Rainbow Electronics LM92 User Manual

March 2000

LM92

±

0.33˚C Accurate, 12-Bit + Sign Temperature Sensor and

Thermal Window Comparator with Two-Wire Interface

LM92

Two-Wire Interface

±

0.33˚C Accurate, 12-Bit + Sign Temperature Sensor and Thermal Window Comparator with

General Description

The LM92 is a digital temperature sensor and thermal win­dow comparator with an I
accuracy of
of the LM92 eases the design of temperature control sys­tems. The open-drain Interrupt (INT) output becomes active
whenever temperature goes outside a programmable win­dow, while a separate Critical Temperature Alarm
(T_CRIT_A) output becomes active when the temperature
exceeds a programmable critical limit. The INT output can
operate in either a comparator or event mode, while the
T_CRIT_A output operates in comparator mode only.

The host can program both the upper and lower limits of the
window as well as the critical temperature limit. Program­mable hysterisis as well as a fault queue are available to
minimize false tripping. Two pins (A0, A1) are available for
address selection.Thesensorpowers up with default thresh­olds of 2˚C T
T_CRIT.

The LM92’s 2.7V to 5.5V supply voltage range, Serial Bus in­terface, 12-bit + sign output, and full-scale range of over
128˚C make it ideal for a wide range of applications. These
include thermal management and protection applications in
personal computers, electronic test equipment, office elec­tronics, automotive, medical and HVAC applications.

±

0.33˚C. The window-comparator architecture

HYST

2

C™Serial Bus interface and an

, 10˚C T

LOW

, 64˚C T

, and 80˚C

HIGH

Features

n Window comparison simplifies design of ACPI

compatible temperature monitoring and control.

n Serial Bus interface
n Separate open-drain outputs for Interrupt and Critical

Temperature shutdown

n Shutdown mode to minimize power consumption
n Up to 4 LM92s can be connected to a single bus
n 12-bit + sign output
n Operation up to 150˚C

Key Specifications

j

Supply Voltage 2.7V to 5.5V

j

Supply Current operating 350µA (typ)

625µA (max)

shutdown 5µA (typ)

j

Temperature 30˚C±0.33˚C(max)

Accuracy 10˚C to 50˚C

−10˚C to 85˚C
125˚C

−25˚C to 150˚C

j

Linearity

j

Resolution 0.0625˚C

±

0.50˚C(max)

±

1.0˚C(max)

±

1.25˚C(max)

±

1.5˚C(max)

±

0.5˚C(max)

Applications

n HVAC
n Medical Electronics
n Electronic Test Equipment
n System Thermal Management
n Personal Computers
n Office Electronics
n Automotive

Simplified Block Diagram

DS101051-1

I2C®is a registered trademark of Philips Corporation.

© 2000 National Semiconductor Corporation DS101051 www.national.com

Connection Diagram

LM92

Ordering Information

Pin Descriptions

SO-8

DS101051-2

LM92

See NS Package Number M08A

Order Number Supply Voltage Supplied As

LM92CIM 2.7V to 5.5V
LM92CIMX 2.7V to 5.5V 2500 Units on Tape and Reel

Label Pin

SDA 1 Serial Bi-Directional Data Line. Open Drain Output From Controller
SCL 2 Serial Bus Clock Input From Controller
T_CRIT_A 3 Critical Temperature Alarm Open Drain Output Pull Up Resistor, Controller Interrupt Line

GND 4 Power Supply Ground Ground
INT 5 Interrupt Open Drain Output Pull Up Resistor, Controller Interrupt Line
+V

S

A0–A1 7,6 User-Set Address Inputs Ground (Low, “0”) or +V

#

8 Positive Supply Voltage Input DC Voltage from 2.7V to 5.5V

Function Typical Connection

or System Hardware Shutdown

(High, “1”)

S

Typical Application

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DS101051-3

LM92

Absolute Maximum Ratings (Note 1)

Soldering Information, Lead
Temperature

Supply Voltage −0.3 V to 6.5V
Voltage at any Pin −0.3 V

to (+V

+ 0.3V)

S

Input Current at any Pin 5mA
Package Input Current (Note 2) 20mA
T_CRIT_A and INT Output Sink

Current 10mA

SOP and MSOP Package (Note 3)

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

ESD Susceptibility (Note 4)

