Herbert De Pauw

Comparative study on the effects of PVT variations between a novel all-MOS current reference and alternative CMOS solutions

Sensitivity to supply voltage, temperature and process variations of a number of current reference topologies and a novel circuit is compared in ON Semi I3T80 technology. The novel current reference shows the lowest process dependency, while supply and temperature dependency remain acceptably low.

Automatic load-based MOSFET segmentation for switching DC-DC converters

This paper proposes an automated approach for the optimization of the number of active segments in switching DC-DC converters with a segmented power stage. The drain-source voltage of the active power MOSFET segments is used to estimate the load current, and an automated segment controller activates an optimized number of segments. Using this approach automatically balances the switching loss and the conduction loss in the converter over the load range. The proposed concept is implemented in a prototype discrete 500 kHz boost converter, which confirms the optimized efficiency over the load range. Potential applications include high power discrete converters, where multiple power MOSFETs in parallel are already used and monolithically integrated converters, where the power MOSFET segments, drivers and control circuits are integrated on a single ASIC.

Introduction of a pseudo-6th ISDN splitter with bandstop topology

A newly developed ‘integrated services digital network’ (ISDN) splitter with bandstop (BS) topology is presented and compared to an actual ISDN splitter with a traditional low-pass (LP) topology. The LP-to-BS topology change reduced the amount of filter stages: a LP ISDN splitter requires an 8th order elliptic-like filter in order to be compliant to the standard ‘TS 101 952-1-4 V1.1.1’ [1] of the European Telecommunications Standards Institute (ETSI), whereas the BS ISDN splitter only needs a pseudo-6th order elliptic-like filter. The design of the new BS ISDN filter is discussed in the light of the enforced ETSI specifications. Furthermore, both the ISDN splitters are compared in the field of their specific stopband performance and their physical implementation. The area reduction that comes together with the introduction of the new ISDN splitter with BS topology is more than 25%.