kicad pcb

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

Address: http://pda.c114.net/164/a565914.html Introduction Signal integrity refers to the signal quality in the circuit system. If the signal can be sent from the source end to the receiving end without losing sight within the required time, it is called that the signal is complete. With the rapid development of semiconductor technology, the output speed of IC switches is improved, and the signal integrity problems (including signal overshoot and underloading, ringing, reflection, crosstalk, an

Before the introduction of the PCB (Process Control block), the first implementation of a ' progress bar ', and then according to the program written to analyze the specific PCB implementation principles. The ' progress bar ' function is able to be displayed in a single line, while the progress bar has a dynamic growth change, to know the ratio in the progress bar, but also need to be able toShows you know

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

PCB packaging is mainly divided into SMD and plug-in type1) SMD Component Package DescriptionLED: color has red, yellow, green, blue points, brightness divided Puliang, highlighting, super bright three and so onClass, the commonly used package form has three types: 0805, 1206, 121 (commonly used package is rb.1/.2)the extension is: 0805C, 0805D, 0805L, etc. Diode: According to the limit of the current withstand, the package form is broadly divide

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

Formula for propagation delay of cabling in PCB The first half is information from altera. The propagation latency (tPD) is the time required to transmit a signal from one point to another. Transmission Line propagation delay is a function of the relative dielectric constant of materials. Propagation delay of micro-Strip Layout You can use formula 5 to calculate the propagation delay of the strip layout. Formula 5: Delayed propagation in the line

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

First, preface:The so-called interaction is such, in the schematic click on a component, in the PCB diagram is selected, so that the component just lead into the PCB layout of the components can provide us with great convenience.Second, the premise:Importing components in the PCB is this way: Where the path is the path where the schematic is located.

Transferred from Zhang Fei actual combat electronic public numberGeneral principles of PCB cablingShortest path and reduced interferenceThe overall process of PCB cabling is as follows:1 understand the manufacturing specifications of manufacturers-line width, line spacing, over-hole requirements and layer requirements;2 Determine the number of layers and define the functions of each layer;3 Design Cabling r