National Semiconductor LM95221 Technical data

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LM95221 Dual Remote Diode Digital Temperature Sensor with SMBus Interface

General Description

The LM95221 is a dual remote diode temperature sensor in an 8-lead MSOP package. The 2-wire serial interface of the LM95221 is compatible with SMBus 2.0. The LM95221 can sense three temperature zones, it can measure the temperature of its own die as well as two diode connected transistors. The diode connected transistors can be a thermal diode as found in Pentium and AMD processors or can simply be a diode connected MMBT3904 transistor. The LM95221 resolution format for remote temperature readings can be programmed to be 10-bits plus sign or 11-bits unsigned. In the unsigned mode the LM95221 remote diode readings can resolve temperatures above 127˚C. Local temperature readings have a resolution of 9-bits plus sign.

The temperature of any ASIC can be accurately determined using the LM95221 as long as a dedicated diode (semiconductor junction) is available on the target die. The LM95221 remote sensor accuracy of series resistance of 2.7 ohms and 1.008 non-ideality factor.

±

1˚C is factory trimmed for a

Features

n Accurately senses die temperature of remote ICs or

diode junctions

n Remote diode fault detection n On-board local temperature sensing n Remote temperature readings:

— 0.125 ˚C LSb — 10-bits plus sign or 11-bits programmable resolution

— 11-bits resolves temperatures above 127 ˚C

n Local temperature readings:

— 0.25 ˚C — 9-bits plus sign

n Status register support n Programmable conversion rate allows user optimization

of power consumption

n Shutdown mode one-shot conversion control n SMBus 2.0 compatible interface, supports TIMEOUT n 8-pin MSOP package

Key Specifications

j

Local Temperature Accuracy

T

=0˚C to 85˚C±3.0 ˚C (max)

A

j

Remote Diode Temperature Accuracy

T

=30˚C to 50˚C, TD=45˚C to 85˚C±1.0 ˚C (max)

A

T

=0˚C to 85˚C, TD=25˚C to 140˚C±3.0 ˚C (max)

A

j

Supply Voltage 3.0 V to 3.6 V

j

Supply Current 2 mA (typ)

Applications

n Processor/Computer System Thermal Management

(e.g. Laptop, Desktop, Workstations, Server)

n Electronic Test Equipment n Office Electronics

LM95221 Dual Remote Diode Digital Temperature Sensor with SMBus Interface

May 2004

Simplified Block Diagram

20094301

Pentium™is a trademark of Intel Corporation.

Connection Diagram

LM95221

MSOP-8

20094302

TOP VIEW

Ordering Information

Part Number

LM95221CIMM LM95221CIMM MUA08A (MSOP-8) 1000 Units on Tape

LM95221CIMMX LM95221CIMM MUA08A (MSOP-8) 3500 Units on Tape

Package

Marking

NS Package

Number

Pin Descriptions

Label Pin # Function Typical Connection

D1+ 1 Diode Current Source To Diode Anode. Connected to remote discrete

diode-connected transistor junction or to the diode-connected transistor junction on a remote IC whose die temperature is being sensed. A 2.2 nF diode bypass capacitor is recommended to filter high frequency noise. Place the 2.2 nF capacitor between and as close as possible to the LM95221’s D+ and D− pins. Make sure the traces to the 2.2 nF capacitor are matched. Ground this pin if this thermal diode is not used.

D1− 2 Diode Return Current Sink To Diode Cathode. A 2.2 nF capacitor is

recommended between D1+ and D1-. Ground this pin if this thermal diode is not used.

D2+ 3 Diode Current Source To Diode Anode. Connected to remote discrete

diode-connected transistor junction or to the diode-connected transistor junction on a remote IC whose die temperature is being sensed. A 2.2 nF diode bypass capacitor is recommended to filter high frequency noise. Place the 2.2 nF capacitor between and as close as possible to the LM95221’s D+ and D− pins. Make sure the traces to the 2.2 nF capacitor are matched. Ground this pin if this thermal diode is not used.

D2− 4 Diode Return Current Sink To Diode Cathode. A 2.2 nF capacitor is

recommended between D2+ and D2-. Ground this pin if this thermal diode is not used.

GND 5 Power Supply Ground Ground

V

DD

6 Positive Supply Voltage

Input

DC Voltage from 3.0 V to 3.6 V. VDDshould be bypassed with a 0.1 µF capacitor in parallel with 100 pF. The 100 pF capacitor should be placed as close as possible to the power supply pin. Noise should be kept below 200 mVp-p, a 10 µF capacitor may be required to achieve this.

Transport

Media

and Reel

SMBus Device

Address

010 1011

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Pin Descriptions (Continued)

Label Pin # Function Typical Connection

SMBDAT 7 SMBus Bi-Directional Data

Line, Open-Drain Output

SMBCLK 8 SMBus Clock Input From Controller; may require an external pull-up

From and to Controller; may require an external pull-up resistor

resistor

Typical Application

LM95221

20094303

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Absolute Maximum Ratings (Note 1)

Supply Voltage −0.3 V to 6.0 V

LM95221

Voltage at SMBDAT, SMBCLK −0.5V to 6.0V

Voltage at Other Pins −0.3 V to (V

D− Input Current

Input Current at All Other Pins (Note 2)

Package Input Current (Note 2) 30 mA

SMBDAT Output Sink Current 10 mA

Storage Temperature −65˚C to +150˚C

Soldering Information, Lead Temperature

MSOP-8 Package (Note 3)

Vapor Phase (60 seconds) 215˚C

DD

+ 0.3 V)

±

1mA

±

5mA

Infrared (15 seconds) 220˚C

ESD Susceptibility (Note 4)

Human Body Model 2000 V

Machine Model 200 V

Operating Ratings

(Notes 1, 5)

Operating Temperature Range 0˚C to +115˚C

Electrical Characteristics Temperature Range T

LM95221CIMM 0˚C≤TA≤+85˚C

Supply Voltage Range (V

) +3.0V to +3.6V

DD

MIN≤TA≤TMAX

Temperature-to-Digital Converter Characteristics

Unless otherwise noted, these specifications apply for VDD=+3.0Vdc to 3.6Vdc. Boldface limits apply for TA=TJ= T

MIN≤TA≤TMAX

junction temperature of the remote thermal diode.

