L6227Q, Non-dissipative over current protection, how to implement.

[Peter Fournier]

In the manual for the L6227Q, Section 4.6 (page 16) it talks about Non-dissipative over current protection. It says the external current sense resistor can be eliminated, I assume I should replace the sensing resistors with a short, but I tried that with the demo board and it would not run. Removing the short allowed it to start. I don't really need current control but OCD is good.

-Pete

[Enrico Poli]

Hi Peter,

The overcurrent protection of the L6227Q is implemented sensing the current flowing into the high side MOSFETs: when it is above the internal threshold (2.8 A typ) the EN pin is forced low disabling the power stage (the details are in the datasheet).

I confirm that in this case the sensing resistor is not needed and you can short the SENSEX pins directly to the ground, however you should keep the VREF input of the PWM current controller at an higher voltage.

If you do not need the PWM current controller of the L6227Q, I suggest you to try the L6226Q.