1 Features
1• Built-In Lock Detection and Rotational Speed
Sensing Mechanisms
• Compact 8-Pin Package Reduces Number of
External Components Required
• Automatic Restart When Motor Lock Is Undone
• Hall Amplifier Inputs Have Hysteresis

2 Applications
Small Server Fans

3 Description
The TMP821 device is a two-phase half-wave motor
predriver that is suited for fan motors, which has
winding in push-pull configuration. It uses differential
hall effect sensors for commutation signals for two of
the switches in power circuit. The device has a very
small pin count, making it very simple to use.