Human Body Model 2500V
Machine Model 250V

T_CRIT_A and INT Output
Voltage 6.5V

Storage Temperature −65˚C to +125˚C

Operating Ratings(Notes 1, 5)

Specified Temperature Range T

MIN

to T
(Note 6) −55˚C to +150˚C
Supply Voltage Range (+V

) +2.7V to +5.5V

S

Electrical Characteristics

Temperature-to-Digital Converter CharacteristicsUnless otherwise noted, these specifications apply for +VS=+2.7V to +5.5V
for LM92CIM . Boldface limits apply for TA=TJ=T

Parameter Conditions

Accuracy (This is a summary. For
more detailed information please
see (Note 9))

= +30˚C, +VS= 3.3V to

T

A

4.0V
T

= 10˚C or +50˚C, +VS=

A

3.3V to 4.0V
T

= −10 ˚C or +85˚C, +VS=

A

3.3V to 4.0V
T

= +125˚C, +VS= 4.0V

A

T

= −25˚C to 150˚C, +VS=

A

4.0V

Resolution (Note 10) 13

Linearity (Note 11)
Offset Error of Transfer Function

+V

= 4.0V ˚C (max)

S

(Note 12)
Offset Error of Transfer Function

Supply Sensitivity

2.7V ≤ +V

3.6V ≤ +V

<

S

≤ 5.5V ˚C/V (max)

S

Temperature Conversion Time (Note 13) 500 1000 ms
Quiescent Current I

2

C Inactive 0.35 mA

2

I

C Active 0.35 0.625 mA (max)

Shutdown Mode 5 µA

T

Default Temperature (Notes 15, 16) 2 ˚C

HYST

T

Default Temperature (Note 16) 10 ˚C

LOW

T

Default Temperature (Note 16) 64 ˚C

HIGH

T

Default Temperature (Note 16) 80 ˚C

C

MIN

to T

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

MAX

Typical

(Note 7)

Limits

(Note 8)

±

0.33

±

0.50

±

1.00

±

1.25

±

1.50

Units

(Limit)

˚C (max)

Bits

0.0625

±

0.5 ˚C (max)

˚C

3.6V ˚C/V (max)

MAX

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Electrical Characteristics

LM92

DIGITAL DC CHARACTERISTICSUnless otherwise noted, these specifications apply for +VS=+2.7V to +5.5V for LM92CIM .
Boldface limits apply for TA=TJ=T

Symbol Parameter Conditions

V

IN(1)

SDA and SCL Logical “1” Input

MIN

to T

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

MAX

Typical

(Note 7)

Limits

(Note 8)

+VSx 0.7 V (min)

Voltage

+V

+0.3 V (max)

S

V

IN(0)

SDA and SCL Logical “0” Input

−0.3 V (min)

Voltage

+V

x 0.3 V (max)

S

V

IN(HYST)

SDA and SCL Digital Input

500 250 mV (min)

Hysteresis

V

IN(1)

A0 and A1 Logical “1” Input

2.0 V (min)

Voltage

+V

+0.3 V (max)

S

V

IN(0)

A0 and A1 Logical “0” Input

−0.3 V (min)

Voltage

0.7 V (max)
I
I
C
I
V

IN(1)
IN(0)

IN

OH

OL

Logical “1” Input Current VIN=+V

S

0.005 1.0 µA (max)
Logical “0” Input Current VIN= 0 V −0.005 −1.0 µA (max)
Capacitance of All Digital Inputs 20 pF
High Level Output Current VOH=+V

S

10 µA (max)
Low Level Output Voltage IOL=3mA 0.4 V (max)
T_CRIT_A Output Saturation

Voltage

I

= 4.0 mA

OUT

(Note 14)

0.8 V (max)

T_CRIT_A Delay 1 Conversions

t

OF

Output Fall Time CL= 400 pF 250 ns (max)

I

=3mA

O

SERIAL BUS DIGITAL SWITCHING CHARACTERISTICS Unless otherwise noted, these specifications apply for +VS=+2.7V
to +5.5V for LM92CIM . Boldface limits apply for TA=TJ=T
noted. CL (load capacitance) on output lines = 80 pF unless otherwise specified. Boldface limits apply for T
T

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

MAX

The switching characteristics of the LM92 fully meet or exceed the published specifications of the I

MIN

to T

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

MAX

2

A=TJ=TMIN

C bus. The following pa­rameters are the timing relationship between SCL and SDA signal related to the LM92. They are not the I2C bus specifica­tions.

