Analog Devices ADM1023 g Datasheet

ACPI Compliant High Accuracy

Microprocessor System Temperature Monitor

FEATURES

Next generation upgrade of ADM1021
On-chip and remote temperature sensing
Offset registers for system calibration
1°C accuracy and resolution on local channel

0.125°C resolution/1°C accuracy on remote channel
Programmable over/under temperature limits
Programmable conversion rate

ALERT

Supports system management bus (SMBus)
2-wire SMBus serial interface
200 µA max operating current (0.25 conversions/seconds)
1 µA standby current
3 V to 5.5 V supply
Small 16-lead QSOP package

APPLICATIONS

Desktop computers
Notebook computers
Smart batteries
Industrial controllers
Telecomms equipment
Instrumentation

ON-CHIP

TEMPERATURE

1

Patents pending.

SENSOR

3

D+

ANALOG

MUX

4

D–

NC V
NC = NO CONNECT

BUSY RUN/STANDBY

EXTERNAL DIODE OPEN-CIRCUIT

1 2 5 7 8 9 13 16 12 14 10 6

DD

LOCAL TEMPERATURE

VALUE REGISTER

A-TO-D

CONVERTER

REMOTE TEMPERATURE

VALUE REGISTERS

ADM1023

GNDNC GND NC NC NC SDATA SCLK ADD0 ADD1

FUNCTIONAL BLOCK DIAGRAM

GENERAL DESCRIPTION

The ADM10231 is a 2-channel digital thermometer and
under/over temperature alarm for use in personal computers
and other systems requiring thermal monitoring and manage­ment. Optimized for the Pentium® III; the higher accuracy
allows systems designers to safely reduce temperature guard
banding and increase system performance. The device can
measure the temperature of a microprocessor using a diode­connected PNP transistor, which may be provided on-chip in
the case of the Pentium III or similar processors, or can be a
low-cost, discrete NPN/PNP device such as the 2N3904/2N3906.
A novel measurement technique cancels out the absolute value
of the transistor’s base emitter voltage so that no calibration is
required. The second measurement channel measures the
output of an on-chip temperature sensor to monitor the
temperature of the device and its environment.

The ADM1023 communicates over a 2-wire serial interface
compatible with SMBus standards. Under- and overtemperature
limits can be programmed into the device over the serial bus,
and an
temperature is out of range. This output can be used as an
interrupt, or as an SMBus

LOCAL TEMPERATURE

LOW-LIMIT COMPARATOR

LOCAL TEMPERATURE

HIGH-LIMIT COMPARATOR

REMOTE TEMPERATURE

LOW-LIMIT COMPARATOR

REMOTE TEMPERATURE

HIGH-LIMIT COMPARATOR

STATUS REGISTER

SMBus INTERFACE

Figure 1.

ALERT

output signals when the on-chip or remote

ALERT

.

ADDRESS POINTER

REGISTER

ONE-SHOT
REGISTER

CONVERSION RATE

REGISTER

OFFSET

REGISTERS

LOCAL TEMPERATURE

LOW-LIMIT REGISTER

LOCAL TEMPERATURE

HIGH-LIMIT REGISTER

REMOTE TEMPERATURE

LOW-LIMIT REGISTERS

REMOTE TEMPERATURE

HIGH-LIMIT REGISTERS

CONFIGURATION

REGISTER

INTERRUPT

MASKING

ADM1023

15

STBY

11

ALERT

00058-001

Rev. G

Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
Fax: [phone] © 2005 Analog Devices, Inc. All rights reserved.

www.analog.com

ADM1023

TABLE OF CONTENTS

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

Serial Bus Interface..................................................................... 12

Absolute Maximum Ratings............................................................ 4

ESD Caution.................................................................................. 4

Pin Configuration and Functional Description ........................... 5

Typical Performance Characteristics ............................................. 6

Theory of Operation ........................................................................ 8

Functional Description................................................................ 8

Measurement Method.................................................................. 9

Sources of Errors on Thermal Transistors Measurement

Method........................................................................................... 9

Temperature Data Format......................................................... 10

Register Functions...................................................................... 10

REVISION HISTORY

2/05—Rev. F to Rev. G

Updated Format.................................................................. Universal

Changes to Specifications.................................................................3

Changes to Absolute Maximum Ratings........................................4

Changes to Figure 14.........................................................................8

Changes to Figure 21.......................................................................17

Changes to Ordering Guide...........................................................18

4/03—Rev. E to Rev. F

Added Reference to Figure 1............................................................2

4/03—Rev. D to Rev. E

Added ESD Caution..........................................................................3

Updated Outline Dimensions........................................................13

Address Pins................................................................................ 12

