Tri-level capacitor structure in switched-capacitor filter
US5220483A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 16, 1992 |
| Grant date | Jun 15, 1993 |
| Priority date | — |
| Expiry date | Jan 16, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D1/68
Abstract
A tri-level capacitor structure includes a first shielded metal layer (36) that is disposed between an upper metal layer (38) and a lower polysilicon layer (34). The shielded metal layer (36) is separated from the polysilicon layer (34) by an oxide layer (42), and the upper metal layer (38) is separated from the shielded layer (36) by an oxide layer (44). The upper metal layer (38) and the polysilicon layer (34) are connected together to a node (48) to form an Insensitive Node, whereas the shielded layer (36) is connected to a node (46) that is referred to as the Sensitive Node (S). The capacitor structure is operable to be connected in a switched-capacitor configuration in a lossy integrator, such that the Sensitive Node is connected to the virtual ground of a differential amplifier (50). The integrator utilizing this configuration would be comprised of at least one switched-capacitor (56) on the input that has the plates thereof connected between ground and either an input signal V.sub.IN or the inverting input of the differential amplifier (50) through control switches (62) and (64). The Sensitive Node associated with node (46) is connected to the switch (62) such that it is con…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.