C)

–1.0

–0.8

–0.6

–0.4

–0.2

0.2

0.4

0.6

0.8

1.0

MAX ACCURACY LIM IT S

06560-024

–1.0

–0.8

–0.6

–0.4

–0.2

0.2

0.4

0.6

0.8

1.0

–60 –40 –20 020 40 60 80 100 120 140 160

TEMPERATURE E RROR (° C)

TEMPERATURE ( °C)

MAX ACCURACY LIM IT S

0.05

0.10

0.15

0.20

0.25

0.30

–100 –50 050 100 150 200

IDD (mA)

TEMPERATURE ( °C)

3.0V 1S P S

5.5V 1S P S

5.5V CONTINUO US

CONVERSION

3.0V CONTINUO US

CONVERSION

06560-007

3.6V

06560-025

SHUT DOWN I

(µA)

TEMPERATURE ( °C)

–100 –50 050 100 150 200

3.3V

3.0V

2.7V

4.5V

5.0V

5.5V

ADT7410 Data Sheet

Rev. A | Page 8 of 24

Figure 9. Average Operating Supply Current vs. Supply Voltage at 25°C

Figure 10. Shutdown Current vs. Supply Voltage at 25°C

Figure 11. Response to Thermal Shock

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

IDD ( mA)

SUPPLY VOLT AGE (V)

IDD CONT INUOUS CONVE RS ION

IDD 1SPS

06560-008

2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

SHUT DOWN IDD (µA)

SUPPLY VOLTAGE (V)

06560-009

100

120

140

160

0403530252015105

TEMPERATURE (°C)

TIME (Seconds)

06560-011

Data Sheet ADT7410

Rev. A | Page 9 of 24

THEORY OF OPERATION

CIRCUIT INFORMATION

The ADT7410 is a 13-bit digital temperature sensor that is extend-

able to 16 bits for greater resolution. An on-board temperature

sensor generates a voltage proportional to absolute temperature,

which is compared to an internal voltage reference and input to a

precision digital modulator.

The on-board temperature sensor has excellent accuracy

and linearity over the entire rated temperature range without

needing correction or calibration by the user.

The sensor output is digitized by a sigma-delta (Σ-Δ) modulator,

also known as the charge balance type analog-to-digital conver-

ter. This type of converter utilizes time-domain oversampling

and a high accuracy comparator to deliver 16 bits of resolution

in an extremely compact circuit.

Configuration register functions consist of

 Switching between 13-bit and 16-bit resolution

 Switching between normal operation and full power-down

 Switching between comparator and interrupt event modes

on the INT and CT pins

 Setting the active polarity of the CT and INT pins

 Setting the number of faults that activate CT and INT

 Enabling the standard one-shot mode and 1 SPS mode

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 I2C temperature data.

Σ-∆ MODULATOR

INTEGRATOR

COMPARATOR

TEMPERATURE

VALUE

CLOCK

GENERATOR

LPF DIGITAL

FILTER

1-BIT

DAC

VOLTAGE REF

AND VPTAT

1-BIT

13-BIT

6560-012

Figure 12. Σ-Δ Modulator

TEMPERATURE MEASUREMENT

In normal mode, the ADT7410 runs an automatic conversion

sequence. During this automatic conversion sequence, a conver-

sion takes 240 ms to complete and the ADT7410 is continuously

converting. This means that as soon as one temperature conver-

sion is completed, another temperature conversion begins. Each

temperature conversion result is stored in the temperature value

registers and is available through the I2C 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

point 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.

ADT7410 Data Sheet

Rev. A | Page 10 of 24

ONE-SHOT MODE

When one-shot mode is enabled, the ADT7410 immediately

completes a conversion and then goes into shutdown mode. The

one-shot mode is useful when one of the circuit design priorities is

to reduce power consumption.

To enable one-shot mode, set Bits[6:5] of the configuration

After writing to the operation mode bits, wait at least 240 ms

before reading back the temperature from the temperature value

to power up and complete a conversion.

To obtain an updated temperature conversion, reset Bits[6:5] of the

configuration register (Register Address 0x03) to 01.

