Archive for the ‘PCB Design’ Category

PostHeaderIcon Identify the circuit board track layout

Identify the circuit board track pattern dissipation and layout circuit board track pattern logically:

For distinguish of ground plane, power supply circuit and signal circuit, also require engineer to have related power supply, circuit connection, circuit board layout and PCB Reverse Engineering knowledge. How to distinguish these different kinds of circuit can rely on component connection situation, copper thickness and feature of electronic product.

During the process of PCB layout & PCB Clone, in order to avoid the cross line, large bulks of ground signal can be applied on the ground plane, different circuit can use different colors to help distinguish one another, also specified symbol can use on specified components, can even separate unit circuit and draw them. And finally can integrate them together.

PostHeaderIcon Crack IC PIC16C56A Heximal file

We can Crack IC PIC16C56A Heximal file, please view the IC PIC16C56A features for your reference:

Data memory is composed of registers, or bytes of RAM. Therefore, data memory for a device is specified by its register file. The register file is divided into two functional groups: special function registers and general purpose registers if Crack IC Heximal file.

The special function registers include the TMR0 register, the Program Counter (PC), the Status Register, the I/O registers (ports), and the File Select Register (FSR) when Crack IC Heximal file.

In addition, special purpose registers are used to control the I/O port configuration and prescaler options. The general purpose registers are used for data and control information under command of the instructions before Crack IC Heximal file.

For the PIC16C56A, the register file is composed of 7 special function registers and 25 general purpose registers after Crack IC Heximal file.

The Special Function Registers (SFRs) are registers used by the CPU and peripheral functions to control the operation of the device The special registers can be classified into two sets when Crack IC Heximal file.

The special function registers associated with the “core” functions are described in this section. Those related to the operation of the peripheral features are described in the section for each peripheral feature after Crack IC Heximal file.

This register contains the arithmetic status of the ALU, the RESET status, and the page preselect bit for program memories larger than 512 words. The OPTION register is a 8-bit wide, write-only register which contains various control bits to configure the Timer0/WDT prescaler and Timer0 if Crack IC Heximal file.

By executing the OPTION instruction, the contents of the W register will be transferred to the OPTION register. A RESET sets the OPTION<7:0> bits when Crack IC Heximal file.

PostHeaderIcon 2 Different Amplifier

2 Different Amplifier

Different amplifier can only magnify the D-VALUE of 2 signals, but won’t magnify general voltage signal. If design job of different amplifier and Printed Circuit Board aren’t reasonable, when signal level in the low status, general voltage will generate a small differential interference signal. Due to the high input impedance of different amplifier, any parameter imbalance on input point will bring much great interference to circuit. Therefore, during the printed circuit board design process, it has to ensure physical structure of amplifier complete symmetry.

There is a leakage resistance exist in the input point of different amplifier, it can take an effect of imbalance voltage deviation. Designer can solve this problem through add protective device on the input circuit, protective device can circle the signal wire, if it can keep the same voltage with 2 input signal low level, as a result of that, positive resistance value will increase. This device can ensure signal source terminal and protector keep the same voltage with low level of signal source.

PostHeaderIcon 1 High gain DC amplifier

High gain DC amplifier generally being used to amplify small signal. When crystal transistor or DC amplifier being soldered on PCB Board, thermocouple will be formed between copper layer and component lead, therefore will occur different AC voltage, it will has interference signal against amplifier. In order to keep the minimum temperature fluctuation rate around DC amplifier INPUT point, and remain the balance, we suggest to separate INPUT point with part to avoid the influence caused by air flow.

PostHeaderIcon Reasonable Analog Signal Circuit Layout in the PCB Board

In the analog circuit PCB Board, signal circuit can fulfill a variety of functions, such as signal input, feedback, output and provide standard signal. Therefore, refers to different applications, signal circuit must be optimized through different ways. However, there is an commonly known principle that in all the analog circuit PCB Board, signal circuit should be as short as possible, that is because the longer signal circuit, the more chances it can involve inductance and capacitor, that is the last thing PCB design engineer want to see. But the fact is impossible to make all the signal circuit to its shortest level. Therefore we have to take the most readily having interference signal circuit layout into account.

 

Below signal circuit layout need particular attention during PCB layout:

1> High frequency oscillator / amplifier;

2> Multi-level amplifier, especially with high output power;

3> High gain DC amplifier;

4> Minor signal amplifier;

5> Differential amplifier;

PostHeaderIcon Which method is better for PCB Layout, manually or automatically?

If we choose to use auto layout, till which level it can support? Such as how many layer it can be? What frequency it can achieve?

All the PCB designers I have ever encountered prefer to choose layout PCB manually, because they say the auto-layout don’t have good result compare with layout manually. From my point of view, IC layout is more difficult and complicate than PCB layout, but why IC layout can use auto-layout nor PCB?

Precisely speaking, no matter auto-layout or manual-layout, there should be a principle ahead, that is: rule driven. Those designers who claim that auto-layout is not good because most of the rules are still embedded in their mind, and haven’t yet integrate into the design, so the auto-layout won’t achieve their requirement.

Frankly speaking, the rule set up for auto-layout can’t be achieve 100%, so after PCB Layout finish, we still need to modify it manually.

So there is a balance among here, if the time you spend on integrate the rule into software has already longer than the time have been taken for PCB layout manually, it is not necessary to make auto-layout.

