Capacitor structure and capacitor array

Abstract

The invention provides a capacitor structure and a capacitor array. The capacitor structure comprises an upper pole plate and a lower pole plate, wherein the upper pole plate comprises a main upper pole plate and a secondary upper pole plate; the main upper pole plate is connected with a common end; the secondary upper pole plate is grounded; the main upper pole plate and the lower pole plate form a main capacitor; and the secondary upper pole plate and the lower pole plate form a secondary capacitor. The main upper pole plate and the secondary upper pole plate are arranged in the capacitor structure, the corresponding main capacitor participates charge redistribution, the secondary capacitor does not participate charge redistribution, and the capacitance value of the main capacitor can be changed by amending the area of the main upper pole plate, so that the capacitor structure has different fractional ratio capacitance values; and moreover, the sum of the area of the main upper pole plate and the area of the secondary upper pole plate in each capacitor structure is equal when the capacitor structure is used, so that the problem of capacitor mismatching existing when a plurality of capacitor structures with different capacitance values are used can be solved.

Description

technical field [0001] The invention belongs to the technical field of analog integrated circuits, and in particular relates to a capacitor structure and a capacitor array. Background technique [0002] As one of the commonly used ADC (Analog-to-Digital Converter, analog-to-digital converter) structure types, SAR (Successive-Approximation-Register, successive approximation register) ADC is obtained due to its simple structure, easy integration, and low power consumption. widely used. However, with the reduction of integrated circuit design technology and process feature size, the scale of SOC (System-on-a-Chip, system-on-a-chip) is getting larger and larger, and the chip area and performance of the ADC embedded in it have been raised. strict requirements. [0003] Capacitor array is an important part of SAR ADC, its linearity and voltage coefficient directly affect the performance of SAR ADC, and its area directly affects the overall chip area of ​​SAR ADC. At present, th...

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Problems solved by technology

[0004] The present invention provides a capacitor structure to solve the problem of capacitance mismatch when using multiple capacitor structures with different capacitance values; in addition, the present invention also provides a capacitor array to solve the problem that the capacitor array occupies too much area in SARADC. big problem

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