Rainbow Electronics LM83 User Manual

November 1999

LM83
Triple-Diode Input and Local Digital Temperature Sensor
with Two-Wire Interface

LM83 Triple-Diode Input and Local Digital Temperature Sensor with Two-Wire Interface

General Description

The LM83 is a digital temperature sensor with a 2 wire serial
interface thatsensesthe voltage and thus the temperature of
three remote diodes using a Delta-Sigma analog-to-digital
converter with a digital over-temperature detector.The LM83
accurately senses its own temperature as well as the tem­perature of three external devices, such as Pentium II
cessors or diode connected 2N3904s. The temperature of
anyASIC can be detected using the LM83 as long as a dedi­cated diode (semiconductor junction) is available on the die.
Using the SMBus interface a host can access the LM83’s
registers at any time. Activation of a T_CRIT_A output oc­curs when any temperature is greater than a programmable
comparator limit, T_CRIT. Activation of an INT output occurs
when any temperature is greater than its corresponding pro­grammable comparator HIGH limit.

The host can program as well as read back the state of the
T_CRIT register and the four T_HIGH registers. Three state
logic inputs allow two pins (ADD0, ADD1) to select up to 9
SMBus address locations for the LM83. The sensor powers
up with default thresholds of 127˚C for T_CRIT and all
T_HIGHs. The LM83 is pin for pin and register compatible
with the LM84 as well as the Maxim MAX1617 and the Ana­log Devices ADM1021.

®

Pro-

Features

n Accurately senses die temperature of 3 remote ICs, or

diode junctions

n On-board local temperature sensing
n SMBus and I

SMBus 1.1 TIMEOUT

n Two interrupt outputs: INT and T_CRIT_A
n Register readback capability
n 7 bit plus sign temperature data format, 1 ˚C resolution
n 2 address select pins allow connection of 9 LM83s on a

single bus

2

C compatible interface, supports

Key Specifications

j

Supply Voltage 3.0V to 3.6V

j

Supply Current 0.8mA (max)

j

Local Temp Accuracy (includes quantization error)

0˚C to +85˚C

j

Remote Diode Temp Accuracy (includes quantization

error)

+25˚C to +100˚C

0˚C to +125˚C

±

3.0˚C (max)

±

3˚C (max)

±

4˚C (max)

Applications

n System Thermal Management
n Computers
n Electronic Test Equipment
n Office Electronics
n HVAC

Simplified Block Diagram

DS101058-1

SMBus™is a trademark of the Intel Corporation.

®

Pentium II

is a registered trademark of the Intel Corporation.

®

I2C

is a registered trademark of the Philips Corporation.

© 2000 National Semiconductor Corporation DS101058 www.national.com

Connection Diagram Ordering Information

LM83

QSOP-16

DS101058-2

TOP VIEW

Order

Number

LM83CIMQA

LM83CIMQAX

Typical Application

NS

Package

Number

MQA16A

(QSOP-16)

MQA16A

(QSOP-16)

Transport

Media

95 Units in

Rail

2500 Units on
Tape and
Reel

Pin Description

Label Pin

D1+, D2+, D3+ 1, 3, 5

V

CC

www.national.com 2

#

Diode Current Source To Diode Anode. Connected to remote discrete

2

Positive Supply Voltage
Input

Function Typical Connection

DS101058-3

diode junction or to the diode junction on a remote
IC whose die temperature is being sensed. When
not used they should be left floating.

DC Voltage from 3.0 V to 3.6 V

Pin Description (Continued)

LM83

Label Pin

D− 4

ADD0–ADD1 10, 6

#

Function Typical Connection

Diode Return Current
Sink

2

User-Set SMBus (I

C)

Address Inputs

GND 7, 8 Power Supply Ground Ground

Manufacturing test pins. Left floating. PC board traces may be routed

NC 9, 13, 15

INT

11

SMBData 12

Interrupt Output,
open-drain

SMBus (I

2

C) Serial
Bi-Directional Data Line,
open-drain output

2

SMBCLK 14 SMBus (I

T_CRIT_A

16

Critical Temperature
Alarm, open-drain output

C) Clock Input From Controller, Pull-Up Resistor

To all Diode Junction Cathodes using a star
connection to pin. Must float when not used.

Ground (Low, “0”), VCC(High, “1”) or open
(“TRI-LEVEL”)

through the pads for these pins, although the
components that drive these traces should share
the same supply as the LM83 so that the Absolute
Maximum Rating, Voltage at Any Pin, is not
violated.

Pull Up Resistor, Controller Interrupt or Alert Line

From and to Controller, Pull-Up Resistor

Pull Up Resistor, Controller Interrupt Line or
System Shutdown

www.national.com3

Absolute Maximum Ratings (Note 1)

LM83

Supply Voltage −0.3 V to 6.0 V
Voltage at Any Pin −0.3 V to

D− Input Current
Input Current at All Other Pins (Note

(V

CC

+ 0.3 V)

±

1mA

QSOP Package (Note 3)

Vapor Phase (60 seconds) 215˚C
Infrared (15 seconds) 220˚C

ESD Susceptibility (Note 4)

Human Body Model 2000 V
Machine Model 200 V

2) 5 mA
Package Input Current (Note 2) 20 mA
SMBData, T_CRIT_A, INT Output

Sink Current 10 mA
SMBCLK, SMBData, T_CRIT_A, INT

Output Voltage 6.0 V
Storage Temperature −65˚C to +150˚C

Operating Ratings

(Notes 1, 5)
Specified Temperature Range T

LM83 −40˚C to +125˚C
Supply Voltage Range (V

) +3.0V to +3.6V

CC

Soldering Information, Lead Temperature

Temperature-to-Digital Converter Characteristics

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

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

MAX

Parameter Conditions Typical Limits Units

(Note 6) (Note 7) (Limit)