1 SPS 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 0x03).

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 the comparator mode, if the temperature

drops below the THIGH – THYST value or goes above the TLOW +

THYST value, a write to the one-shot bits (Bit 5 and Bit 6 of the

configuration register, Register Address 0x03) resets the INT pin.

For the CT pin in the comparator mode, if the temperature

drops below the TCRIT – THYST value, a write to the one-shot

bits (Bit 5 and Bit 6 of the configuration register, Register

Address 0x03) resets the CT pin. See Figure 13.

Note that when using one-shot mode, ensure that the refresh

rate is appropriate to the application being used.

Figure 13. One-Shot CT Pin

TEMPERATURE

149°C

148°C

147°C

146°C

145°C

144°C

143°C

142°C

141°C

140°C

CT PIN

POLARITY = ACTIVE LOW

CT PIN

POLARITY = ACTIVE HIGH

CRIT

CRIT – THYST

TIME

*THE RE IS A 240ms DELAY BETWE E N WRITI NG TO THE CONFIGURATION REGISTER TO START

A STANDARD ONE- S HOT CONVERS IO N AND THE CT PI N GO ING ACTIVE. THIS IS DUETO THE

CONVERSION TIME. T HE DELAY I S 60ms IN T HE CAS E OF A 1 SPS CONVERSION.

WRITE TO

BIT 5 AND BI T 6 OF

CONFIGURATION

WRITE TO

BIT 5 AND BI T 6 OF

CONFIGURATION

WRITE TO

BIT 5 AND BI T 6 OF

CONFIGURATION

06560-013

Data Sheet ADT7410

Rev. A | Page 11 of 24

SHUTDOWN

The ADT7410 can be placed in shutdown mode by writing 1

to Bit 6 and 1 to Bit 5 of the configuration register (Register

Address 0x03), in which case the entire IC is shut down and

no further conversions are initiated until the ADT7410 is

taken out of shutdown mode. The ADT7410 can be taken

out of shutdown mode by writing 0 to Bit 6 and 0 to Bit 5 in

the configuration register (Register Address 0x03). The

ADT7410 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 ADT7410 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

0x03) are used to set up a fault queue. The queue can facilitate up

to four fault events to prevent false tripping of the INT and CT pins

when the ADT7410 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 back to zero.

ADT7410 Data Sheet

Rev. A | Page 12 of 24

TEMPERATURE DATA FORMAT

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 ADT7410 is guaranteed to measure a low value

temperature limit of −55°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.

Temperature data in the temperature value register, the TCRIT

setpoint register, the THIGH setpoint register, and the TLOW

setpoint register are 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 conver-

sion 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.

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 confi-

guration register (Register Address 0x03). 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 ADT7410 by ignoring the last four

LSBs of the 13-bit temperature value. These four LSBs are Bit 6

to Bit 3 in Table 5.

Table 5. 13-Bit Temperature Data Format

Temperature

Digital Output

(Binary) Bits[15:3] Digital Output (Hex)

−55°C 1 1100 1001 0000 0x1C90

−50°C 1 1100 1110 0000 0x1CE0

−25°C 1 1110 0111 0000 0x1E70

−0.0625°C 1 1111 1111 1111 0x1FFF

0°C 0 0000 0000 0000 0x000

+0.0625°C 0 0000 0000 0001 0x001

+25°C 0 0001 1001 0000 0x190

+50°C 0 0011 0010 0000 0x320

+125°C 0 0111 1101 0000 0x7D0

+150°C 0 1001 0110 0000 0x960

TEMPERATURE CONVERSION FORMULAS

16-Bit Temperature Data Format

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 Bit 15 (sign bit) 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 the first 13 MSBs of the data byte,

including the sign bit.

Negative Temperature = (ADC Code (dec) – 4096)/16

where Bit 15 (sign bit) 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 Bit 9 (sign bit) is removed from the ADC code.

9-Bit Temperature Data Format

Positive Temperature = ADC Code (dec)

Negative Temperature = ADC Code (dec) − 512

where ADC Code uses all nine bits of the data byte, including

the sign bit.

Negative Temperature = ADC Code (dec) − 256

where Bit 8 (sign bit) is removed from the ADC code.

