REV. 0

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

which may result from its use. No license is granted by implication or

otherwise under any patent or patent rights of Analog Devices.

ADM1024

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700 World Wide Web Site: http://www.analog.com

Fax: 781/326-8703 © Analog Devices, Inc., 2000

System Hardware Monitor with

Remote Diode Thermal Sensing

FUNCTIONAL BLOCK DIAGRAM

ADDRESS

POINTER

TEMPERATURE

CONFIGURATION

10-BIT ADC

NTEST OUT/ADD

SDA

SCL

2.5V

BANDGAP

REFERENCE

INPUT

ATTENUATORS

AND

ANALOG

MULTIPLEXER

BANDGAP

TEMPERATURE

SENSOR

VID0–3 AND

FAN DIVISOR

VID4 AND

DEVICE ID

100k⍀

PULLUPS

+5V

D1+

D1–

GND

ADM1024

FAN SPEED

COUNTER

+12V

CONFIGURATION

REGISTERS

INTERRUPT

STATUS

REGISTERS

VALUE AND

LIMIT

REGISTERS

LIMIT

COMPARATORS

SERIAL BUS

INTERFACE

CHANNEL

MODE

CHASSIS

INTRUSION

CLEAR

INT MASK

REGISTERS

INTERRUPT

MASKING

ANALOG

OUTPUT

8-BIT DAC

THERM

INT

NTEST

IN/AOUT

RESET

VID0/IRQ0

VID1/IRQ1

VID2/IRQ2

VID3/IRQ3

VID4/IRQ4

CCP1

+2.5V

/D2+

FAN1/AIN1

CCP2

/D2–

FAN2/AIN2

POWER TO CHIP

100k⍀

FEATURES

Up to Nine Measurement Channels

Inputs Programmable-to-Measure Analog Voltage, Fan

Speed or External Temperature

External Temperature Measurement with Remote

Diode (Two Channels)

On-Chip Temperature Sensor

Five Digital Inputs for VID Bits

LDCM Support

System Management Bus (SMBus)

Chassis Intrusion Detect

Interrupt and Over Temperature Outputs

Programmable RESET Input Pin

Shutdown Mode to Minimize Power Consumption

Limit Comparison of all Monitored Values

PRODUCT DESCRIPTION

The ADM1024 is a complete system hardware monitor for

microprocessor-based systems, providing measurement and limit

comparison of various system parameters. Eight measurement

inputs are provided, of which three are dedicated to monitoring

5 V and 12 V power supplies and the processor core voltage.

The ADM1024 can monitor a fourth power-supply voltage by

measuring its own V

. One input (two pins) is dedicated to a

remote temperature-sensing diode. Two further pins can be

(continued on page 7)

APPLICATIONS

Network Servers and Personal Computers

Microprocessor-Based Ofﬁce Equipment

Test Equipment and Measuring Instruments

–2–

REV. 0

ADM1024–SPECIFICATIONS

1, 2

= T

MIN

to T

MAX

, V

= V

MIN

to V

MAX

, unless otherwise noted)

Parameter Min Typ Max Unit Test Conditions/Comments

POWER SUPPLY

Supply Voltage, V

2.8 3.30 5.5 V

Supply Current, I

1.4 2.6 mA Interface Inactive, ADC Active

1.0 mA ADC Inactive, DAC Active

45 145 µA Shutdown Mode

TEMPERATURE-TO-DIGITAL CONVERTER

Internal Sensor Accuracy ± 3 °C0°C ≤ T

≤ 100°C

± 2 °CT

= 25°C

Resolution ± 1 °C

External Diode Sensor Accuracy ± 5 °C0°C ≤ T

≤ 100°C

± 3 °C25°C

Resolution ± 1 °C

Remote Sensor Source Current 80 110 150 µA High Level

4 6.5 9 µA Low Level

ANALOG-TO-DIGITAL CONVERTER

(INCLUDING MUX AND ATTENUATORS)

Total Unadjusted Error, TUE (12 V

) ± 4 % (See Note 3)

TUE (AIN, V

CCP

, 2.5 V

, 5 V

) ± 3%

Differential Nonlinearity, DNL ± 1 LSB

Power Supply Sensitivity ± 1 %/V

Conversion Time (Analog Input or Int. Temp) 754.8 856.8 µs0°C ≤ T

≤ 100°C

Conversion Time (External Temperature) 9.6 ms (See Note 4)