Temperature Error using Local
Diode ((Note 8))

Temperature Error using Remote
Diode ((Note 8))

T

= 0 ˚C to +85˚C,

A

=+3.3V

V

CC

T

= −40 ˚C to +125˚C,

A

=+3.3V

V

CC

T

= +60 ˚C to +100˚C,

A

=+3.3V

V

CC

T

= 25 ˚C to +100˚C,

A

=+3.3V

V

CC

T

= 0 ˚C to +125˚C,

A

=+3.3V

V

CC

±

1

Diode Channel to Channel Matching 0 ˚C
Resolution 8 Bits

1˚C

Conversion Time of All

(Note 10) 460 600 ms (max)

Temperatures
Quiescent Current (Note 9) SMBus (I

2

C) Inactive 0.500 0.80 mA (max)
D− Source Voltage 0.7 V
Diode Source Current (D+ − D−)=+ 0.65V; high

level
Low level 15 µA (max)

T_CRIT_A and INT Output

I

= 3.0 mA 0.4

OUT

Saturation Voltage
Power-On Reset Threshold On V

input, falling

CC

edge

Local and Remote T_CRIT and

(Note 11) +127 ˚C

HIGH Default Temperature settings

±

3 ˚C (max)

±

4 ˚C (max)

±

3

±

3 ˚C (max)

±

4 ˚C (max)

125 µA (max)

60 µA (min)

5 µA (min)

2.3

1.8

to T

MIN

˚C (max)

V (max)
V (max)

V (min)

MIN

MAX

to

www.national.com 4

Logic Electrical Characteristics

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

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

MAX

Symbol Parameter Conditions Typical Limits Units

(Note 6) (Note 7) (Limit)

SMBData, SMBCLK

V
V

IN(1)
IN(0)

V

IN(HYST)

Logical “1” Input Voltage 2.1 V (min)
Logical “0”Input Voltage 0.8 V (max)
SMBData and SMBCLK Digital

300 mV

Input Hysteresis
I
I

IN(1)
IN(0)

Logical “1” Input Current VIN=V

CC

0.005 1.5 µA (max)

Logical “0” Input Current VIN= 0 V −0.005 1.5 µA (max)

ADD0, ADD1

V
V
I
I

IN(1)

IN(0)
IN(1)
IN(0)

Logical “1” Input Voltage V

CC

1.5 V (min)
Logical “0”Input Voltage GND 0.6 V (max)
Logical “1” Input Current VIN=V

CC

2 µA (max)

Logical “0” Input Current VIN=0V -2 µA (max)

ALL DIGITAL INPUTS

C

IN

Input Capacitance 20 pF

ALL DIGITAL OUTPUTS

I

OH

V

OL

High Level Output Current VOH=V
SMBus Low Level Output

Voltage

IOL=3mA

=6mA

I

OL

CC

100 µA (max)

0.4

0.6

MIN

V (max)

LM83

to

www.national.com5

Logic Electrical Characteristics (Continued)

LM83

SMBus DIGITAL SWITCHING CHARACTERISTICS

Unless otherwise noted, these specifications apply for VCC=+3.0 Vdc to +3.6 Vdc, CL(load capacitance) on output lines = 80
pF. Boldface limits apply for T
The switching characteristics of the LM83 fully meet or exceed the published specifications of the SMBus or I2C bus. The fol­lowing parameters are the timing relationships between SMBCLK and SMBData signals related to the LM83. They are not the

2

I

C or SMBus bus specifications.

A=TJ=TMIN

to T

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

MAX

Symbol Parameter Conditions Typical Limits Units

(Note 6) (Note 7) (Limit)

f

SMB

SMBus Clock Frequency 100

10

t

LOW

SMBus Clock Low Time 10 % to 10 % 1.3

25

t

MEXT Cumulative Clock Low Extend Time 10 ms (max)

LOW

t

HIGH

t

R,SMB

t

F,SMB

t

OF

t

TIMEOUT

t

1

t

,

2

t

SU;DAT

t

,

3

t

HD;DAT

t

,

4

t

HD;STA

t

,

5

t

SU;STO

t

,

6

t

SU;STA

t

BUF

SMBus Clock High Time 90 % to 90% 0.6 µs (min)
SMBus Rise Time 10% to 90% 1 µs (max)
SMBus Fall Time 90% to 10% 0.3 ns (max)
Output Fall Time CL= 400 pF,

=3mA

I

O

SMBData and SMBCLK Time Low for
Reset of Serial Interface (Note 12)

250 ns (max)

25
40

SMBCLK (Clock) Period 10 µs (min)
Data In Setup Time to SMBCLK High 100 ns (min)

Data Out Stable after SMBCLK Low 300

TBD

SMBData Low Setup Time to SMBCLK

100 ns (min)

Low
SMBData High Delay Time after

100 ns (min)

SMBCLK High (Stop Condition Setup)
SMBus Start-Condition Setup Time 0.6 µs (min)

SMBus Free Time 1.3 µs (min)

kHz (max)

kHz (min)

µs (min)

ms (max)

ms (min)

ms (max)

ns (min)

ns (max)

SMBus Communication

www.national.com 6

DS101058-4