Data Sheet ADT7410

Rev. A | Page 13 of 24

REGISTERS

The ADT7410 contains 14 registers:

• Nine temperature registers

• A status register

• An ID register

• A configuration register

• An address pointer register

• A software reset

All registers are eight bits wide. The temperature value registers,

the status register, and the ID register are read-only. The software

reset is a write-only register. On power-up, the address pointer

Table 6. ADT7410 Registers

Address Description

Power-On

Default

0x00 Temperature value most significant byte 0x00

0x01 Temperature value least significant byte 0x00

0x02 Status 0x00

0x03 Configuration 0x00

0x04

HIGH

setpoint most significant byte

0x20 (64°C)

0x05 THIGH setpoint least significant byte 0x00 (64°C)

0x06 TLOW setpoint most significant byte 0x05 (10°C)

0x07 TLOW setpoint least significant byte 0x00 (10°C)

0x08 TCRIT setpoint most significant byte 0x49 (147°C)

0x09 TCRIT setpoint least significant byte 0x80 (147°C)

0x0A THYST setpoint 0x05 (5°C)

0x0B ID 0xCX

0x2F Software reset 0xXX

ADDRESS POINTER REGISTER

This register is always the first register written to during a write

to the ADT7410. It should be set to the address of the register

to which the write or read transaction is intended. Table 7

shows the register address of each register on the ADT7410.

The default value of the address pointer register is 0x00.

Table 7. Address Pointer Register

P7 P6 P5 P4 P3 P2 P1 P0

ADD7 ADD6 ADD5 ADD4 ADD3 ADD2 ADD1 ADD0

TEMPERATURE VALUE REGISTERS

The temperature value most significant byte (MSB) and tem-

perature value least significant byte (LSB) registers store the

temperature measured by the internal temperature sensor.

The temperature is stored in twos complement format with

the MSB being the temperature sign bit. When reading from

these registers, the eight MSBs (Bit 7 to Bit 15) are read first

from Register Address 0x00 and then the eight LSBs (Bit 0 to

Bit 7) are read from Register Address 0x01. Only the tempera-

ture value most significant byte (Register Address 0x00) needs to

be loaded into the address pointer register as the address pointer

auto-increments to the Temperature value least significant byte

address (Register Address 0x01).

Bit 0 to Bit 2 are event alarm flags for TCRIT, THIGH, and TLOW. When

the ADC is configured to convert the temperature to a 16-bit

digital value then Bit 0 to Bit 2 are no longer used as flag bits

and are instead used as the LSB bits for the extended digital value.

Table 8. Temperature Value MSB Register (Register Address 0x00)

Bit Default Value Type Name Description

[14:8] 0000000 R Temp Temperature value in twos complement format

15 0 R Sign Sign bit, indicates if the temperature value is negative or positive

Table 9. Temperature Value LSB Register (Register Address 0x01)

Bit

Default

Value Type Name Description

0 0 R TLOW flag/LSB0 Flags a TLOW event if the configuration register, Register Address 0x03[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

1 0 R THIGH flag/LSB1 Flags a THIGH event if the configuration register, Register Address 0x03[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

2 0 R TCRIT flag/LSB2 Flags a TCRIT event if the configuration register, Register Address 0x03[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

[7:3] 00000 R Temp Temperature value in twos complement format.

ADT7410 Data Sheet

Rev. A | Page 14 of 24

STATUS REGISTER

This 8-bit read-only register reflects the status of the overtempera-

ture 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 one-shot bits.

CONFIGURATION REGISTER

This 8-bit read/write register stores various configuration modes

for the ADT7410, including shutdown, overtemperature and

undertemperature interrupts, one-shot, continuous conversion,

interrupt pins polarity, and overtemperature fault queues.

Table 10. Status Register (Register Address 0x02)

Bit

Default

Value Type Name Description

[3:0] 0000 R Unused Reads back 0.

4 0 R TLOW 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 setpoint TLOW + THYST registers.

5 0 R THIGH This bit is set to 1 when the temperature goes above the THIGH temperature limit. The bit clears to 0

when the status register is read and/or when the temperature measured goes back below the limit

set in the setpoint THIGH − THYST registers.

