A small area DAC capacitor array for SAR type ADC
A capacitor array and small-area technology, applied in electrical components, electrical signal transmission systems, signal transmission systems, etc., can solve problems such as low area utilization, extremely sensitive process parameters, abrupt layout, etc., and achieve small DAC area and layout design Compact, low-cost effect
Active Publication Date: 2017-11-10
上海菱沃铂智能技术有限公司
View PDF6 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
In order to control the accuracy, it is usually necessary to add capacitance DUMMY around Cs and Cx, so that the layout of this circuit between stages is usually abrupt, the area utilization rate is low, and the actual manufacturing accuracy is not good, which limits the resolution of small-area DACs. rate increase, while being extremely sensitive to process parameters
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment
[0032] Such as Figure 6-9 Said, a small-area DAC capacitor array for SAR ADC, the DAC capacitor array corresponds to the C-2C ladder capacitor network circuit, and is formed by a plurality of repeating units horizontally and compactly arranged;
[0033] Each repeating unit includes a bit capacitance C n , parasitic capacitance C p , Interstage capacitance C s and interstage parallel capacitance C x ; The parasitic capacitance C p with bit capacitance C n Common anode, cathode grounded;
[0034] The interstage parallel capacitor C x and interstage capacitance C s After parallel connection, one end is connected with bit capacitance C n The anode is connected, and the other end is connected to the bit capacitance C of the adjacent side repeating unit n anode connection; the bit capacitance C n between and interstage capacitance C s There is a lateral parasitic capacitance Cx between them 0 ; The bit capacitance C n between and interstage capacitance C s There is a ...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention relates to a small-area DAC capacitor array for an SAR type ADC. The DAC capacitor array corresponds to a C-2C ladder resistance network circuit and is composed of multiple repetitive units horizontally distributed in a compact mode. Each repetitive unit comprises a bit capacitor Cn, a parasitic capacitor Cp, an inter-pole capacitor Cs and an inter-pole shunt capacitor Cx, wherein the parasitic capacitor Cp and the bit capacitor Cn share an anode, the cathode of the parasitic capacitor Cp and the cathode of the bit capacitor Cn are grounded, one end of the inter-pole shunt capacitor Cx is connected with the anode of the bit capacitor Cn after the inter-pole shunt capacitor Cx and the inter-pole capacitor Cs are connected in parallel, and the other end of the inter-pole shunt capacitor Cx is connected with the anode of the bit capacitor Cn of the adjacent repetitive unit. Transverse parasitic capacitors Cx0 are arranged between the bit capacitors Cn and between the inter-pole capacitors Cs, and longitudinal parasitic capacitors Cp0 are arranged between the bit capacitors Cn and between the inter-pole capacitors Cs. Compared with the prior art, the small-area DAC capacitor array has the advantages of being high in resolution ratio, small in area, high in utilization rate and the like.
Description
technical field [0001] The invention relates to a DAC capacitor array, in particular to a small-area DAC capacitor array for SAR ADC. Background technique [0002] A SAR (Successive Approximation Register) type ADC (Analog to Digital Converter) is a common integrated circuit ADC structure for moderate to high resolution applications with sampling rates below 5Msps (million samples per second). The resolution of the SAR ADC is generally 8 to 16 bits, and it has the characteristics of low power consumption and small size. These characteristics make this type of ADC have a wide range of applications. An important part related to accuracy in SAR ADC - DAC has a variety of structures, and the common ones are pure resistance type, resistance-capacitor hybrid type, and pure capacitance (charge redistribution) type. Among them, the pure capacitive DAC is widely used because of its low noise and high manufacturing precision. [0003] Purely capacitive DACs generally use metal-insu...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): H03M1/38
Inventor 陈云龑
Owner 上海菱沃铂智能技术有限公司