AN2829

Test setup and performance summary

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Figure 8.

REF, LDO5 and LDO power-up

11.3

Soft-start and shutdown waveforms

Figure 9, 10, 11 and 12 show, respectively, the soft-start and shutdown waveforms.

The PM681A has an independent internal digital soft-start for each switching section.

During the soft-start phase the internal current limit increases from 25% to 100% with steps

of 25% to avoid the inductor current rising abruptly.

AM01414v1