Some applications require stall detection to notify the microcontroller of a locked rotor condition. A stall could be caused by one of two things: unintended mechanical blockage or the load reaching an end-stop in a constrained travel path. By using current-sense amplifier (CSA) to amplify the voltage on the ISEN pin of the DRV8231, the system can implement a simple stall detection scheme. Figure 9-6 shows an example schematic implementation.

The principle of this stall detection scheme relies on the fact that motor current increases during stall conditions as shown in Figure 9-7. To implement stall detection, the microcontroller reads the voltage from CSA using an analog-to-digital converter (ADC) and compares it to a stall threshold set in firmware. Alternatively, a comparator peripheral may be used to set this threshold as well.