ON Semiconductor ADM1032 Technical data

1C Remote and Local

System Temperature Monitor

FEATURES On-Chip and Remote Temperature Sensing Offset Registers for System Calibration

0.125C Resolution/1C Accuracy on Remote Channel 1C Resolution/3C Accuracy on Local Channel Fast (Up to 64 Measurements per Second) 2-Wire SMBus Serial Interface Supports SMBus Alert Programmable Under/Overtemperature Limits Programmable Fault Queue Overtemperature Fail-Safe THERM Output Programmable THERM Limits Programmable THERM Hysteresis 170 A Operating Current

5.5 A Standby Current 3 V to 5.5 V Supply Small 8-Lead SOIC and MSOP Packages

APPLICATIONS Desktop and Notebook Computers Smart Batteries Industrial Controllers Telecommunications Equipment Instrumentation Embedded Systems

FUNCTIONAL BLOCK DIAGRAM

ON-CHIP

TEMPERATURE

SENSOR

D+

ANALOG

D–

MUX

BUSY

EXTERNAL DIODE OPEN-CIRCUIT

ADM1032

A/D

CONVERTER

RUN/STANDBY

LOCAL TEMPERATURE

VALUE REGISTER

REMOTE TEMPERATURE

VALUE REGISTER

REMOTE OFFSET

ADM1032

PRODUCT DESCRIPTION

The ADM1032 is a dual-channel digital thermometer and under/ overtemperature alarm intended for use in personal computers and thermal management systems. The higher 1∞C accuracy offered allows systems designers to safely reduce temperature guardbanding and increase system performance. The device can measure the temperature of a microprocessor using a diode-connected NPN or PNP transistor, which may be provided on-chip or can be a low cost discrete device, such as the 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 ADM1032 communicates over a 2-wire serial interface compatible with System Management Bus (SMBus) standards. Under and overtemperature limits can be programmed into the device over the serial bus, and an ALERT output signals when the on-chip or remote temperature measurement is out of range.

output can be used as an interrupt or as an SMBus alert.

This The THERM output is a comparator output that allows CPU clock throttling or on/off control of a cooling fan. An ADM1032-1

available. The only difference between the ADM1032 and the

is ADM1032-1 is the default value of the external

An ADM1032-2 is also available. It has a different SMBus address to the ADM1032 and the ADM1032-1. The SMBus address of the ADM1032-2 is 0x4D.

ADDRESS POINTER

CONVERSION RATE

LOCAL TEMPERATURE

LOW LIMIT REGISTER

LOCAL TEMPERATURE

HIGH LIMIT REGISTER

COMPARATOR

DIGITAL MUX

STATUS REGISTER

LIMIT

DIGITAL MUX

SMBUS INTERFACE

REMOTE TEMPERATURE

LOW LIMIT REGISTER

REMOTE TEMPERATURE

HIGH LIMIT REGISTER

LOCAL THERM LIMIT

EXTERNAL THERM LIMIT

CONFIGURATION

INTERRUPT

MASKING

THERM

ALERT

THERM

limit.

GND

REV. D

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 registered trademarks are the property of their respective owners.

SDATA

*Patents 5,982,221, 6,097,239, 6,133,753, 6,169,442, 5,867,012.

SCLK

ADM1032–SPECIFICATIONS

Parameter Min Typ Max Unit Test Conditions/Comments

POWER SUPPLY

Supply Voltage, V Average Operating Supply Current, I

Undervoltage Lockout Threshold 2.35 2.55 2.8 V V Power-On Reset Threshold 1 2.4 V

TEMPERATURE-TO-DIGITAL CONVERTER

Local Sensor Accuracy ± 1 ± 3 ∞C0 £ T Resolution 1 ∞C Remote Diode Sensor Accuracy ± 1 ∞C60∞C £ T

Resolution 0.125 ∞C Remote Sensor Source Current 230 mAHigh Level

Conversion Time 35.7 142.8 ms From Stop Bit to Conversion Complete

OPEN-DRAIN DIGITAL OUTPUTS (THERM, ALERT)

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

SERIAL BUS TIMING

Logic Input High Voltage, V

SCLK, SDATA

Logic Input Low Voltage, V

Hysteresis 500 mV SCLK, SDATA SDATA Output Low Sink Current 6 mA SDATA Forced to 0.6 V ALERT Output Low Sink Current 1 mA ALERT Forced to 0.4 V Logic Input Current, I

, I

Input Capacitance, SCLK, SDATA 5 pF Clock Frequency 400 kHz SMBus Timeout 25 64 ms See Note 3 SCLK Clock Low Time, t SCLK Clock High Time, t Start Condition Setup Time, t Start Condition Hold Time, t

Stop Condition Setup Time, t

LOW

HIGH

SU:STA

HD:STA

SU:STO

Data Valid to SCLK Rising Edge 100 ns Time for 10% or 90% of SDATA to

Time, t Data Hold Time, t Bus Free Time, t SCLK, SDATA Rise Time, t SCLK, SDATA Fall Time, t

NOTES

See Table VI for information on other conversion rates.

