Authors: C.C. McAndrew
Affilation: Freescale Semiconductor, United States
Pages: 745 - 748
Keywords: MOSFET modeling, SPICE modeling, MOSFET symmetry
Symmetry around Vds=0 is a critical requirement for<br>MOSFET models, e.g. as it affects the ability of a model to<br>simulate accurately distortion for some RF CMOS mixers.<br>The Gummel Symmetry Test is, until now, the standard<br>test used to evaluate the symmetry of MOSFET models.<br>However, this test is only applicable to DC current,<br>and is only applicable when there is negligible<br>gate or substrate current. This paper presents a<br>modified DC symmetry test that is applicable in the<br>presence of gate and substrate currents, and a new<br>AC symmetry test that is simple and effective in<br>verifying symmetry of gate to source and drain capacitance.<br>It is easily extensible to test other capacitance coefficient<br>symmetries.