Patent ID: 8760898

Claim:
An apparatus addressing a potential transitory overshoot condition in a switch, the apparatus comprising: an inverter including a high-side switch coupled to a low-side switch, said inverter generating a time-varying drive current from a plurality of drive control signals, a positive rail voltage, and a negative rail voltage, wherein the apparatus has parasitic inductance, and wherein controlling the switches to generate said time-varying drive current produces a potential transitory overshoot condition for one of said switches of said inverter due to the parasitic inductance; a drive control, coupled to said inverter, to generate said drive control signals and to set a level of each of said rail voltages responsive to a plurality of controller signals; and a controller monitoring one or more parameters indicative of said potential transitory voltage overshoot condition, said controller dynamically adjusting, responsive to said monitored parameters, said controller signals to reduce a risk of occurrence of said potential transitory voltage overshoot condition; wherein said time-varying current includes a time-varying amplitude and wherein a DC link capacitance couples a positive rail voltage of said high-side switch with a negative rail voltage of said low-side switch and wherein said parameters include said time-varying amplitude and a voltage across said DC link capacitance and wherein said controller signals include a first series of high-side pulse width modulation (PWM) signals and a second series of low-side PWM signals for generation of said time-varying current and wherein said controller signals include a digital regulator signal to set said negative voltage rail at a second fixed regulated voltage in a range from about zero volts to less than said negative supply voltage despite the parasitic inductance in the apparatus.