So few designers auto-layout high frequency, because almost every line of high frequency PCB has restriction, so if we need to add rule to each network, there surely more time we need to spend than manually layout.

PostHeaderIcon Common component PROTEL package list 2

Most commonly Resistor package datasheet of PROTEL SE

Resistor: AXIAL0.3-AXIAL0.7, 0.4-0.7 stands for resistor length, normal version is AXIAL0.4.

PROTEL SE DIODE package datasheet

Ceramic capacitor: RAD0.1-RAD0.3, 0.1-0.3 stands for size of capacitor, normal version is RAD0.1;

Electro: RB.1/.2-RB.4/.8, .1/.2-.4/.8 means the value of capacitor. Normal if below 100uF will use B.1/.2,100uF-470uF choose RB.2/.4, larger than 470uF use RB.3/.6.

Diode: Diode 0.4-Diode 0.7, and 0.4-0.7 means the length of diode, normally use Diode 0.4: RB .1/.2.

Integrated Circuit: DIP8-DIP40, 8-40 means the quantity of pins, 8 pins stand for DIP8.

PROTEL SE SMD resistor

0603 stands for the package size, no relations with concrete value;

But the package size and power do have some relationship as below:

0201 1/20W
0402 1/16W
0603 1/10W
0805 1/8W
1206 1/4W

The relations among capacitor size and package see as below:
0402=1.0×0.5
0603=1.6×0.8
0805=2.0×1.2
1206=3.2×1.6
1210=3.2×2.5
1812=4.5×3.2
2225=5.6×6.5

Refers to the component package we have mentioned before, except those components inside the DEVICE.lib database, components in other databases are all have fixed package format, that is because components in the library has different kinds of format: take the transistor as reference, it is one of the most commonly used components, in the DEVICE.lib database there is only simple difference between NPN and PNP. Actually, if it is 2N3055 of NPN, then it probably TO-3, if it belongs to 2N3054 of NPN, then it probably TO-66 or TO-5, also for CS9013 we have TO-92A, TO-92B, TO-5, TO-46, TO-52.

Another one is capacitor, in the database of DEVICE, it can be simply called as RES1 & RES2, no matter is could be 100Ω or 470KΩ, they could be the same. As for circuit board, it can use has no relation with OHM value, just depends on power value of the resistor to decide if we choose 1/4W or 1/2W, and all of them can use AXIAL0.3 component package. If the power value larger than normal we can choose AXIAL0.4, AXIAL0.5 etc. now we list most commonly used component package as below for your reference:

Resistor and non-polarity double end component: AXIAL0.3-AXIAL1.0

Non-polarity capacitor: RAD0.1-RAD0.4

Polarity capacitor: RB.2/.4-RB.5/1.0

Diode: DIODE0.4 and DIODE0.7

PostHeaderIcon Common component PROTEL package list 1

Component package means the cosmetic performance and soldering point location on the circuit board when it is being assembled, it is definitely space concept. So different components can use same package, same components do have possibility to apply different package. Like Resistor, has traditional DIP package, these kinds of components usually have large size, circuit board must be drilled before assemble, after drilling and insert the components, pass through solder tin oven or manual soldering, the cost could be high, updated designs are all applied small size SMD component, this type of package don’t need drill hole, use stainless stencil as silkscreen to pour solder tin onto surface of circuit board and then place SMD component on it for assembly.

Most common component package datasheet:

RES1,RES2,RES3,RES4;feature is axial series;
RAD:cap; feature is RAD-0.1 to RAD-0.4

Electro; feature is RB.2/.4 to RB.5/1.0
Potentiometer:pot1,pot2;feature is VR-1 to VR-5
Diode:feature is diode-0.4 (low power)diode-0.7 (high power)
Triode:common feature is to-18, to-22(high power triode)to-3(high power NPN)
Regulated power supply has 78 and 79 series;78 series include 7805,7812,7820, etc.
79 series has 7905,7912,7920 etc.
Most common package include TO-126h and TO-126v
Rectifier bridge:BRIDGE1,BRIDGE2: package feature D series(D-44,D-37,D-46)

PostHeaderIcon PCB Schematic Diagram Design proces

The design of schematic diagram should use SCHEMATIC DIAGRAM design system of PROTEL98 or PROTEL99SE to draw a schematic diagram, it is the foundation of circuit board design project. During this process, designer should take advantage of all kinds of drawing tools and edit functions provided by software, the process is see below:

1. Start-up: open up PROTEL98 schematic diagram editor:

Click “Start” bottom, and choose PROTEL98 inthe “Program”.

2. Install circuit drawing dimension and layout

User can install the dimension, orientation and grid size of drawing and title.

3. Place necessary components on the schematic diagram

User select the necessary components from database and place them onto the right place according to circuit schematic diagram requirement, as well as modification.

4. Layout the components which have been placed

Use line and signal to connect all the components on platform to constitute a complete schematic diagram

5. Modify components after PCB layout

In order to ensure the schematic diagram’s preciseness and aesthetic, components location need to be modify through delete, move and adjust drawing size, feature and orientation.

6. Save file and print output

Save schematic diagram which has been edited and print it out for file.

PostHeaderIcon In order to ensure the working temperature of components below its highest level

1>    Analyze circuit diagram and understand the greatest power consumption;

2>    Confirm the highest allowed working temperature of component surface, it depends on the component itself and isolated environment.