ALERT

Output............................................................................ 14

Low Power Standby Modes....................................................... 15

Sensor Fault Detection .............................................................. 15

Applications..................................................................................... 16

Factors Affecting Accuracy....................................................... 16

Layout Considerations............................................................... 16

Application Circuits................................................................... 17

Outline Dimensions....................................................................... 18

Ordering Guide .......................................................................... 18

9/02—Rev. C to Rev. D

Outline Dimensions updated...........................................................13

5/02—Rev. B to Rev. C

Figures 2 to 11 changed to TPCs 1–10, renumbered figures

accordingly ......................................................................................... 4

Text change to Figure 9 (TPC 8)......................................................5

Callouts in text added for Tables IV–VI......................................... 8

Change to Serial Bus Interface section ...........................................9

4/00—Revision 0: Initial Version

Rev. G | Page 2 of 20

ADM1023

SPECIFICATIONS

TA = T

MIN

to T

Table 1.

Parameter Min Typ Max Unit Test Conditions/Comments

POWER SUPPLY AND ADC

Temperature Resolution, Local Sensor 1 °C Guaranteed no missed codes
Temperature Resolution, Remote Sensor 0.125 °C Guaranteed no missed codes
Temperature Error, Local Sensor −1.5 ±0.5 +1.5 °C TA = 60°C to 100°C

−3 ±1 +3 °C TA = 0°C to 120°C

Temperature Error, Remote Sensor −1 +1 °C TA, TD = 60°C to 100°C2

−3 +3 °C TA, TD = 0°C to 120°C2
Relative Accuracy 0.25 °C TA = 60°C to 100°C
Supply Voltage Range3 3 3.6 V
Undervoltage Lockout Threshold 2.55 2.7 2.8 V VDD input, disables ADC, rising edge
Undervoltage Lockout Hysteresis 25 mV
Power-On Reset Threshold 0.9 1.7 2.2 V VDD, falling edge4
POR Threshold Hysteresis 50 mV
Standby Supply Current 1 5 µA VDD = 3.3 V, no SMBus activity

4 µA SCLK at 10 kHz
Average Operating Supply Current 130 200 µA 0.25 conversions/sec rate
Autoconvert Mode, Averaged Over 4 Sec 225 330 µA 2 conversions/sec rate
Conversion Time 65 115 170 ms

Remote Sensor Source Current 120 205 300 µA High level4

7 12 16 µA Low level4
D-Source Voltage 0.7 V
Address Pin Bias Current (ADD0, ADD1) 50 µA Momentary at power-on reset

SMBus INTERFACE (See Figure 3)

Logic Input High Voltage, VIH 2.2 V VDD = 3 V to 5.5 V
STBY, SCLK, SDATA
Logic Input Low Voltage, VIL 0.8 V VDD = 3 V to 5.5 V
STBY, SCLK, SDATA
SMBus Output Low Sink Current 6 mA SDATA forced to 0.6 V
ALERT

Output Low Sink Current
Logic Input Current, IIH, IIL −1 +1 µA
SMBus Input Capacitance, SCLK, SDATA 5 pF
SMBus Clock Frequency 400 kHz
SMBus Clock Low Time, t
SMBus Clock High Time, t
SMBus Start Condition Setup Time, t
SMBus Start Condition Hold Time, t
SMBus Stop Condition Setup Time, t
SMBus Data Valid to SCLK Rising Edge Time, t
SMBus Bus Free Time, t
SCLK SDATA Rise Time, t
SCLK SDATA Fall Time, t

1

T

= 120°C, T

MAX

2

TD is temperature of remote thermal diode; TA, TD = 60°C to 100°C.

3

Operation at VDD = 5 V guaranteed by design; not production tested.

4

Guranteed by design, not production tested.

1

, VDD = 3.0 V to 3.6 V, unless otherwise noted.

MAX

1.3 µs t

LOW

0.6 µs t

HIGH

0.6 µs

SU:STA

0.6 µs Time from 10% of SDATA to 90% of SCLK

HD:STA

0.6 µs Time from 90% of SCLK to 10% of SDATA

SU:STO

100 ns Time for 10% or 90% of SDATA to 10% of SCLK

SU:DAT

1.3 µs Between start/stop condition

BUF°

300 ns Master clocking in data

R MAX

300 ns VDD = 0 V

F MAX

= 0°C.