Input Resistance (2.5 V, 5 V, 12 V, V

CCP1

, V

CCP2

) 100 140 200 kΩ

Input Resistance (AIN1, AIN2) 5 MΩ

ANALOG OUTPUT

Output Voltage Range 0 2.5 V

Total Unadjusted Error, TUE ± 3% I

= 2 mA

Full-Scale Error ± 1 ± 5%

Zero-Scale 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

FAN RPM-TO-DIGITAL CONVERTER

Accuracy ± 12 % 0°C ≤ T

≤ 100°C

Full-Scale Count 255

FAN1 and FAN2 Nominal Input RPM

8800 rpm Divisor = 1, Fan Count = 153

4400 rpm Divisor = 2, Fan Count = 153

2200 rpm Divisor = 3, Fan Count = 153

1100 rpm Divisor = 4, Fan Count = 153

Internal Clock Frequency 19.8 22.5 25.2 kHz 0°C ≤ T

≤ 100°C

DIGITAL OUTPUTS NTEST_OUT

Output High Voltage, V

2.4 V I

OUT

= +3.0 mA, V

= 2.85 V – 3.60 V

Output Low Voltage, V

0.4 V I

OUT

= –3.0 mA, V

= 2.85 V – 3.60 V

OPEN-DRAIN DIGITAL OUTPUTS (See Note 6)

(INT, THERM, RESET)

Output Low Voltage, V

0.4 V I

OUT

= –3.0 mA, V

= 3.60 V

High Level Output Current, I

0.1 100 µAV

OUT

= V

RESET and CI Pulsewidth 20 45 ms

OPEN-DRAIN SERIAL DATA BUS OUTPUT

(SDA)

Output Low Voltage, V

0.4 V I

OUT

= –3.0 mA, V

= 2.85 V – 3.60 V

High Level Output Current, I

0.1 100 µAV

OUT

= V

–3–

REV. 0

ADM1024

Parameter Min Typ Max Unit Test Conditions/Comments

SERIAL BUS DIGITAL INPUTS

(SCL, SDA)

Input High Voltage, V

2.2 V

Input Low Voltage, V

0.8 V

Hysteresis 500 mV

Glitch Immunity 100 ns

DIGITAL INPUT LOGIC LEVELS (See Note 7)

(ADD, CI, RESET, VID0–VID4, FAN1, FAN2)

Input High Voltage, V

2.2 V V

= 2.85 V – 5.5 V

Input Low Voltage, V

0.8 V V

= 2.85 V – 5.5 V

NTEST_IN

Input High Voltage, V

2.2 V V

= 2.85 V – 5.5 V

DIGITAL INPUT CURRENT

Input High Current, I

–1 µAV

= V

Input Low Current, I

1 µAV

= 0

Input Capacitance, C

20 pF

SERIAL BUS TIMING

Clock Frequency, f

SCLK

400 kHz See Figure 1

Glitch Immunity, t

50 ns See Figure 1

Bus Free Time, t

BUF

1.3 µs See Figure 1

Start Setup Time, t

SU;STA

600 ns See Figure 1

Start Hold Time, t

HD;STA

600 ns See Figure 1

SCL Low Time, t

LOW

1.3 µs See Figure 1

SCL High Time, t

HIGH

0.6 µs See Figure 1

SCL, SDA Rise Time, t

300 ns See Figure 1

SCL, SDA Fall Time, t

300 µs See Figure 1

Data Setup Time, t

SU;DAT

100 ns See Figure 1

Data Hold Time, t

HD;DAT

900 ns See Figure 1

NOTES

All voltages are measured with respect to GND, unless otherwise speciﬁed.

Typicals are at T

= 25°C and represent most likely parametric norm. Shutdown current typ is measured with V

= 3.3 V.

TUE (Total Unadjusted Error) includes Offset, Gain and Linearity errors of the ADC, multiplexer and on-chip input attenuators, including an external series input

protection resistor value between zero and 1 kΩ.

Total monitoring cycle time is nominally m × 755 µs + n × 33244 µs, where m is the number of channels conﬁgured as analog inputs, plus two for the internal V

measurement and internal temperature sensor, and n is the number of channels conﬁgured as external temperature channels (D1 and D2).

The total fan count is based on two pulses per revolution of the fan tachometer output.

Open-drain digital outputs may have an external pull-up resistor connected to a voltage lower or higher than V

(up to 6.5 V absolute maximum).

All logic inputs except ADD are tolerant of 5 V logic levels, even if V

is less than 5 V. ADD is a three-state input that may connected to V

, GND, or left open-circuit.

Timing speciﬁcations are tested at logic levels of V

= 0.8 V for a falling edge and V

= 2.2 V for a rising edge.

Speciﬁcations subject to change without notice.

HD;STA

SU;STA

SU;DAT

HIGH

HD;DAT

LOW

HD;STA

BUF

SCL

SDA

SU;STO

Figure 1. Diagram for Serial Bus Timing

Part #	ADM1024A
Description
Category	IC
Availability	In Stock
Qty	9

ADM1024A

Related Items

Technical Document