Analog Devices ADM1022 b Datasheet

Low-Cost PC Temperature

a

FEATURES
External Temperature Measurement with Remote

Diode (Two Channels)
On-Chip Temperature Sensor
Interrupt and Over-Temperature Outputs
Fault Tolerant Fan Control
Brownout Detection
LDCM Support
System Management Bus (SMBus)
Standby Mode to Minimize Power Consumption
Limit Comparison of all Monitored Values

APPLICATIONS
Network Servers and Personal Computers
Microprocessor-Based Office Equipment
Test Equipment and Measuring Instruments

FUNCTIONAL BLOCK DIAGRAM

V

CC

Monitor and Fan Control ASIC

ADM1022

GENERAL DESCRIPTION

The ADM1022 is a low cost temperature monitor and fan con­troller for microprocessor-based systems. The temperature of one
or two remote sensor diodes may be measured, allowing monitor­ing of processor temperature in single- or dual-processor systems.

Measured values can be read out via a serial System Manage­ment Bus, and values for limit comparisons can be programmed
in over the same serial bus.

The ADM1022 also contains a DAC for fan speed control.
Automatic hardware temperature trip points are provided and
the fan will be driven to full speed if they are exceeded.

Finally, the chip has two supply voltage monitors for brownout
detection.

The ADM1022’s 3.0 V to 5.5 V supply voltage range, low supply
current, and SMBus interface make it ideal for a wide range of
applications. These include hardware monitoring and protection
applications in personal computers, electronic test equipment
and office electronics.

V

MON

RST1

RST2

MR

D1+

D1–

D2+/GPI

D2–/THERM

V

CC

20k⍀

BANDGAP

TEMPERATURE

SENSOR

RESET

GENERATOR 1

RESET

GENERATOR 2

ANALOG

MULTIPLEXER

ADM1022

ADDRESS

POINTER

REGISTER

ADC

2.5V

BANDGAP

REFERENCE

GND

SERIAL BUS

INTERFACE

ANALOG

OUTPUT

REGISTER

AND 8-BIT DAC

VALUE AND

LIMIT

REGISTERS

LIMIT

COMPARATORS

INTERRUPT

STATUS

REGISTERS

INT MASK

REGISTER

MASK

GATING

CONFIGURATION

REGISTER

ADD/NTEST_OUT

SDA

SCL

FAN_SPD/NTEST_IN

INT

FAN_OFF

REV. B

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. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices. Trademarks and
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One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © 2003 Analog Devices, Inc. All rights reserved.

ADM1022–SPECIFICATIONS

(TA = T

Parameter Min Typ

MIN

to T

, VCC = V

MAX

1

to V

MIN

, unless otherwise noted.)

MAX

Max Unit Test Conditions

POWER SUPPLY

Supply Voltage, V
Supply Current, I

CC

CC

3.0 3.30 5.5 V

1.4 2.6 mA Interface Inactive, ADC Active

TEMPERATURE-TO-DIGITAL CONVERTER

Internal Sensor Accuracy ± 3 ∞C

± 1 ± 2 ∞CT

= 85∞C, Tested at Wafer Sort

A

Resolution 1 ∞C
External Diode Sensor Accuracy ± 5 ∞C

± 3 ∞CT

= 85∞C, Tested at Wafer Sort

A

Resolution 1 ∞C
Remote Sensor Source Current 60 90 130 mAHigh Level (D+ = D– +0.65 V)

3.5 5.5 7.5 mA Low Level (D+ = D– +0.65 V)

Total Monitoring Cycle Time, t

C

200 ms

ANALOG OUTPUT

Output Voltage Range 0 2.5 V
Total Unadjusted Error, TUE ± 5% I

= 2 mA

L

Full-Scale Error ± 1 ± 3%
Zero Error ± 2 LSB No Load
Differential Nonlinearity, DNL ± 1 LSB Monotonic by Design
Integral Nonlinearity ± 1 LSB
Output Source Current 2 mA
Output Sink Current 1 mA

VOLTAGE MONITOR THRESHOLDS

Reset Threshold, V

MON

, V

CC

2.85 2.925 3.00 V Measured with VCC Falling

Hysteresis 50 mV

MR INPUT

MR Minimum Pulsewidth, t

MR

10 ms

MR Glitch Immunity 100 ns
MR to RST2 Propagation Delay, t

MD

0.5 ms

MR Pull-Up Resistance 10 20 30 kW

RESET OUTPUTS, RST1, RST2

Reset Output Voltage, V

Reset Active Timeout Period, t
VCC to Reset Delay, t

DIGITAL OUTPUT ADD/NTEST_OUT

Output High Voltage, V
Output Low Voltage, V

OL

RP

D

2

OH

OL

140 180 560 ms

20 ms

2.4 V I

0.3 V I

0.4 V

= 1.2 mA

SINK

V

= VTH(MAX)