Guaranteed by design, not production tested.

The SMBus timeout is a programmable feature. By default, it is not enabled. Details on how to enable it are available in the Serial Bus Interface section of this data sheet.

Specifications subject to change without notice.

SU:DAT

HD:DAT

BUF

3.0 3.30 5.5 V 170 215 mA 0.0625 Conversions/Sec Rate

5.5 10 mA Standby Mode

Input, Disables ADC, Rising Edge

£ 100∞C, VCC = 3 V to 3.6 V

± 3 ∞C0∞C £ T

13 mALow Level

£ 120∞C

(Both Channels) One-Shot Mode with Averaging Switched On

5.7 22.8 ms One-Shot Mode with Averaging Off

(i.e., Conversion Rate = 32 or 64 Conversions per Second)

0.4 V I

0.1 1 mAV

= –6.0 mA

OUT

= V

OUT

2.1 V VDD = 3 V to 5.5 V

0.8 V VDD = 3 V to 5.5 V

–1 +1 mA

1.3 mst

0.6 mst

between 10% Points

LOW

between 90% Points

HIGH

600 ns 600 ns Time from 10% of SDATA to 90%

of SCLK

600 ns Time from 90% of SCLK to 10%

of SDATA

10% of SCLK

300 ns

1.3 msBetween Start/Stop Condition

300 ns 300 ns

REV. D–2–

ADM1032

ABSOLUTE MAXIMUM RATINGS*

Positive Supply Voltage (V

D+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to V

) to GND . . . . . . –0.3 V, +5.5 V

+ 0.3 V

D– to GND . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +0.6 V

SCLK, SDATA, ALERT . . . . . . . . . . . . . . . . –0.3 V to +5.5 V

THERM . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to V

+ 0.3 V

THERMAL CHARACTERISTICS

8-Lead SOIC Package

= 121∞C/W

8-Lead MSOP Package

= 142∞C/W

Input Current, SDATA, THERM . . . . . . . . –1 mA, +50 mA

Input Current, D– . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 1 mA

ESD Rating, All Pins (Human Body Model) . . . . . . >1,000 V

Maximum Junction Temperature (T

max) . . . . . . . . . 150∞C

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

IR Reflow Peak Temperature . . . . . . . . . . . . . . . . . . . . 220∞C

IR Reflow Peak Temperature for Pb-Free . . . . . . . . . . 260∞C

Lead Temp (Soldering 10 sec) . . . . . . . . . . . . . . . . . . . 300∞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.

ORDERING GUIDE

Temperature Package Package SMBus External

Model Range Description Option Branding Addr Default

ADM1032AR 0∞C to 120∞C 8-Lead SOIC R-8 1032AR 4C 85⬚C ADM1032AR-REEL 0∞C to 120∞C 8-Lead SOIC R-8 1032AR 4C 85⬚C ADM1032AR-REEL7 0∞C to 120∞C 8-Lead SOIC R-8 1032AR 4C 85⬚C ADM1032ARZ ADM1032ARZ-REEL ADM1032ARZ-REEL7

0∞C to 120∞C 0∞C to 120∞C 8-Lead SOIC R-8 1032AR 4C 85⬚C

0∞C to 120∞C 8-Lead SOIC R-8 1032AR 4C 85⬚C

8-Lead

SOIC R-8 1032AR 4C 85⬚C

ADM1032AR-1 0∞C to 120∞C 8-Lead SOIC R-8 1032AR01 4C 108⬚C ADM1032AR-1REEL 0∞C to 120∞C 8-Lead SOIC R-8 1032AR01 4C 108⬚C ADM1032AR-1REEL7 0∞C to 120∞C 8-Lead SOIC R-8 1032AR01 4C 108⬚C ADM1032ARZ-1 ADM1032ARZ-1REEL ADM1032ARZ-1REEL7 ADM1032ARM ADM1032ARM-REEL 0∞C to 120∞C 8-Lead ADM1032ARM-REEL7 0∞C to 120∞C 8-Lead ADM1032ARMZ ADM1032ARMZ-REEL ADM1032ARMZ-REEL7 ADM1032ARM-1

