Power Calculation from Current and Resistance

Power Equation for Current and Resistance

P = I² R

Current (I) in Amps Resistance (R) in Ohms

Resulting Power

0.00 W

Power Calculation from Voltage and Resistance

Power equation for voltage and resistance

P = V² / R

Voltage (V) Resistance (Ω)

Resulting Power

0.00 W

Power Calculation from Voltage and Current

Power Equation for Voltage and Current

P = V x I

Voltage (V): Current (A):

Result: -- W

Voltage Divider Calculator

Voltage Divider Calculator

Input Voltage (Vin)

Resistor R1 (Ω)

Resistor R2 (Ω)

Calculated Output

8.00 V

Equation: Vin × (R2 / (R1 + R2))

Parallel Resistance Calculator

Parallel Resistance Calculator

R1

R2

Total Equivalent Resistance

0.00 Ω

SMD Pad Size Calculator for PCB Design

SMD components require precisely sized soldering pads during assembly. Many of the footprints created by PCB designers are still based on data sheets and IPC-7351's standard pad and land size calculations as below.

Enter A,B and C Values in mm: PAD SIZE (X/Y)

X: 0

Y: 0

PAD LOCATION (X/Y)

X: 0

Y: 0

PTH Hole and PAD Size Calculator

PTH Hole and PAD Size Calculator Refers to IPC-2222

According to IPC-2222 standard, there are three design producibility levels of features, tolerances, measurements, assembly, testing of completion or verification of the manufacturing process that reflect progressive increases in sophisticaltion of tooling, materials or processing and, therefore progressive increases in fabrication cost. These levels are:

Level A : General Design Producibility - Preferred

Level B : Moderate design Producibility - Standard

Level C : High Design Producibility - Reduced.

Below is the calculator for the PTH hole and PAD design.

Enter maximum Component Lead diameter in mm:

Level A of IPC - 2222

Hole Diameter in mm       : 0

Pad Diameter in mm       : 0

Level B of IPC - 2222

Hole Diameter in mm       : 0

Pad Diameter in mm       : 0

Level C of IPC - 2222

Hole Diameter in mm       : 0

Pad Diameter in mm       : 0

General PCB Routing Techniques

For traces that don't need specific impedance or high current, a 10 mil trace width is fine for the vast majority of low-current analog and digital signals. Printed circuit board traces that carry more than 0.3 A may need to be wider.

 Route the signal in a daisy chain.

Do not route the signal over split planes

Avoid plane obstruction (slot) whenever possible. If routing over them is unavoidable, use stitching capacitors.

Add dedicated ground vias close to the source and sink of the signal.

Do not use right-angle traces.

Transition vias to pads, notably between thin and thick traces on the output pins. The teardrop approach reduces thermal stress during the signal transition. This procedure prevents traces from cracking and increases their mechanical strength.

Route traces in parallel pairs when routing around an object to avoid differential impedance and discontinuities caused by split traces

Place passive components within the signal path, such as source-matching resistors or ac-coupling  capacitors, and next to each other. Placing components in parallel creates wider traces spacing. Staggering components is not recommended as it creates narrow areas.

Avoid the route entry to pad which could cause component shiftting during reflow due to solder pull.

Avoid introducing bends into high-speed differential signals. Maintain a bend angle of more than 135° to achieve the loosest bend feasible. Consider the high-speed signal bending rule as shown below.

Try to increase the spacing between traces whenever possible

Vias cause a significant discontinuity in impedance. Try to keep the number of placed vias to a minimum and put them symmetrically.

It is preferred to route all of the data and clock signals on the same layer.

Voids in reference planes can occur when vias are placed close to together. Be aware of such voids when routing high-speed signals. To avoid large void areas, ensure appropriate space between vias. Sometimes it is preferable to place fewer ground and power vias in order to eliminate via voids.

The return path must be considered at both the signal's source and sink. The left figure below depicts a poor example. Because there is only one ground route on the source side, the return current cannot go back over the reference ground plane as intended. The top layer's ground connection serves as the current's return channel. The difficulty is that the signal trace's impedance is calculated with reference to the ground plane rather than the ground trace on the top layer. As a result, ground vias must be placed on both the source and sink sides of the signal. This allows the return current to travel back along the ground plane.

EMC by Design - Systematic Approach (Emission Control - Components & Circuits)

 

EMC by Design - Systematic Approach (PCB Layer Stack up)

 

EMC by Design - Systematic Approach (Grounding - Signal Reference Ground, 0V)