CRIT

This bit is set to 1 when the temperature goes above the T

CRIT

temperature limit. This bit clears to 0

when the status register is read and/or when the temperature measured goes back below the limit

set in the setpoint TCRIT − THYST registers.

RDY

This bit goes low when the temperature conversion result is written into the temperature value

this bit is reset after a write to the one-shot bits.

Table 11. Configuration Register (Register Address 0x03)

Bit

Default

Value Type Name Description

[1:0] 00 R/W Fault queue 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.

2 0 R/W CT pin polarity This bit selects the output polarity of the CT pin.

0 = active low.

1 = active high.

3 0 R/W INT pin polarity This bit selects the output polarity of the INT pin.

0 = active low.

1 = active high.

4 0 R/W INT/CT mode This bit selects between comparator mode and interrupt mode.

0 = interrupt mode

1 = comparator mode

[6:5] 00 R/W Operation mode These two bits set the operational mode for the ADT7410.

00 = continuous conversion (default). When one conversion is finished, the ADT7410 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.

7 0 R/W Resolution 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.

Data Sheet ADT7410

Rev. A | Page 15 of 24

THIGH SETPOINT REGISTERS

The THIGH setpoint MSB and THIGH setpoint LSB registers store

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 temper-

ature is stored in twos complement format with the MSB being

the temperature sign bit.

When reading from this register, the eight MSBs (Bit 15 to Bit 8)

are read first from Register Address 0x04 and then the eight

LSBs (Bit 7 to Bit 0) are read from Register Address 0x05. Only

into the address pointer register as the address pointer auto-

increments to Register Address 0x05 (THIGH setpoint LSB).

The default setting for the THIGH setpoint is 64°C.

TLOW SETPOINT REGISTERS

The TLOW setpoint MSB and TLOW setpoint LSB registers store

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.

When reading from this register, the eight MSBs (Bit 15 to Bit

8) are read first from Register Address 0x06 and then the eight

LSBs (Bit 7 to Bit 0) are read from Register Address 0x07. Only

the Register Address 0x06 (TLOW setpoint MSB) needs to be

loaded into the address pointer register as the address pointer

auto-increments to Register Address 0x07 (TLOW setpoint LSB).

The default setting for the TLOW setpoint is 10°C.

TCRIT SETPOINT REGISTERS

The TCRIT setpoint MSB and TCRIT setpoint LSB registers store

the critical overtemperature limit value. A critical overtempe-

rature event occurs when the temperature value stored in the

temperature value register exceeds the value stored in this

event occurs. The temperature is stored in twos complement

format with the MSB being the temperature sign bit.

When reading from this register, the eight MSBs (Bit 15 to Bit 8)

are read first from Register Address 0x08 and then the eight

LSBs (Bit 7 to Bit 0) are read from Register Address 0x09.

Only the Register Address 0x08 (TCRIT setpoint MSB) needs to

be loaded into the address pointer register as the address pointer

auto-increments to Register Address 0x09 (TCRIT setpoint LSB).

The default setting for the TCRIT limit is 147°C.

Table 12. THIGH Setpoint MSB Register (Register Address 0x04)

Bit

Default Value

Type

Name

Description

[15:8] 0x20 R/W THIGH MSB MSBs of the overtemperature limit, stored in twos complement format.

Table 13. THIGH Setpoint LSB Register (Register Address 0x05)

Bit Default Value Type Name Description

[7:0] 0x00 R/W THIGH LSB LSBs of the overtemperature limit, stored in twos complement format.

Table 14. TLOW Setpoint MSB Register (Register Address 0x06)

Bit Default Value Type Name Description

[15:8] 0x05 R/W TLOW MSB MSBs of the undertemperature limit, stored in twos complement format.

Table 15. TLOW Setpoint LSB Register (Register Address 0x07)

Bit Default Value Type Name Description

[7:0] 0x00 R/W TLOW LSB LSBs of the undertemperature limit, stored in twos complement format.

Table 16. TCRIT Setpoint MSB Register (Register Address 0x08)

Bit Default Value Type Name Description

[15:8] 0x49 R/W TCRIT MSB MSBs of the critical overtemperature limit, stored in twos complement format.

