CONVERTISSEUR ANALOGIQUE-NUMERIQUE ET NUMERIQUE-ANALOGIQUE C-2C

A C-2C analog-to digital and digital-to-analog converter is described, the C-2C designation referring to the arrangement of capacitance in a capacitor ladder network. The capacitors are formed in a monolithic, multilayer structure which includes a substrate, diffusion regions in the substrate, a polysilicon layer and an aluminum layer wherein the capacitances are formed between the aluminum layer and the polysilicon layer and between the polysilicon layer and the diffusion region, and these capacitances have the ratio of 2C to C respectively. The capacitor ladder network formed in the multilayer structure can be trimmed or adjusted electrically after manufacture to obtain the desired tolerances.