National Semiconductor LM64 Remote Diode Temperature Sensor Datasheet

The LM64 temperature sensor has ±1˚C remote diode temperature accuracy with PWM fan control and 5 GPIO

Brand: National Semiconductor
Category: Other Electronics
Document type: Datasheet
Language: English
Pages: 29
File format: PDF
File size: 377 KB
Published: 07 April, 2012
Updated: 30 September, 2023
MD5 checksum: D5290809EF42A71035904278A3DAC7A5
PDF: National Semiconductor LM64 Remote Diode Temperature Sensor Datasheet PDF

About this manual

The LM64 remote diode temperature sensor measures its own temperature and that of a connected diode, providing accurate readings with a factory‑trimmed ±1.0 °C error for remote diodes. It includes an open‑drain PWM fan control output and five general‑purpose I/O pins for flexible system integration.

The device operates from a 3.0 V to 36 V supply, draws 1.4 mA typical current, and communicates via an SMBus 2.0‑compatible interface. Detailed pin descriptions, electrical characteristics, and layout guidelines are provided for designers.

What's inside

General Description
Key Specifications
Power Supply Requirements
Pin Descriptions
Simplified Block Diagram
Ordering Information
Typical Application
Absolute Maximum Ratings
DC Electrical Characteristics
AC Electrical Characteristics

Specifications

Supply Voltage Range	3.0 V to 36 V
Typical Supply Current	1.4 mA
SMBus Compatibility	SMBus 2.0 compatible interface
Fan Control Accuracy	±10 % (max)

Frequently asked questions

What is the supply voltage range for the LM64?

The LM64 operates from 3.0 V up to 36 V.

What is the maximum fan control accuracy of the LM64?

Fan control accuracy is specified as ±10 % (max).

How is the SMBus address selected on the LM64?

Pin 12 (AO) selects the SMBus address: high sets 0x4E, low sets 0x18.

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