Table 17. TCRIT Setpoint LSB Register (Register Address 0x09)

Bit Default Value Type Name Description

[7:0] 0x80 R/W TCRIT LSB LSBs of the critical overtemperature limit, stored in twos complement format.

ADT7410 Data Sheet

Rev. A | Page 16 of 24

THYST SETPOINT REGISTER

This 8-bit read/write register 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 imple-

ment hysteresis.

ID REGISTER

This 8-bit read-only register stores the manufacturer ID in Bit 3

to Bit 7 and the silicon revision in Bit 0 to Bit 2.

Table 18. THYST Setpoint Register (Register Address 0x0A)

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 19. ID Register (Register Address 0x0B)

Bit Default Value Type Name Description

[2:0] XXX R Revision ID Contains the silicon revision identification number

[7:3] 11001 R Manufacture ID Contains the manufacturer identification number

Data Sheet ADT7410

Rev. A | Page 17 of 24

SERIAL INTERFACE

Figure 14. Typical I2C Interface Connection

Control of the ADT7410 is carried out via the I2C-compatible

serial interface. The ADT7410 is connected to this bus as a slave

and is under the control of a master device.

Figure 14 shows a typical I2C interface connection.

SERIAL BUS ADDRESS

Like all I2C-compatible devices, the ADT7410 has a 7-bit serial

address. The five MSBs of this address for the ADT7410 are set

to 10010. Pin A1 and Pin A0 set the two LSBs. These pins can

be configured two ways, low and high, to give four different

address options. Table 20 shows the different bus address options

available. The recommended pull-up resistor value on the SDA

and SCL lines is 10 kΩ.

Table 20. I2C Bus Address Options

Binary

Hex

A6 A5 A4 A3 A2 A1 A0

1 0 0 1 0 0 0 0x48

1 0 0 1 0 0 1 0x49

1 0 0 1 0 1 0 0x4A

1 0 0 1 0 1 1 0x4B

The serial bus protocol operates as follows:

1. The master initiates data transfer by establishing a start

condition, defined as a high-to-low transition on the serial

data line, SDA, while the serial clock line, SCL, remains

high. This indicates that an address/data stream is going

to follow. All slave peripherals connected to the serial bus

respond to the start condition and shift in the next eight

bits, consisting of a 7-bit address (MSB first) plus a read/

write (R/W) bit. The R/W bit determines whether data is

written to, or read from, the slave device.

2. The peripheral with the address corresponding to the

transmitted address responds by pulling the data line low

during the low period before the ninth clock pulse, known

as the acknowledge bit. All other devices on the bus then

remain idle while the selected device waits for data to be

read from or written to it. If the R/W bit is a 0, the master

writes to the slave device. If the R/W bit is a 1, the master

reads from the slave device.

3. Data is sent over the serial bus in sequences of nine clock

pulses, eight bits of data followed by an acknowledge bit

from the receiver of data. Transitions on the data line must

occur during the low period of the clock signal and remain

stable during the high period as a low-to-high transition when

the clock is high, which can be interpreted as a stop signal.

4. When all data bytes have been read or written, stop condi-

tions are established. In write mode, the master pulls the

data line high during the 10th clock pulse to assert a stop

condition. In read mode, the master device pulls the data

line high during the low period before the ninth clock

pulse. This is known as a no acknowledge. The master

takes the data line low during the low period before the

10th clock pulse, then high during the 10th clock pulse to

assert a stop condition.

It is not possible to mix read and write in one operation because

the type of operation is determined at the beginning and cannot

subsequently be changed without starting a new operation.

ADT7410

SCL

INT

A0 SDA

GND

10kΩ

PULL-UP

0.1µF

10kΩ

PULL-UP

TO INTERRUPT PIN

ON MICROCONTROLLER

06560-014

ADT7410 Data Sheet

Rev. A | Page 18 of 24

WRITING DATA

It is possible to write either a single byte of data or two bytes to

the ADT7410, depending on which registers are to be written.

Writing a single byte of data requires the serial bus address, the

data register address written to the address pointer register,

followed by the data byte written to the selected data register.

