This paper presents two power devices architectures designed for 20V and 10V power management switching applications, respectively, the separated drain MOSFET one and the drain extension MOSFET. Global losses are evaluated through R/sub on/*C/sub gg/ figure of merit. Electrical results bring forward the dummy gated separated drain MOSFET for 20V application and confirm the drain extension MOSFET as a serious competitor for 10V applications.

A novel dynamic gate capacitance characterization technique is proposed to evaluate switching losses in power devices. Dynamic gate capacitance is obtained by measuring the gate displacement current due to the application of a controlled gate voltage pulse, closely matching real operation conditions of power switches. Several architectures for 20-V MOSFET transistors, integrated in a low-cost power management 0.13-/spl mu/m CMOS technology, are studied. Experimental results are compared to a specific small-signal model for switching transition gate capacitance.

Switching performances of low-cost 20V drift-MOSFETs and diffused-MOSFETs power devices are compared. Thanks to a new dynamic gate capacitance measurement protocol, the average gate capacitance responsible for power losses during fast switching transitions is estimated and the Miller effect contribution is quantified. Optimized drift-MOSFETs with reduced gate length and gate to drain overlap present comparable and even better performances than diffused-MOSFETs. Moreover they present the lowest process over-cost, making them excellent and very competitive candidates for low-cost portable power management applications