If you are looking to drive two high-power motors through one compact unit, these dual VNH2SP30 motor driver carriers are perfect for you. With these boards, it’s easy to get a medium-sized, differential drive robot running in no time.
Need to drive some serious current to a set of motors? The compact Pololu MD03A motor driver is designed for some serious power requirements!
Based on the ST Electronics VNH2SP30 motor driver IC, the MD01B offers current sensing, reverse battery protection, and 20kHz PWM frequency operation.
The dual motor driver PCB includes can mount up to three large capacitors for power filtration. Two 10mm radial capacitors may be mounted between the motor driver ICs, and an axial capacitor may be mounted between the ICs and power connections. You don't generally need all three, and two radial capacitors are included with each unit. For applications that require a low profile, a single capacitor can be installed on its side.
|MOSFET on-resistance (per leg)||19 mΩ|
|Maximum PWM frequency||20 kHz|
|Current sense output||approximately 0.13 volts per amp|
|Over-voltage shutoff||could be as low as 16 V (19 V typical)|
|Time to overheat at 20 A*||35 seconds|
|Time to overheat at 15 A*||150 seconds|
|Current for infinite run time*||14 A|
*Typical results with 100% duty cycle at room temperature.
This motor driver has a 30A maximum current rating, but can overheat at lower current levels. For maximum power transfer, you will have to keep the motor driver cool with a heat sink or fan. Tests show that we were able to deliver short durations (on the order of milliseconds) of 30 A and several seconds of 20 A without overheating. At 6 A, the chips gets just barely noticeably warm to the touch. For high-current installations, the motor and power supply wires should also be soldered directly instead of going through the supplied terminal blocks, which are rated for up to 15 A.
Unlike other motor controllers that have a "surge" rating, these motor drivers have over-current protection that can kick-in at levels between 30 and 45A. Don't count on being able to exceed 30A, but with the 30A continuous current rating, that is something you should not have a problem with!
The motor driver boards include an N-channel MOSFET for reverse-battery protection. This component keeps the motor driver from destroying itself if the input power is accidentally connected backwards. However, this component does slightly increase the total resistance between your battery and your motor. For slightly improved performance, the MOSFET can be bypassed by connecting the negative battery terminal to the bypass pin. (This terminal will also need to be connected to your logic supply ground).