CC

= 3.0 mA

OUT

OPEN-DRAIN DIGITAL OUTPUTS

(INT, THERM, RST2, RST1)

Output Low Voltage, V
High Level Output Leakage Current, I

OL

OH

0.1 1 mAV

0.4 V I

= –3.0 mA

OUT

= V

OUT

CC

OPEN-DRAIN SERIAL DATA

BUS OUTPUT (SDA)

Output Low Voltage, V
High Level Output Leakage Current, I

OL

OH

0.4 V I

0.1 1 mAV

= –3.0 mA

OUT

= V

OUT

CC

SERIAL BUS DIGITAL INPUTS

(SCL, SDA)

Input High Voltage, V
Input Low Voltage, V

IL

IH

2.1 V (min)

0.8 V (max)
Input Leakage Current ±5 mA
Hysteresis 500 mV

–2–

REV. B

Parameter Min Typ Max Unit Test Conditions

DIGITAL INPUT LOGIC LEVELS

(FAN_SPD/NTEST_IN,

ADD/NTEST_OUT, MR, GPI)

Input High Voltage, V
Input Low Voltage, V

IL

IH

2.2 V

0.8 V

DIGITAL INPUT LEAKAGE CURRENT

(ALL DIGITAL INPUTS)

Input High Current, I
Input Low Current, I
Input Capacitance, C

SERIAL BUS TIMING

Clock Frequency, f
Glitch Immunity, t
Bus Free Time, t
Start Setup Time, t
Start Hold Time, t
Stop Condition Setup Time, t
SCL Low Time, t
SCL High Time, t
SCL, SDA Rise Time, t
SCL, SDA Fall Time, t
Data Setup Time, t
Data Hold Time, t

NOTES

1

Typicals are at TA = 25∞C and represent most likely parametric norm. Standby current typ is measured with VCC = 3.3 V.

2

ADD is a three-state input that may be pulled high, low or left open-circuit.

3

Timing specifications are tested at logic levels of V

Specifications subject to change without notice.

SCLK

SW

BUF

SU:STA

HD:STA

LOW

HIGH

SU:DAT

HD:DAT

IH

IL

IN

3

SU:STO

R

F

= 0.8 V for a falling edge and V

IL

–1 –0.005 mAV

+0.005 +1 mAV
5pF

400 kHz See Figure 1

50 ns See Figure 1

1.3 ms See Figure 1
600 ns See Figure 1
600 ns See Figure 1
600 ns See Figure 1

1.3 ms See Figure 1

0.6 ms See Figure 1
300 ns See Figure 1
300 ns See Figure 1

100 ns See Figure 1
300 ns See Figure 1

= 2.2 V for a rising edge.

IH

IN

IN

= V
= 0

CC

ADM1022

SCLK

SDATA

t

BUF

PS

t

HD;STA

t

LOW

t

R

t

HD;DAT

t

HIGH

t

F

t

SU;DAT

Figure 1. Diagram for Serial Bus Timing

t

HD;STA

t

SU;STA

S

t

SU;STO

P

REV. B

–3–

ADM1022

ABSOLUTE MAXIMUM RATINGS*

Positive Supply Voltage (VCC) . . . . . . . . . . . . . . . . . . . . 6.5 V

Voltage On Digital Inputs Except Therm . . –0.3 V to +6.5 V

Voltage On Therm Pin . . . . . . . . . . . . –0.3 V to V

+ 0.3 V

CC

Voltage on Any Other Input

or Output Pin . . . . . . . . . . . . . . . . . . –0.3 V to V

+ 0.3 V

CC

Input Current at Any Pin . . . . . . . . . . . . . . . . . . . . . . . ± 5 mA

Package Input Current . . . . . . . . . . . . . . . . . . . . . . . ± 20 mA

Maximum Junction Temperature (T

max) . . . . . . . . . . 150∞C

J

Storage Temperature Range . . . . . . . . . . . . –65∞C to +150∞C

Lead Temperature, Soldering

Vapor Phase 60 sec . . . . . . . . . . . . . . . . . . . . . . . . . . 215∞C

Infrared 15 sec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200∞C

ESD Rating (Human Body Model) . . . . . . . . . . . . . . . 4000 V

PIN CONFIGURATION

MR

RST1

GND

V

V

MON

RST2

1

2

3

4

5

CC

6

7

8

FAN_OFF

FAN_SPD/NTEST_IN

*Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent 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

q

= 105∞C/W

JA

= 39∞C/W

q

JA

ORDERING GUIDE

Temperature Package Package

Model Range Description Option

ADM1022ARQ 0∞C to 85∞C 16-Lead QSOP RQ-16

16

SDA

15

SCL

14

INT

ADM1022

TOP VIEW

(Not to Scale)

13

ADD/NTEST_OUT

12

D2+/GPI

11

D2–/THERM

10

D1+

9

D1–

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 the ADM1022 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.

