Controlling Vehicle Door Mirrors with Current Sensing Diagnostics Included

DC motor drivers serve a variety of functions in modern automobile designs, both internally (engine valve control or seat positioning) and externally. Mirror movement is among the most common external ones.  

Toshiba has an informative video demonstrating how motorised control, based on its automotive-grade TB9051 motor driver, may be used to open and fold up a vehicle door mirror. Using a single-channel H-bridge with integrated MOSFETs, the TB9051 device can deliver up to 5A and 28V to an attached motor. Pulse-width modulated (PWM) signals enable forward, reverse and brake modes to be applied.

The high-side current sensing capability means the output may be monitored in real time. From this, it can be shown when the mirror reaches one of its endpoints, or if there is an obstruction preventing its smooth motion. This real-time high-side current monitoring feature will be useful in a multitude of other scenarios - with the potential for motor angle to be determined, as well as the identification of load open and motor blocking issues. 

A new window will open