0∞C to 120∞C 8-Lead SOIC R-8 1032AR 4C 85⬚C

0∞C to 120∞C 8-Lead SOIC R-8 1032AR 4C 85⬚C 0∞C to 120∞C

0∞C to 120∞C

0∞C to 120∞C 8-Lead MSOP RM-8 T2A 4C 85⬚C

0∞C to 120∞C 8-Lead MSOP RM-8 T2A 4C 85⬚C 0∞C to 120∞C

8-Lead MSOP

MSOP MSOP

8-Lead MSOP

RM-8 T2A 4C 85⬚C RM-8 T2A 4C 85⬚C RM-8 T2A 4C 85⬚C RM-8 T2A 4C 85⬚C

RM-8 T1A 4C 108⬚C ADM1032ARM-1REEL 0∞C to 120∞C 8-Lead MSOP RM-8 T1A 4C 108⬚C ADM1032ARM-1REEL7 0∞C to 120∞C 8-Lead MSOP RM-8 T1A 4C 108⬚C ADM1032ARMZ-1 ADM1032ARMZ-1REEL ADM1032ARMZ-1REEL7 ADM1032ARMZ-2 ADM1032ARMZ-2REEL

0∞C to 120∞C

0∞C to 120∞C 8-Lead MSOP RM-8 T1A 4C 108⬚C

0∞C to 120∞C 8-Lead MSOP RM-8 T1A 4C 108⬚C 0∞C to 120∞C 8-Lead MSOP RM-8 T1C 4D 85⬚C

0∞C to 120∞C 8-Lead MSOP RM-8 T1C 4D 85⬚C

8-Lead MSOP

RM-8 T1A 4C 108⬚C

ADM1032ARMZ-2REEL710∞C to 120∞C 8-Lead MSOP RM-8 T1C 4D 85⬚C

Z = Pb-free part.

THERM

REV. D

SCLK

SDATA

BUF

HD:STA

LOW

HD:DAT

HIGH

SU:DAT

Figure 1. Diagram for Serial Bus Timing

–3–

HD:STA

SU:STA

SU:STO

ADM1032

PIN CONFIGURATION

THERM

D+

D–

ADM1032

TOP VIEW

(Not to Scale)

SCLK

SDATA

ALERT

GND

PIN FUNCTION DESCRIPTIONS

Pin No. Mnemonic Description

Positive Supply, 3 V to 5.5 V. 2D+Positive Connection to Remote Temperature Sensor. 3D–Negative Connection to Remote Temperature Sensor. 4 THERM THERM is an open-drain output that can be used to turn a fan on/off or throttle a CPU clock in the event of

an overtemperature condition. Requires pull-up to V

5GND Supply Ground Connection. 6 ALERT Open-Drain Logic Output Used as Interrupt or SMBus Alert. 7 SDATA Logic Input/Output, SMBus Serial Data. Open-drain output. Requires pull-up resistor. 8 SCLK Logic Input, SMBus Serial Clock. Requires pull-up resistor.

REV. D–4–

Typical Performance Characteristics–ADM1032

–4

–8

TEMPERATURE ERROR – C

–12

–16

010100

D+ TO GND

D+ TO V

LEAKAGE RESISTANCE – M

TPC 1. Temperature Error vs. Leakage Resistance

= 250mV p-p

= 100mV p-p

TEMPERATURE ERROR – C

10 1M

FREQUENCY – Hz

1.0

0.5

TEMPERATURE ERROR – C

–0.5

020406080100 120

TEMPERATURE – C

TPC 2. Temperature Error vs. Actual Temperature Using 2N3906

TEMPERATURE ERROR – C

161116 21 26 31

CAPACITANCE – nF

TEMPERATURE ERROR – C

–1

100k 100M1M

= 40mV p-p

= 10mV p-p

FREQUENCY – Hz

10M

TPC 3. Temperature Error vs. Differential Mode Noise Frequency

2.0

1.5

1.0

= 5V

0.5

SUPPLY CURRENT – A

0.01

VDD = 3V

0.1 1 10 100 CONVERSION RATE – Hz

TPC 4. Temperature Error vs. Power Supply Noise Frequency

TEMPERATURE ERROR – C

0 100k 1M 10M 100M

VIN = 100mV p-p

VIN = 50mV p-p

VIN = 25mV p-p

FREQUENCY – Hz

TPC 7. Temperature Error vs.

