Burn-in system power stage

A burn-in system for stress testing integrated circuits, the system comprising:

• a testing stage configured to stress test an integrated circuit;
• and
• a power stage comprising:
• a pulse width modulator configured to generate a modulated power output that is coupled to the testing stage;
• a current control circuit comprising:
• a measured load current coupled to a first input, wherein the measured load current is indicative of a current supplied to the testing stage by the modulate power output;
• a target load current coupled to a second input;
• and
• a current error output signal that is generated based on a voltage difference between the first and second inputs;
• and
• a voltage control circuit comprising:
• a measured load voltage coupled to a first input, wherein the measured load voltage is indicative of the load voltage that is being supplied to the testing stage;
• a second input coupled to the current error output signal;
• a target voltage coupled to the second input;
• and
• a voltage error output signal that is generated based on a voltage difference between the first and second inputs of the voltage control circuit
• wherein the modulated power output is generated based on the voltage error output signal.

In a burn-in system, a method of controlling power supplied to an integrated circuit testing stage comprising:

• providing a modulated power output from a pulse width modulator to a load of the testing stage;
• receiving a measured load current, which is indicative of a current supplied to the testing stage by the modulated power output;
• receiving a target load current;
• receiving a measured load voltage, which is indicative of a voltage across the load, at a first input of a voltage control circuit;
• receiving a target load voltage at a second input of a voltage control circuit;
• receiving a current error output signal, which is based on a difference between the measured load current and the target load current, at one of the first and second inputs of the voltage control circuit;
• generating a voltage error output signal based on a voltage difference between the first and second inputs;
• and
• controlling the modulated power output based on the voltage error output signal.