This is shown in Figure 15.

For the THIGH setpoint, TLOW setpoint, and TCRIT setpoint registers,

it is possible to write to both the MSB and the LSB registers in

the same write transaction. Writing two bytes of data to these

registers requires the serial bus address, the data register address

of the MSB register written to the address pointer register,

followed by the two data bytes written to the selected data

If more than the required number of data bytes is written to a

a different register, a start or repeated start is required.

Figure 15. Writing to a Register Followed by a Single Byte of Data

Figure 16. Writing to a Register Followed by Two Bytes of Data

FRAM E 1

SERIAL BUS ADDRES S BY TE FRAM E 2

ADDRESS P OINTER RE GIS TER BY TE

ACK. BY

ADT7410 ACK. BY

ADT7410

ACK. BY

ADT7410 STOP BY

MASTER

FRAM E 3

DATA BYTE

SDA (CONTINUED)

SCL (CONT INUED)

SCL

SDA

START BY

MASTER

1 0 0 1 0 A1 A0 P7 P6 P5 P4 P3 P2 P1 P0

D7 D6 D5 D4 D3 D2 D1 D0

R/W

191

06560-016

FRAM E 1

SERIAL BUS ADDRES S BY TE FRAM E 2

ADDRESS P OINTER RE GIS TER BY TE

ACK. BY

ADT7410 ACK. BY

ADT7410

ACK. BY

ADT7410 STOP BY

MASTER

FRAM E 4

DATA BYTE

SCL

SDA

START BY

MASTER

1 0 0 1 0 A1 A0 P7 P6 P5 P4 P3 P2 P1 P0

D7 D6 D5 D4 D3 D2 D1 D0

R/W

191

ACK. BY

ADT7410

FRAM E 3

DATA BYTE

SDA (CONTINUED)

SCL (CONT INUED)

D15 D14 D13 D12 D11 D10 D9 D8

06560-017

Data Sheet ADT7410

Rev. A | Page 19 of 24

READING DATA

Reading data from the ADT7410 is done in a single data byte

operation for the configuration register, the status register,

the THYST register, and the ID register. A two data byte read

operation is needed for the temperature value register, THIGH

setpoint register, TLOW setpoint register, and the TCRIT setpoint

to the configuration register is shown in Figure 17. Reading

back the contents of the temperature value register is shown

in Figure 18.

Reading back from any register first requires a single-byte write

operation to the address pointer register to set up the address of

the register that is going to be read from. In the case of reading

back from the 2-byte registers, the address pointer automatically

increments from the MSB register address to the LSB register

address.

To read from another register, execute another write to the

address pointer register to set up the relevant register address.

Thus, block reads are not possible, that is, there is no I2C address

pointer auto-increment except when reading back from a 16-bit

up with the address of the register that is going to receive a read

command, there is no need to repeat a write operation to set up

the register address again.

RESET

To reset the ADT7410 without having to reset the entire I2C bus,

an explicit reset command is provided. This uses a particular

address pointer word as a command word to reset the part and

upload all default settings. The ADT7410 does not respond to

the I2C bus commands (do not acknowledge) during the default

values upload for approximately 200 µs.

The reset command address word is 0x2F.

GENERAL CALL

When a master issues a slave address consisting of seven 0s with

the eighth bit (R/W bit) set to 0, this is known as the general call

address. The general call address is for addressing every device

connected to the I2C bus. The ADT7410 acknowledges this address

and reads in the following data byte.

If the second byte is 0x06, the ADT7410 is reset, completely

uploading all default values. The ADT7410 does not respond

to the I2C bus commands (do not acknowledge) while the

default values upload for approximately 200 µs.

The ADT7410 does not acknowledge any other general call

commands.

