Schematic Diagram Analysis, also known as reverse engineering of PCB schematics, involves depicting the PCB schematic based on the physical PCB or PCB files to illustrate the circuit board's principles and operations. This schematic is also used to analyze the functional characteristics of the product itself. In forward design, schematic design is generally conducted in product development, and PCB design follows the schematic as the basis and foundation. The PCB schematic can serve as a basis for reverse study, analyzing circuit board schematics and product characteristics, or it can be reused for forward design, PCB design, and PCB schematics, playing a special role. So, when it comes to the process of pushing back the anti-PCB schematic based on the file map or physical PCB, what details should be paid attention to?

Rational division of functional areas

In the intact PCB circuit board schematic diagram of reverse design, a reasonable division of functional areas helps engineers reduce unnecessary complications and improves drawing efficiency. Typically, functional components with the same function on the PCB will be focused on layout, providing a convenient and accurate basis for functional zoning in the reverse schematic.

However, the division of functional areas is not random and requires engineers to have knowledge of electronic circuits. First, identify the core component of a functional unit, and based on the connection alignment, immediately identify other components of the same functional unit to form functional partitions. The formation of functional partitions is the basis of schematic drawing. Additionally, in the process, make clever use of the serial numbers of the circuit board components, as they can aid in faster functional partitioning.

Find the base pieces

These benchmark pieces can be identified at the beginning of schematic drawing by focusing on the main components. According to these benchmark pins, ensure the accuracy of the schematic drawing to a greater extent. Finding base parts is not a complicated task for engineers. Under normal circumstances, major circuit components can be selected as benchmark parts. They are generally larger and have more conveniently drawable pins, such as integrated circuits, transformers, transistors, etc., making them suitable benchmark choices.

Correctly distinguish between lines and draw the wiring reasonably

Distinguishing between ground lines, power lines, and signal lines requires knowledge of power-related aspects, electrical connections, and PCB routing. This distinction is based on the components' connections, line copper foil width, and electronics characteristics. When drawing the wiring, extensive use of ground symbols for grounding can help avoid line crossings and interspersions. Different colors can be used for different types of lines to ensure clarity and legibility on all components. Special symbols can also be used, and even cell circuits can be separately drawn and then combined in the final schematic.

Master the basic framework and refer to similar schematics

Engineers need to not only master the composition of simple and classic unit circuits to directly draw them but also understand how to form the overall framework of an electronic circuit. It is important not to neglect the fact that similar types of electronic products often share similarities in their schematics. Engineers can leverage their accumulated experience and fully learn from similar schematics when working on new schematic designs.

Check and optimize

Once the principle figure drawing is complete, it is crucial to test, check, and optimize the links in the reverse design of the PCB schematic. This involves checking the optimization of PCB distribution parameters, sensitive component nominal values, PCB files, map-schematic comparison analysis, and reconciliation to ensure that the schematic and the file map are exactly the same. If any inconsistencies with the schematic layout are found during the checking process, schematic adjustments should be made until it reaches a completely reasonable, standardized, accurate, and clear state.