Switching amplifier and method for estimating remaining lifetime of a switching amplifier

A method for estimating a remaining lifetime of a switching amplifier that comprises a power device, the power device configured for powering a load and comprised of a plurality of switches, wherein each of the plurality of switches is coupled in parallel with a diode;

• the method comprising:
• calculating a switch junction temperature for a bonding wire in each switch based at least in part on a power loss of the switch;
• generating a first accumulated fatigue damage of the bonding wire in each switch based on the switch junction temperature;
• calculating a case temperature for a solder layer in each of the plurality of switches based on an average value of the power loss of each switch and a power loss of the corresponding diode;
• generating an accumulated fatigue damage of the solder layer in each switch based on the case temperature;
• and
• generating an estimated remaining lifetime of the switching amplifier based on at least one of the first accumulated fatigue damages of the bonding wires in each switch and the accumulated fatigue damages of the solder layers in each switch.

A gradient amplifier, comprising:

• a power device comprising a plurality of bridge circuits coupled in series between two terminals of a gradient coil and each comprised of a plurality of switches;
• and a processing device configured to:
• calculate a switch junction temperature for a bonding wire in each of the plurality of switches based at least in part on a power loss of each switch;
• generate a first accumulated fatigue damage of the bonding wire in each switch based on the switch junction temperature;
• and
• generate an estimated remaining lifetime of the switching amplifier based on the first accumulated fatigue damages of the bonding wires in each switch.