Common-Mode Noise Frequency

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

SUPPLY CURRENT – A

151025 50 75 100

SCLK FREQUENCY – kHz

DD =

3.3V

DD =

250 500 750 1000

TPC 8. Standby Supply Current vs. Clock Frequency

TPC 6. Operating Supply Current vs. Conversion Rate

STANDBY SUPPLY CURRENT – A

1.5 2.50.5 1.0 3.0 5.03.5 4.0 4.52.0

SUPPLY VOLTAGE – V

TPC 9. Standby Supply Current vs. Supply Voltage

REV. D

–5–

ADM1032

FUNCTIONAL DESCRIPTION

The ADM1032 is a local and remote temperature sensor and overtemperature alarm. When the ADM1032 is operating normally, the on-board A/D converter operates in a freerunning mode. The analog input multiplexer alternately selects either the on-chip temperature sensor to measure its local temperature or the remote temperature sensor. These signals are digitized by the ADC and the results are stored in the Local and Remote Temperature Value Registers.

The measurement results are compared with local and remote, high, low, and THERM temperature limits stored in nine onchip registers. Out-of-limit comparisons generate flags that are stored in the Status Register, and one or more out-of limit results will cause the ALERT output to pull low. Exceeding THERM temperature limits causes the THERM output to assert low.

The limit registers can be programmed, and the device controlled and configured, via the Serial System Management Bus (SMBus). The contents of any register can also be read back via the SMBus.

Control and configuration functions consist of

∑

Switching the device between normal operation and standby mode.

∑

Masking or enabling the ALERT output.

∑

Selecting the conversion rate.

MEASUREMENT METHOD

A simple method of measuring temperature is to exploit the negative temperature coefficient of a diode, or the base-emitter voltage of a transistor, operated at constant current. Unfortunately, this technique requires calibration to null out the effect of the absolute value of V

, which varies from device to device.

The technique used in the ADM1032 is to measure the change in V

when the device is operated at two different currents.

This is given by

Figure 2 shows the input signal conditioning used to measure the output of an external temperature sensor. This figure shows the external sensor as a substrate transistor, provided for temperature monitoring on some microprocessors, but it could equally well be a discrete transistor. If a discrete transistor is used, the collector will not be grounded and should be linked to the base. To prevent ground noise interfering with the measurement, the more negative terminal of the sensor is not referenced to ground but is biased above ground by an internal diode at the D– input. If the sensor is operating in a noisy environment, C1 may optionally be added as a noise filter. Its value is typically 2,200 pF but should be no more than 3,000 pF. See the section on Layout Considerations for more information on C1.

To measure DV

, the sensor is switched between the operating

currents of I and N ¥ I. The resulting waveform is passed through a 65 kHz low-pass filter to remove noise, and then to a chopper-stabilized amplifier that performs the functions of amplification and rectification of the waveform to produce a dc voltage proportional to DV

. This voltage is measured by the

ADC to give a temperature output in twos complement format. To further reduce the effects of noise, digital filtering is performed by averaging the results of 16 measurement cycles.

Signal conditioning and measurement of the internal temperature sensor is performed in a similar manner.

TEMPERATURE DATA FORMAT

One LSB of the ADC corresponds to 0.125∞C, so the ADC can measure from 0∞C to 127.875∞C. The temperature data format is shown in Tables I and II.

The results of the local and remote temperature measurements are stored in the Local and Remote Temperature Value Registers and are compared with limits programmed into the Local and Remote High and Low Limit Registers.

Table I. Temperature Data Format (Local Temperature and Remote Temperature High Byte)

DVn

BE f

where:

K is Boltzmann’s constant (1.38 ¥ 10 q is the charge on the electron (1.6 ¥ 10

()¥()

In N

–23

–19

Coulombs).

T is the absolute temperature in Kelvins. N is the ratio of the two currents. n

is the ideality factor of the thermal diode.

The ADM1032 is trimmed for an ideality factor of 1.008.

IN  I I

D+

REMOTE SENSING

TRANSISTOR

C1*

D–

CAPACITOR C1 IS OPTIONAL AND IT SHOULD ONLY BE USED IN VERY NOISY ENVIRONMENTS. C1 = 1000pF MAX.

BIAS

DIODE

Figure 2. Input Signal Conditioning

BIAS

LOW-PASS FILTER

= 65kHz

Temperature Digital Output

0∞C0000 0000 1∞C0000 0001 10∞C0000 1010 25∞C0001 1001 50∞C0011 0010 75∞C0100 1011 100∞C0110 0100 125∞C0111 1101 127∞C0111 1111

OUT+

TO ADC

OUT–

REV. D–6–

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