a clock management module that receives a system clock signal and a second clock signal, and that selects one of the system clock signal and the second clock signal as a selected clock signal;

a reference generating module that generates a reference signal;

a ramp generating module that receives the selected clock signal and that generates a ramp signal; and

a first pulse width modulation (PWM) module that receives the reference signal and the ramp signal, and that outputs a first PWM driver signal based on the reference signal and the ramp signal, wherein the selected clock signal is selected based on at least one of an inductance and a power dissipation of a hard disk drive.