Trans-inductor voltage regulators with fault detection and the fault detection method thereof

A fault detection method used in a trans-inductor voltage regulator, the trans-inductor voltage regulator including a plurality of transformers, wherein each transformer of the plurality of transformers having a primary winding and a secondary winding, and wherein each secondary winding of each transformer of the plurality of transformers are coupled in series with a compensation inductor, and each primary winding of each transformer of the plurality of transformers is coupled to a switching circuit of a plurality of switching circuits, to serve as an output inductor of the switching circuit of the plurality of switching circuits, the method comprising:

• powering up each of the plurality of switching circuits one by one by firing a series of PWM pulses on one of the plurality of switching circuits and keeping other switching circuits idle during when a specific switching circuit of the plurality of switching circuits is powered up;
• detecting whether the switching circuit fired with the series of PWM pulses is powered up normally or whether there is a fault;
• reporting fault if a fault is detected;
• and
• powering up a next switching circuit if no fault is detected.

A fault detection method used in a trans-inductor voltage regulator, the trans-inductor voltage regulator including a plurality of transformers, wherein each transformer of the plurality of transformers having a primary winding and a secondary winding, and wherein each secondary winding of each transformer of the plurality of transformers are coupled in series with a compensation inductor, and each primary winding of each transformer of the plurality of transformers is coupled to a switching circuit of a plurality of switching circuits, the method comprising:

• providing a series of PWM pulses to fire any one switching circuit of the plurality of switching circuits, and pulling PWM signals provided to other switching circuits of the plurality of switching circuits to be low;
• comparing a current sense signal indicative of a current flowing through any one switching circuit of the plurality of switching circuits whose PWM signal is pulled low with a current threshold, to detect whether there is an open condition in a secondary side of the corresponding transformer;
• reporting fault if the open condition is detected;
• and
• ending the detection if no open condition is detected.