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Shortcut Keys for protel99 and power PCB (pads layout)Shortcut for protel99 I. Principle Image Library P/P: Draw component pins P/A: draw an arc P/L: draw a straight line P/A: Draw a rectangle T/C: Create a new component T/R: Delete the component T/E: Rename the component t/W: Create a new child for the component T/T: delete a child of the component Ii. Schematic diagram CTRL + backspace: Repeat the previous operation Ctrl + backspace: cancel the pre

Note: belong to reprint Many people for the PCB traces of the reference plane is confused, often asked: for the inner layer traces, if the line side is VCC, the other side is GND, then which is the reference plane? To figure this out, you have to understand the concept of transmission lines. We know that the transmission line must be used to analyze the signal transmission on the PCB in order to explain th

transistors and variable resistors, their packaging is the most headache, the same packaging, its pin is not necessarily the same. For example, for packaging such as to-92b, usually 1 feet is e (emitter), and 2 feet may be B-pole (base), or C (collector), the same, 3 feet may be C, also may be B, specifically that, only to get the components can be determined. Therefore, the circuit software is not hard to define the name of the pad (pin name), the same, FET, MOS tube can also be used in the sa

A process is a dynamic description of a program, which is the smallest unit of the operating system's resource allocation (the thread is the smallest unit of the operating system execution entity). for a multi-channel program system, there may be many processes in memory, in order to facilitate the management of these processes, the operating system kernel for each created process to establish a structure to save its related information. This structure is the

, when the clock frequency exceeds 100 MHz or the rising edge is less than 1 ns, the signal integrity effect becomes important. In PCB, the signal line is the main carrier for signal transmission. The cabling of the signal line directly determines the superior signal transmission, thus directly affecting the performance of the entire embedded system. Unreasonable wiring will seriously lead to various signal integrity problems, and generate timing, noi

--------------------------------------------------------------------------------------------------------------- ---------------------Sheet TechnologyThe following parameters or tables represent only part of the plate process and simulation selection parameters, the actual production will have a certain difference (but not a small deviation!). ）The simulation software uses Polar's "Si9000".1oz=28.35g,1oz copper thickness refers to 1 square feet of area on average copper foil weight equa

1-2 is omited, for more detail please referWww.usb.org. ....... 3 layout guidelines 3.1 General Routing and placementUse the following general routing and placement guidelines when laying out a new design. TheseGuidelines will help to minimize signal quality and EMI problems. The high speed USB validation effortsFocused on a four-layer motherboard where the first layer is a signal layer, the second layer is power,Third layer is ground and the fourth is a signal layer. This results in placing mos

During circuit design, there are more and more power supplies and multiple locations on a PCB, such as 48 V, 12 V-Common types of power supplies such as 12 V, 5 V,-5 V, 3.3 V, 2.5 V, 1.8v1.v, agnd (analog location) dgnd (Digital location), pgnd (Protected Area) the ground plane required for different functions, some IC clearly requires the single point grounding, and the required power supply, ground plane hollowing. In order to ensure high reliabilit

When drawing a PCB, you often need to check the corresponding components on the schematic. If the number of components is small, you can find them. Also, alicloud designer provides a good cross-search function. Here I suggest using two monitors, one with a schematic diagram and the other with a PCB, which makes it easier to find out. 1 use the shortcut key T + c This shortcut key is used in both the schem

High Frequency Circuit Wiring techniques in PCB Layout 1. Multi-board wiring High-frequency circuits often have a high degree of integration and a high wiring density. Using a multi-layer board is not only required for wiring, but also an effective means to reduce interference. In the PCB Layout stage, a proper selection of printing board sizes of a certain number of layers can make full use of the middle

Because COB does not have IC sealed Leadframe (Guide frame), but uses the PCB to replace, so the PCB welding mattress design Handy is very important, and fihish can only use electricity plated gold or enig (isotopes leaching gold), whether the Gold line or aluminum line, Even the latest brass lines have problems that can't be beaten up.PCB Design requirements for COB The finished surface of PC board

Address: http://blog.csdn.net/qq736934266/article/details/3582764 1. General rules1.1 Pre-division of digital, analog, DAA signal cabling areas on the PCB.1.2 numbers, analog components and corresponding cabling should be separated and placed in their respective cabling areas as far as possible.1.3 high-speed digital signal cabling as short as possible.1.4 The sensitive analog signal must be as short as possible.1.5 reasonably allocate power supplie

Top-level wiring layer of toplayer-signal Layer Bottom underlying wiring layer-signal Layer The connections of each pad are on the signal layer, that is, the connections of each component pin on the circuit board. Mechanical Layer -- Define the appearance of the entire PCB. In fact, when we say that the mechanical layer refers to the shape structure of the entire PCB Board. Keepoutlayer disallow the wirin

dip8 is double-row, each row has four pins, the distance between the two rows is mil, the distance between the pad is 100mil. Sipxx is the encapsulation of a single row. And so on. It is worth noting that the packaging of transistors and variable resistors is the most headache. the PINs may not be the same for the same packaging. For example, for packaging such as TO-92B, usually 1 foot is E (emission pole), and 2 feet may be B (base pole), or C (collector ); similarly, the three-legged device

Use the Keepout layer to determine the size of the line:Follow the steps in the diagram:1. Select the corresponding tag of the menu bar2. Select "Place lines" and draw line options3, in the black area of the PCB project can be drawn lineNow the line you draw is in the keepout layer, the line is pink!The boundary of the line is the boundary of the board"If you draw a line that is not pink, you need to re-select the Keepout layer!" 】Make the

Which components can be made into PCB files?In PCB design, some components do not need to be made into components for the sake of speed.It is a waste of time to make components, and there is no actual component in production.As follows (continuous update ): The PCB is connected to the PCB before the manual post w

Engineers using Protel 99SE know that Protel in the PCB drawing is not support the Chinese character input, but as a factory production debugging convenience, the inevitable in the PCB to make Chinese marks, and sometimes for the purpose of explaining the Board, attention to matters such as to enter Chinese silk screen, So how do I enter Chinese when Protel does not support Chinese? This experience will be

attributee page in the component Properties dialog box.18. Can I write the sequence number of the element symbol in the Sch diagram as a subscript?A: No.19. In the schematic diagram of PROTEL 99 and the printing plate diagram, how to deal with the linkage components (such as the potentiometer with a switch and the tuning capacitor)A: Draw a dotted line using drawing tool bar Drawing tools in sch. This problem does not exist in PCB.20. Whether automat

Project Processing capacity Process details Number of layers 1~6 Layer The number of layers refers to the number of electrical layers in the PCB (the number of copper layers). At present Jia Lixin only accept 1~6 layer board. Plate type FR-4 Plate Plate type: Cardboard, half glass fiber, all glass fiber (FR-4), aluminum substrate, at present Jia Lixin only accept FR-4 plate. As show

Label: HTTP Io strong SP Div C on r ef 1 feet = 12 inch 1 inch = 1000 mill Mil 1mil = 25.4um 1mil = 1000uin (MIL ears sometimes become British) 1um = 40uin (some companies call micro-inches as microphones, but they are actually micro-inches) 1 oz = 28.35g/square foot = 35 microns H = 18 microns 4mil/4mil = 0.1mm/1mm mm linewidth 1asd = 1 AMPS/square meters = 10.76 AMPS/square feet 1 AM = 1 amps min = 60 couplet is mainly used for precious metal plating such as gold plating 1 square me