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AN1894 - APPLICATION NOTE

Waveforms look very similar to those presented for the buck converter. One should notice the negative

voltage present on the VIPer12 source after internal switch turn-off. The level of this negative voltage is

equal to the output voltage level.

3. CONCLUSION

A reference board with the monolithic switcher VIPer12AS was presented. The way, how the reference

board can be easily switched between two basic non-isolated topologies buck and buck-boost converter

was described. Depicted output regulation and overall converter efficiency characteristics measured at

different working conditions show good performance of this simple VIPer12AS application in such difficult

working environment. The circuit is EMI compliant (both emission and immunity), when a small input filter

is added.

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granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are

subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products

are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.

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