I'm working on a dual H bridge for a bipolar stepper motor. I found these two designs. I would like to know which design would you guys recommend and why? and if there is any component that might be implemented to any of the designs to prevent any damage to the motor or to improve it's performance. The transistor that I will use are 2N7000, SUP90P06 and IRLZ44.The motor will be powered by a Lipo battery (11.1V, 25C, 2200mhA). The motor that I would be using has these characteristics:
Rated Voltage: 3.6V DC
Rated Current: 1.2A/phase
Winding Resistance: 8.8±10% ohms / phase
Winding Inductance: 3.5 mH±20 %( 1kHz 1V rms)
Holding torque: 185mN.m Min (Bipolar)
insulation resistance: 100Mohms Min (DC 500V)
and the second design is here, for this setup up I would add 100 ohms resistors for each of the inputs coming from the MCU to the gate pins. This design doesn't require the additional 2 N mosfets from the first design.