I guess the MAX9634 can be used together with a comparator chip.
I just don't know how to interpret the data sheet correctly, mainly the gain expressed in units of 25V/V, 50V/V, 100V/V and 200V/V.
May be another member can shed some light on it.
The circuit should not contain more than a dozen parts including decoupling caps and resistors for the comparator chip (voltage divider etc.).
I just found the allegro-micro chip ACS713. It puts out 183mV/A using the 20A version. At 800mA the output voltage should be 145.6mv. Amplifying that voltage using an instrumentation amplifier such as INA111 you should get 5V at overcurrent.
Your software should be written a way to use a 10 second delay for overcurrent detection since the motor will presumely draw current of 4 times the nominal value (800mA) at start up.
Boncuk