Figure 17. Reading Back Data from the Configuration Register

SCL

SDA

1 0 0 1 A20A0

REPEAT START

BY MASTER FRAM E 3

SERIAL BUS ADDRESS

BYTE

FRAM E 4

DATA BYTE FROM CONFIGURATION

STOP BY

MASTER

ACK. BY

ADT7410 NO ACK. BY

MASTER

R/W D7 D6 D5 D4 D3 D2 D1 D0

9 91

06560-018

SCL

SDA

1 0

0 1 A1 A0

START BY

MASTER FRAM E 1

SERIAL BUS ADDRESS

BYTE

FRAM E 2

ADDRESS P OINTER RE GIS TER BY TE

ACK. BY

ADT7410 ACK. BY

ADT7410

R/W P7 P6 P5 P4 P3 P2 P1 P0

9 91

ADT7410 Data Sheet

Rev. A | Page 20 of 24

NOTES

1. A START CONDITION AT THE BEGINNING IS DEFINED AS A HIGH-TO-LOW TRANSITION ON SDA WHILE SCLK REMAINS HIGH.

2. A STOP CONDITION AT THE END IS DEFINED AS A LOW-TO-HIGH TRANSITION ON SDA WHILE SCLK REMAINS HIGH.

3. THE MASTER GENERATES THE NO ACKNOWLEDGE AT THE END OF THE READBACK TO SIGNAL THAT IT DOES NOT WANT ADDITIONAL DATA.

4. TEMPERATURE REGISTER MSB DATA AND TEMPERATURE REGISTER LSB DATA ARE ALWAYS SEPARATED BY A LOW ACK BIT.

5. THE R/W BIT IS SET TO A1 TO INDICATE A READBACK OPERATION.

SDA

100 R/W A7 A6

SCL

SDA

SCL

1A1 A0

0A1A0

ADT7410 DEVICE ADDRESS REGISTER ADDRESS[A7:A0]

D1 D0

D7 D6

TEMPERATURE REGISTER

MSB DATA

1 19 9

01A1A0

06560-023

R/W

REPEAT

START

D1 D0

D7 D6

ACK. BY

ADT7410

ACK. BY

MASTER

ACK. BY

MASTER

ACK. BY

ADT7410

START

ADT7410 DEVICE ADDRESS ACK. BY

ADT7410 TEMPERATURE REGISTER

LSB DATA

Figure 18. Reading Back Data from the Temperature Value Register

Data Sheet ADT7410

Rev. A | Page 21 of 24

INT AND CT OUTPUTS

The INT and CT pins are open-drain outputs, and both pins

require a 10 kΩ pull-up resistor to VDD.

UNDERTEMPERATURE AND OVERTEMPERATURE

DETECTION

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.

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.

Comparator Mode

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.

Putting the ADT7410 into shutdown mode does not reset the

INT state in comparator mode.

Interrupt Mode

In interrupt mode, the INT pin goes inactive when any ADT7410

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 ADT7410 into shutdown mode resets the INT pin

in the interrupt mode.

Figure 19. INT Output Temperature Response Diagram for THIGH Overtemperature Events

TEMPERATURE

82°C

81°C

80°C

79°C

78°C

77°C

76°C

75°C

74°C

73°C

INT PIN

(COMPARATOR MODE)

POLARITY = ACTIVE LOW

INT PIN

(I NTERRUPT MODE)

POLARITY = ACTIVE LOW

INT PIN

(I NTERRUPT MODE)

POLARITY = ACTIVE HIGH

INT PIN

(COMPARATOR MODE)

POLARITY = ACTIVE HIGH

THIGH

THIGH – THYST

TIME

READ READ READ

06560-020

ADT7410 Data Sheet

Rev. A | Page 22 of 24

Figure 20. INT Output Temperature Response Diagram for TLOW Undertemperature Events

TEMPERATURE

–13°C

–14°C

–15°C

–16°C

–17°C

–18°C

–19°C

–20°C

–21°C

–22°C

INT PIN

(COMPARATOR MODE)

POLARITY = ACTIVE LOW

INT PIN

(I NTERRUPT MODE)

POLARITY = ACTIVE LOW

INT PIN

(I NTERRUPT MODE)

POLARITY = ACTIVE HIGH

INT PIN

(COMPARATOR MODE)

POLARITY = ACTIVE HIGH

TLOW + THYST

TLOW

TIME

READ READ READ

06560-021

Data Sheet ADT7410

Rev. A | Page 23 of 24

APPLICATIONS INFORMATION

THERMAL RESPONSE TIME

The time required for a temperature sensor to settle to a specified

accuracy is a function of the thermal mass of the sensor and the

thermal conductivity between the sensor and the object being

sensed. Thermal mass is often considered equivalent to capaci-

tance. Thermal conductivity is commonly specified using the

symbol, Q, and can be thought of as thermal resistance. It is

commonly specified in units of degrees per watt of power

transferred across the thermal joint. The time required for

the part to settle to the desired accuracy is dependent on the

thermal contact established in a particular application and the

equivalent power of the heat source. In most applications, it is

best to determine the settling time empirically.