MIN

From stop bit to conversion complete (both
channels) D+ forced to D− + 0.65 V

1 mA

ALERT

forced to 0.4 V

between 10% points

LOW

between 90% points

HIGH

Rev. G | Page 3 of 20

ADM1023

ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameters Ratings

Positive Supply Voltage (VDD) to GND −0.3 V to +6 V
D+, ADD0, ADD1 −0.3 V to VDD + 0.3 V
D− to GND −0.3 V to +0.6 V

SCLK, SDATA,
Input Current ±50 mA
Input Current, D− ±1 mA
ESD Rating, All Pins (Human Body Model) 2000 V
Continuous Power Dissipation

Up to 70°C 650 mW

Derating Above 70°C 6.7 mW/°C
Operating Temperature Range −55°C to +125°C
Maximum Junction Temperature (T
Storage Temperature Range −65°C to +150°C
Lead Temperature (Soldering 10 sec) 300°C
IR Reflow Peak Temperature 220°C
IR Reflow Peak Temperature for Pb-Free 260°C

ALERT, STBY

J MAX

−0.3 V to +6 V

) 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.

THERMAL CHARACTERISTICS

16-lead QSOP package:

θ

= 105°C/W

JA

= 39°C/W

θ

JC

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate
on the human body and test equipment and can discharge without detection. Although this product
features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to
high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid
performance degradation or loss of functionality.

Rev. G | Page 4 of 20

ADM1023

A

PIN CONFIGURATION AND FUNCTION DESCRIPTION

1

NC

2

V

DD

3

D+

ADM1023

4

D–

TOP VIEW

(Not to Scale)

5

NC

6

DD1

7

GND

8

GND NC

NC = NO CONNECT

Figure 2. Pin Configuration

16

15

14

13

12

11

10

9

NC
STBY
SCLK
NC
SDATA
ALERT
ADD0

00058-002

Table 3. Pin Function Description

Pin No. Mnemonic Description

1, 5, 9, 13, 16 NC No Connect.
2 VDD Positive Supply, 3 V to 5.5 V.
3 D+ Positive Connection to Remote Temperature Sensor.
4 D− Negative Connection to Remote Temperature Sensor.
6 ADD1 Three-State Logic Input, Higher Bit of Device Address.
7, 8 GND Supply 0 V Connection.
10 ADD0 Three-State Logic Input, Lower Bit of Device Address.
11

ALERT

Open-Drain Logic Output Used as Interrupt or SMBus

ALERT
12 SDATA Logic Input/Output, SMBus Serial Data. Open-drain output.
14 SCLK Logic Input, SMBus Serial Clock.
15

STBY

Logic Input Selecting Normal Operation (High) or Standby Mode (Low).

.

SCL

SDA

t

t

HD;DAT

t

R

t

HIGH

t

F

t

SU;DAT

t

LOW

t

HD;STA

t

BUF

P

S

Figure 3. Diagram for Serial Bus Timing

t

SU;STA

HD;STA

t

SU;STO

PS

00058-003

Rev. G | Page 5 of 20

ADM1023

TYPICAL PERFORMANCE CHARACTERISTICS

20

15

10

5

0

–5

–10

–15

TEMPERATURE ERROR (°C)

–20

–25

–30

Figure 4. Temperature Error vs. Resistance from Track to V

D+ TO GND

D+ TO V

DD

LEAKAGE RESISTANCE (MΩ)

100110

and GND

DD

00058-004

3

2

1

0

–1

TEMPERATURE ERROR (°C)

–2

–3

UPPER SPEC LEVEL

LOWER SPEC LEVEL

12050 60 70 80 90 100 110

TEMPERATURE (°C)

Figure 7. Temperature Error of ADM1023 vs. Pentium III Temperature

00058-007

5

4

3

2

TEMPERATURE ERROR (°C)

1

0

250mV p-p REMOTE

100mV p-p REMOTE

FREQUENCY (Hz)

Figure 5. Remote Temperature Error vs. Supply Noise Frequency

9

8

7

6

5

4

3

2

TEMPERATURE ERROR (°C)

1

0

100mV p-p

50mV p-p

25mV p-p

FREQUENCY (Hz)

Figure 6. Temperature Error vs. Common-Mode Noise Frequency

14

12

10

8

6

4

2

TEMPERATURE ERROR (°C)

0

100M100 1k 10k 100k 1M 10M

00058-005

–1

CAPACITANCE (nF)

24246810121416182022

00058-008

Figure 8. Temperature Error vs. Capacitance Between D+ and D−

70

60

50

40

30

20

SUPPLY CURRENT (µA)

10

100M1 10 100 1k 10k 100k 1M 10M

00058-006

0

SCLK FREQUENCY (kHz)

VDD = 3.3V

VDD = 5V

10001 5 10 25 50 75 100 250 500 750

00058-009

Figure 9. Standby Supply Current vs. SCLK Frequency

Rev. G | Page 6 of 20