Camera Module Circuit Layout for Digital-Analog EMI Isolation
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Solution Overview
Problem
Conventional camera modules suffer from electromagnetic interference between digital and analog circuit units, leading to reduced signal transmission capability and increased complexity, while also being bulky due to mixed circuit layouts.
Innovation Solution
The camera module features a substrate with separate digital and analog circuit units, maintaining a safe distance between them to prevent electromagnetic interference, and incorporates a molding base to integrate and reinforce the circuit board, reducing size and enhancing stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If digital circuit unit and analog circuit unit are disposed in mixed manner on the same circuit board, then the circuit board complexity is reduced, but electromagnetic interference occurs from digital to analog circuits
Solution Approach 1:
The circuit board is divided into distinct digital circuit region and analog circuit region, with digital circuits (including digital signal processing and control) placed in one area and analog circuits (including photodetector signal amplification and conversion) placed in another area. This spatial segmentation prevents electromagnetic interference while maintaining manageable circuit board complexity.
Solution Approach 2:
The digital circuit unit is extracted and separated from the analog circuit unit, with each unit disposed in its own dedicated region on the circuit board. This extraction eliminates the harmful electromagnetic interference from digital circuits to analog circuits while allowing each unit to be optimized independently.
2Reliability
If digital circuit unit and analog circuit unit are separated to prevent electromagnetic interference, then signal transmission capability is improved, but circuit board complexity increases
Solution Approach 1:
Different regions of the circuit board are assigned different functional qualities: the digital circuit region is optimized for high-speed digital signal processing with appropriate grounding and power supply, while the analog circuit region is optimized for low-noise signal amplification with shielded pathways. This local quality differentiation improves signal transmission capability without requiring complete physical separation that would increase overall complexity.
Solution Approach 2:
A shielding structure or ground barrier is introduced as an intermediary between the digital circuit unit and analog circuit unit. This intermediary element blocks electromagnetic interference from reaching the analog circuits while maintaining a relatively simple overall circuit board layout, thus improving signal transmission without proportionally increasing complexity.
3Ease of manufacture
If mixed circuit layout is used, then manufacturing process is simplified, but electromagnetic wave interference reduces signal processing ability
Solution Approach 1:
The circuit board layout is segmented into standardized digital and analog regions with clearly defined boundaries and routing rules. This segmentation provides simple manufacturing guidelines while ensuring that electromagnetic interference does not degrade signal processing ability, as each region can be manufactured and tested independently.
4Volume of moving object
If camera module size is reduced for lightweight devices, then device portability is improved, but space for separate digital and analog circuits is limited
Solution Approach 1:
The circuit board utilizes three-dimensional space by routing signals through multiple layers and employing vertical stacking of circuit elements. This allows digital and analog circuits to be closely positioned in the planar dimension while maintaining electromagnetic isolation through layered construction, thus reducing overall camera module size without forcing complex two-dimensional layouts.
Solution Approach 2:
The circuit board employs nested positioning where the digital circuit unit and analog circuit unit are arranged in a compact nested configuration, with shielding structures and signal pathways efficiently packed within the limited space. This nesting approach minimizes the overall camera module footprint while maintaining the necessary separation for electromagnetic isolation.
Data Source
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AI summary
The present invention provides a camera module and a molding circuit board assembly, circuit board and application thereof, the circuit board comprising a digital circuit unit, an analog circuit unit and a substrate. The digital circuit nit and the analog circuit unit are respectively formed on the substrate, and the digital circuit unit and the analog circuit unit are conductively connected to each other, wherein at least one part of the analog circuit unit has a safe distance from the digital circuit unit, so as to prevent an electromagnetic wave generated by a circuit of the digital circuit unit from interfering with an electrical signal transmitted and processed by the analog circuit unit, thereby improving the stability and reliability of the transmission and the processing of the electrical signal by the circuit board.