Accuracy Using Local Diode T

Accuracy Using Remote Diode, see (Note 9) for Thermal Diode Processor Type.

Remote Diode Measurement Resolution 11 Bits

Local Diode Measurement Resolution 10 Bits

Conversion Time of All Temperatures at the Fastest Setting

Quiescent Current (Note 10) SMBus Inactive, 15Hz conversion

D− Source Voltage 0.7 V

Diode Source Current (D+ − D−)=+ 0.65V; high-level 188 315 µA (max)

Low-Level Diode Source Current Variation over Temperature

Power-On Reset Threshold Measure on V

; all other limits TA=TJ=+25˚C, unless otherwise noted. TJis the junction temperature of the LM95221. TDis the

Parameter Conditions Typical Limits Units

(Note 6) (Note 7) (Limit)

= 0˚C to +85˚C, (Note 8)

A

T

= +30˚C to

A

+50˚C

= +0˚C to

T

A

+85˚C

TD= +45˚C to +85˚C

TD= +25˚C to +140˚C

±

1

±

3 ˚C (max)

±

1 ˚C (max)

±

3 ˚C (max)

0.125 ˚C

0.25 ˚C

(Note 11) 66 73 ms (max)

2.0 2.6 mA (max)

rate

Shutdown 335 µA

110 µA (min)

Low-level 11.75 20 µA (max)

7 µA (min)

T

= +30˚C to +50˚C +0.5 µA

A

T

= +30˚C to +85˚C +1.5 µA

A

edge

input, falling

DD

2.4

1.8

V (max)

V (min)

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Logic Electrical Characteristics

DIGITAL DC CHARACTERISTICS Unless otherwise noted, these specifications apply for VDD=+3.0 to 3.6 Vdc. Boldface limits apply for T

A=TJ=TMIN

to T

Symbol Parameter Conditions Typical Limits Units

SMBDAT, SMBCLK INPUTS

V

IN(1)

V

IN(0)

V

IN(HYST)

Logical “1” Input Voltage 2.1 V (min)

Logical “0”Input Voltage 0.8 V (max)

SMBDAT and SMBCLK Digital Input Hysteresis

I

C

IN(1)

IN(0)

IN

Logical “1” Input Current VIN=V

Logical “0” Input Current VIN= 0 V −0.005

Input Capacitance 5 pF

SMBDAT OUTPUT

I

OH

V

OL

High Level Output Current VOH=V

SMBus Low Level Output Voltage IOL= 4mA

SMBus DIGITAL SWITCHING CHARACTERISTICS Unless otherwise noted, these specifications apply for VDD=+3.0 Vdc to +3.6 Vdc, C

(load capacitance) on output lines = 80 pF. Boldface limits apply for TA=TJ=T

L

=TJ= +25˚C, unless otherwise noted. The switching characteristics of the LM95221 fully meet or exceed the published specifications of the SMBus version 2.0. The following parameters are the timing relationships between SMBCLK and SMBDAT signals related to the LM95221. They adhere to but are not necessarily the SMBus bus specifications.

Symbol Parameter Conditions Typical Limits Units

f

t

HIGH

t

R,SMB

t

F,SMB

t

TIMEOUT

SMBus Clock Frequency 100

SMB

SMBus Clock Low Time from V

LOW

SMBus Clock High Time from V

SMBus Rise Time (Note 12) 1 µs (max)

SMBus Fall Time (Note 13) 0.3 µs (max)

t

Output Fall Time CL= 400pF,

OF

SMBDAT and SMBCLK Time Low for Reset of Serial Interface (Note 14)

t

SU;DAT

t

HD;DAT

t

HD;STA

Data In Setup Time to SMBCLK High 250 ns (min)

Data Out Stable after SMBCLK Low 300

Start Condition SMBDAT Low to SMBCLK Low (Start condition hold before the first clock falling edge)

t

SU;STO

Stop Condition SMBCLK High to SMBDAT Low (Stop Condition Setup)

t

SU;STA

SMBus Repeated Start-Condition Setup Time, SMBCLK High to SMBDAT Low

t

SMBus Free Time Between Stop and Start

BUF

Conditions

; all other limits TA=TJ=+25˚C, unless otherwise noted.

MAX

(Note 6) (Note 7) (Limit)

400 mV

0.005

max 4.7

IN(0)

min 4.0 µs (min)

IN(1)

I

OL

DD

= 6mA

IN(0)

IN(1)

= 3mA, (Note 13)

I

O

max to V

min to V

±

10 µA (max)

±

10 µA (max)

0.4

V (max)

0.6

MIN

to T

; all other limits T

MAX

(Note 6) (Note 7) (Limit)

kHz (max)

10

kHz (min)

µs (min)

25

ms (max)

250 ns (max)

25 35

ms (min)

ms (max)

ns (min)

900

ns (max)

100 ns (min)

0.6 µs (min)

1.3 µs (min)

LM95221

A

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