User`s guide

Software Design

FIGURE 3-6: ZVT PHASE-SHIFT CONVERTER

Current sensing for the Phase-Shift ZVT Converter uses two dedicated analog inputs

to measure the primary transformer current in both directions. The two analog inputs

are tied to the same current signal, but are sampled at opposite current peaks. The

precise triggering instants are in Figure 3-7 along with the expected current waveform.

The current in the positive and negative directions must be measured and checked for

any imbalance. If the currents in the two directions are not balanced, it may cause a

phenomenon called “flux walking” in the ZVT transformer. Flux walking must be

prevented since it may lead to transformer saturation and subsequent damage to the

system hardware.

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