SUPPLY DECOUPLING

Decouple the ADT7410 with a 0.1 µF ceramic capacitor

between VDD and GND. This is particularly important when

the ADT7410 is mounted remotely from the power supply.

Precision analog products, such as the ADT7410, require a

well-filtered power source. Because the ADT7410 operates

from a single supply, it might seem convenient to tap into the

digital logic power supply. Unfortunately, the logic supply is

often a switch-mode design, which generates noise in the

20 kHz to 1 MHz range. In addition, fast logic gates can

generate glitches hundreds of millivolts in amplitude due

to wiring resistance and inductance.

If possible, the ADT7410 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. This decoupling capacitor must be placed as close

as possible to the VDD pin of the ADT7410.

Figure 21. Use of Separate Traces to Reduce Power Supply Noise

TEMPERATURE MONITORING

The ADT7410 is ideal for monitoring the thermal environment

within electronic equipment. For example, the surface-mounted

package accurately reflects the exact thermal conditions that

affect nearby integrated circuits.

The ADT7410 measures and converts the temperature at the

surface of its own semiconductor chip. When the ADT7410 is

used to measure the temperature of a nearby heat source, the

thermal impedance between the heat source and the ADT7410

must be considered.

When the thermal impedance is determined, the temperature

of the heat source can be inferred from the ADT7410 output.

As much as 60% of the heat transferred from the heat source to

the thermal sensor on the ADT7410 die is discharged via the

copper tracks, the package pins, and the bond pads. Of the

pins on the ADT7410, the GND pin transfers most of the heat.

Therefore, to measure the temperature of a heat source, it is

recommended that the thermal resistance between the GND pin

of the ADT7410 and the GND of the heat source be reduced as

much as possible.

0.1µF

ADT7410

TTL/CMOS

LOGIC

CIRCUITS

POWER

SUPPLY

06560-022

ADT7410 Data Sheet

Rev. A | Page 24 of 24

OUTLINE DIMENSIONS

Figure 22. 8-Lead Standard Small Outline Package [SOIC_N]

Narrow Body

(R-8)

Dimensions shown in millimeters and (inches)

ORDERING GUIDE

Model1 Temperature Range Temperature Accuracy2 Package Description Package Option

ADT7410TRZ

–55°C to +150°C

±0.5°C

8-Lead SOIC_N

R-8

ADT7410TRZ-REEL –55°C to +150°C ±0.5°C 8-Lead SOIC_N R-8

ADT7410TRZ-REEL7 –55°C to +150°C ±0.5°C 8-Lead SOIC_N R-8

EVAL-ADT7X10EBZ Evaluation Board

1 Z = RoHS Compliant Part.

2 Maximum accuracy over the −40°C to +105°C temperature range.

Purchase of licensed I2C components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I2C Patent

Rights to use these components in an I2C system, provided that the system conforms to the I2C Standard Specification as defined by Philips.

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.

COMPLIANT TO JEDEC STANDARDS MS-012-AA

012407-A

0.25 (0.0098)

0.17 (0.0067)

1.27 (0.0500)

0.40 (0.0157)

0.50 (0.0196)

0.25 (0.0099) 45°

8°

0°

1.75 (0.0688)

1.35 (0.0532)

SEATING

PLANE

0.25 (0.0098)

0.10 (0.0040)

8 5

5.00(0.1968)

4.80(0.1890)

4.00 (0.1574)

3.80 (0.1497)

1.27 (0.0500)

BSC

6.20 (0.2441)

5.80 (0.2284)

0.51 (0.0201)

0.31 (0.0122)

COPLANARITY

0.10

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D06560-0-12/11(A)