To operate in voltage mode, there are a three main issues that need to be addressed. The first is that as the motor speeds up, back EMF reduces the effective voltage driving the coil and therefore the current goes down, reducing the motor torque. Back EMF compensation in the L6470 will be discussed in this presentation. Another issue is that variations in the power supply voltage directly affect the current. The L6470 overcomes this supply voltage issue with voltage compensation. The third major drawback is that as the motor heats up, the winding resistance increases and the motor current is reduced. The resistance compensation register on the L6470 can address this issue.