–4–

REV. B

ADM1022

PIN FUNCTION DESCRIPTIONS

Pin
No. Mnemonic Description

1 FAN_OFF Digital Output (Open-Drain) Fan Off Request. When asserted low this indicates a request to shut

off the fan independent of the FAN_SPD output. When negated (output FET off) it indicates that
the fan may be turned on.

2 MR Digital Input, Manual Reset. A logic low on this input causes RST2 to be asserted. Once this input

is negated that output will remain asserted for t
Leave unconnected if not used.

3 RST1 Digital I/O (Open-Drain). This pin is asserted low while V

remains asserted for t

after the reset condition is terminated. It is bidirectional so the ADM1022 can

RP

be optionally reset; external logic must be used to prevent system auxiliary reset from occurring

when used as an input.
4 GND GROUND. Power and Signal Ground.
5V
6V

CC

MON

POWER 3.3 V. Power source and voltage monitor input for first reset generator.

Analog Input. Voltage monitor input for second reset generator.
7 RST2 Digital Output (Open-Drain). This pin is asserted low under any of the following conditions:

– V

or VCC remains below the reset threshold

MON

– while MR is held low

– while RST1 is asserted.

It remains asserted for t

after the reset conditions are terminated.

RP

8 FAN_SPD/NTEST_IN Analog Output/Test Input. An active-high input that enables NAND board-level connectivity testing.

Refer to section on NAND testing. Used as an analog output for fan speed control when NAND

test is not selected.
9 D1– Remote Thermal Diode Negative Input. This is the negative input (current sink) from the remote

thermal diode. This also serves as the negative input into the A/D.
10 D1+ Remote Thermal Diode Positive Input. This is the positive input (current source) from the remote

thermal diode. This serves as the positive input into the A/D.
11 D2–/THERM Analog Input/Digital I/O (Open-Drain). Can be programmed as negative input for a second diode

temperature sensor, or as a digital I/O pin. In this case it is an active low thermal overload output

that indicates a violation of a temperature set point (over-temperature). Also acts as an input to

provide external fan control. When this pin is pulled low by an external signal, a status bit is set and

the fan speed is set to full on.
12 D2+/GPI Analog/Digital Input. Can be programmed as the positive input for a second diode sensor, or as a

general-purpose logic input. In this case it can be programmed as an active high or active low input

that sets Bit 4 of the Status Registers. This bit can only be reset by reading the status registers, pro-

vided GPI is in the inactive state.
13 ADD/NTEST_OUT Digital I/O. The lowest order programmable bit of the SMBus Address. ADD is sampled at power-

up and changing it while powered on will have no immediate effect. This pin also functions as an

output when doing a NAND test.
14 INT Digital Output (Open Drain), System Interrupt Output. This signal indicates a violation of a set

trip point. The output is enabled when Bit 1 of the Configuration Register is set to 1. The default

state is disabled.
15 SCL Digital Input SMBus Clock.
16 SDA Digital I/O (Open-Drain) SMBus Bidirectional Data.

. This input has an internal 20 kW pull-up resistor.

RP

remains below the reset threshold. It

CC

REV. B

–5–

ADM1022

–Typical Performance Characteristics

30

20

10

0

–10

–20

–30

TEMPERATURE ERROR – ⴗC

–40

–50

–60

1 1003.3

LEAKAGE RESISTANCE – M⍀

DXP TO GND

DXP TO VCC (5V)

10 30

TPC 1. Temperature Error vs. PC Leakage Resistance

6

5

4

250mV p-p REMOTE

3

2

120

100

90

80

70

60

50

READING

40

30

20

10

0

0 11010

20 30 40 50

MEASURED TEMPERATURE

60 70 80 90 100

TPC 4. Pentium® III Temperature Measurement vs.
ADM1022 Reading

30

25

20

15

10

ERROR

1

TEMPERATURE ERROR – ⴗC

0

–1

50 50M500

5k

50k

FREQUENCY – Hz

100mV p-p REMOTE

500k 5M

TPC 2. Temperature Error vs. Power Supply Noise
Frequency

25

20

15

10

5

TEMPERATURE ERROR – ⴗC

0

–5

50 50M500

5k 50k 500k 5M

FREQUENCY – Hz

100mV p-p

50mV p-p

25mV p-p

5

TEMPERATURE ERROR – ⴗC

0

–5

1.0 29.02.2

3.2 4.7 7.0
DXP-DXN CAPACITANCE – nF

10.0 14.0 22.0

TPC 5. Temperature Error vs. Capacitance Between D+
and D–

80

70

60

50

40

30

SUPPLY CURRENT – ␮A

20

10

0

0

5k 10k 25k 50k 75k 100k 250k 500k 750k

SCLK FREQUENCY – Hz

VCC = 5V

VCC = 3V

1M1k

TPC 3. Temperature Error vs. Common-Mode Noise
Frequency

Pentium is a registered trademark of Intel Corporation.

–6–

TPC 6. Standby Current vs. Clock Frequency

REV. B