Window Comparator. LM77 Datasheet

LM77 Comparator. Datasheet pdf. Equivalent


etcTI LM77
LM77
www.ti.com
SNIS103F – JUNE 1999 – REVISED MARCH 2013
LM77 9-Bit + Sign Digital Temperature Sensor and Thermal Window Comparator with
Two-Wire Interface
Check for Samples: LM77
FEATURES
1
2 Window Comparison Simplifies Design of
ACPI Compatible Temperature Monitoring and
Control.
• Serial Bus Interface
• Separate Open-Drain Outputs for Interrupt and
Critical Temperature Shutdown
• Shutdown Mode to Minimize Power
Consumption
• Up to 4 LM77s Can be Connected to a Single
Bus
• 9-bit + Sign Output; Full-Scale Reading of Over
128°C
• SOIC and VSSOP 8-lead Packages
APPLICATIONS
• System Thermal Management
• Personal Computers
• Office Electronics
• Electronic Test Equipment
• Automotive
• HVAC
KEY SPECIFICATIONS
• Supply Voltage 3.0V to 5.5V
• Supply Current
– Operating
– 250 μA (typ)
– 500 μA (max)
– Shutdown
– 5 μA (typ)
• Temperature Accuracy
10°C to 65°C, ±1.5°C(max)
25°C to 100°C, ±2°C(max)
55°C to 125°C, ±3°C(max)
DESCRIPTION
The LM77 is a digital temperature sensor and thermal
window comparator with an I2C Serial Bus interface.
The window-comparator architecture of the LM77
eases the design of temperature control systems
conforming to the ACPI (Advanced Configuration and
Power Interface) specification for personal
computers. 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. The sensor
powers up with default thresholds of 2°C THYST, 10°C
TLOW, 64°C THIGH, and 80°C T_CRIT.
The LM77's 3.0V to 5.5V supply voltage range, Serial
Bus interface, 9-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, and HVAC applications.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 1999–2013, Texas Instruments Incorporated


LM77 Datasheet
Recommendation LM77 Datasheet
Part LM77
Description 9-Bit + Sign Digital Temperature Sensor and Thermal Window Comparator
Feature LM77; LM77 www.ti.com SNIS103F – JUNE 1999 – REVISED MARCH 2013 LM77 9-Bit + Sign Digital Temperature S.
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Datasheet
Download LM77 Datasheet




etcTI LM77
LM77
SNIS103F – JUNE 1999 – REVISED MARCH 2013
Simplified Block Diagram
www.ti.com
Connection Diagram
Figure 1.
Figure 2. SOIC-8 or VSSOP Package
See Package Number D0008A or DGK0008A
Pin Name
SDA
SCL
T_CRIT_A
Pin No.
1
2
3
PIN DESCRIPTIONS
Description
Serial Bi-Directional Data Line. Open Drain Output
Serial Bus Clock Input
Critical Temperature Alarm Open Drain Output
GND
INT
+VS
A0–A1
4 Power Supply Ground
5 Interrupt Open Drain Output
8 Positive Supply Voltage Input
7,6 User-Set Address Inputs
Typical Connection
From Controller
From Controller
Pull Up Resistor, Controller Interrupt Line or
System Hardware Shutdown
Ground
Pull Up Resistor, Controller Interrupt Line
DC Voltage from 3V to 5.5V
Ground (Low, “0”) or +VS (High, “1”)
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Copyright © 1999–2013, Texas Instruments Incorporated



etcTI LM77
www.ti.com
Typical Application
LM77
SNIS103F – JUNE 1999 – REVISED MARCH 2013
Figure 3. Typical Application
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings(1)
Supply Voltage
Voltage at any Pin
Input Current at any Pin
Package Input Current(2)
T_CRIT_A and INT Output Sink Current
T_CRIT_A and INT Output Voltage
Storage Temperature
Soldering Information, Lead Temperature
ESD Susceptibility(3)
Human Body Model
Machine Model
For soldering specifications: http://www.ti.com/lit/SNOA549(4)
0.3V to 6.5V
0.3V to (+VS + 0.3V )
5 mA
20 mA
10 mA
6.5V
65°C to +125°C
2500V
250V
(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.
(2) When the input voltage (VI) at any pin exceeds the power supplies (VI < GND or VI > +VS) the current at that pin should be limited to 5
mA. The 20 mA 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.
(3) Human body model, 100 pF discharged through a 1.5 kΩ resistor. Machine model, 200 pF discharged directly into each pin.
(4) Reflow temperature profiles are different for lead-free and non-lead-free packages.
Operating Ratings(1)(2)
Specified Temperature Range
See (3)
Supply Voltage Range (+VS)(4)
T MIN to TMAX
55°C to +125°C
+3.0V to +5.5V
(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.
(2) LM77 θJA (thermal resistance, junction-to-ambient) when attached to a printed circuit board with 2 oz. foil is: 200°C/W for the SOIC-8
(D0008A) package, 250°C/W for the VSSOP-8 (DGK0008A) package.
(3) While the LM77 has a full-scale-range in excess of 128°C, prolonged operation at temperatures above 125°C is not recommended.
(4) Both part numbers of the LM77 will operate properly over the +VS supply voltage range of 3V to 5.5V . The devices are tested and
specified for rated accuracy at their nominal supply voltage. Accuracy will typically degrade 1°C/V of variation in +VS as it varies from
the nominal value.
Copyright © 1999–2013, Texas Instruments Incorporated
Product Folder Links: LM77
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