General Description
The TC650/TC651 are integrated temperature sensors and brushless DC fan speed controllers. The TC650/TC651 measure their junction temperature and control the speed of the fan based on that temperature, making them especially suited for applications in modern electronic equipment.
Temperature data is converted from the on-chip thermal sensing element and translated into a fractional fan speed from 40% to 100%. A temperature selection guide in the data sheet is used to choose the low and high temperature limits to control the fan. The TC650/TC651 also include a single trip point over temperature alert (TOVER) that eliminates the need for additional temperature sensors. In addition, the TC651 features an auto fan shutdown function for additional power savings.
The TC650/TC651 are easy to use, require no software overhead and are therefore the ideal choice for implementing thermal management in a variety of systems.

Features
• Integrated Temperature Sensing and Multi-speed Fan Control
• Built-in Over Temperature Alert (TOVER)
• Temperature Proportional Fan Speed Control for
   Acoustic Noise Reduction and Longer Fan Life
• Pulse Width Modulation Output Drive for Cost and Power Savings
• Solid-State Temperature Sensing
• ±1°C (Typical) Accuracy from 25°C to +70°C
• 2.8V – 5.5V Operating Range
• TC651 includes Auto Fan Shutdown
• Low Operating Current: 50µA (Typical)

Applications
• Thermal Protection For Personal Computers
• Digital Set-Top Boxes
• Notebook Computers
• Data Communications
• Power Supplies
• Projectors