# What does this Op Amp circuit do in this circuit for a line following robot?

I have seen a schematic for a line following robot, but there is something that I can't understand and is shown in the figure below, what is the purpose of the Op Amp circuit? I know that BREAK input in H-Bridge is independent on other pin. Could some one explain what this circuit does?

• note that the BREAK G is refer to BREAK D – Learner Dec 28 '13 at 18:04

The device that looks like an opamp is a comparator, it compares the REF_I_MAX input with ISENSE_G input. The output is low unless the sense level becomes higher than the reference voltage in which case the BRAKE_G output becomes high.