Symbol Parameter Conditions

t

1

SCL (Clock) Period 2.5 µs(min)

Typical

(Note 7)

Limits

(Note 8)

1 ms(max)

t

2

t

3

t

4

t

5

t

TIMEOUT

Data in Set-Up Time to SCL High 100 ns(min)
Data Out Stable after SCL Low 0 ns(min)
SDA Low Set-Up Time to SCL Low (Start Condition) 100 ns(min)
SDA High Hold Time after SCL High (Stop Condition) 100 ns(min)
SDA and SCL Time Low for Reset of Serial Interface

(Note 17)

75

300

Units

(Limit)

(max)

to

Units

(Limit)

ms (min)

ms

(max)

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Electrical Characteristics (Continued)

Serial Bus Communication

DS101051-4

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not apply when operating
the device beyond its rated operating conditions.

Note 2: When the input voltage (V
maximum package input current rating limits the number of pins that can safely exceed the power supplies with an input current of 5 mA to four.

Note 3: See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” or the section titled “Surface Mount” found in a current National Semicon­ductor Linear Data Book for other methods of soldering surface mount devices.

Note 4: Human body model, 100 pF discharged through a 1.5 kΩ resistor. Machine model, 200 pF discharged directly into each pin.
Note 5: LM92 θ
Note 6: While the LM92 has a full-scale-range in excess of 128 ˚C, prolonged operation at temperatures above 125 ˚C is not recommended.
Note 7: Typicals are at T
Note 8: Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).

(thermal resistance, junction-to-ambient) when attached to a printed circuit board with 2 oz. foil is 200 ˚C/W.

JA

) at any pin exceeds the power supplies (V

I

= 25 ˚C and represent most likely parametric norm.

A

<

I

GND or V

>

+VS) the current at that pin should be limited to 5 mA. The 20 mA

I

LM92

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Electrical Characteristics (Continued)

LM92

Note 9: The limits found in the following table supersede the limits shown in the Electrical Characteristics Table.The Accuracy specification includes errors due to

linearity,offset and gain. The accuracy specification includes effects of self heating with negligible digital output loading. Pull-up resistors should be maximized (10k
typical recommended), so that self heating due to digital output loading is negligible.

Temperature Accuracy Parameter Limits Units

Conditions +V

T

= −25˚C −1.35/+1.50 −1.25/+1.50 −1.25/+1.50 −1.05/+1.70 −1.05/+1.80 ˚C (max)

A

T

= −10˚C

A

T

= 0˚C −0.80/+0.75 −0.70/+0.75 −0.70/+0.75 −0.50/+0.95 −0.50/+1.05 ˚C (max)

A

T

= 10˚C −0.60/+0.50

A

T

= 30˚C −0.43/+0.33

A

T

= 50˚C −0.60/+0.50

A

T

= 85˚C −1.10/+0.85 −1.00/+0.85 −1.00/+0.85 −0.80/+1.05 −0.80/+1.15 ˚C (max)

A

T

= 125˚C −1.60/+1.25 −1.50/+1.25

A

T

= 150˚C

A

Limits at intermediate temperatures can be calculated using a straight line interpolation as shown in the following graphs:

=2.7V +VS=3.3V +VS=4V +VS=5V +VS=5.5V

S

±

1.00 −0.90/+1.00 −0.90/+1.00 −0.70/+1.20 −0.70/+1.30 ˚C (max)

±

0.50

±

0.33

±

0.50

±

1.90 −1.75/+1.50

±

0.50 −0.30/+0.70 −0.30/+0.80 ˚C (max)

±

0.33 −0.13/+0.53 −0.13/+0.63 ˚C (max)

±

0.50 −0.30/+0.70 −0.30/+0.80 ˚C (max)

±

1.25 −1.05/+1.45 −1.05/+1.55 ˚C (max)

±

1.50 −1.30/+1.70 −1.30/+1.80 ˚C (max)

Accuracy vs Temperature with +Vs=5V

Accuracy vs Temperature with +Vs= 3.3V

Note 10: 12 bits + sign, two’s complement

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DS101051-20

DS101051-21