PCB Design: 24 tips for Reducing noise and electromagnetic interference.

With the continuous improvement of the sensitivity of electronic components, the requirements for the anti-interference ability of instruments are becoming higher and higher, and the design of PCB is becoming more and more difficult, how to improve the anti-interference ability of PCB has become the focus of attention of many engineers and technicians. 1oz vs 2oz This article introduces some techniques for reducing noise and electromagnetic interference in printed circuit board design.

The following are 24 tips for reducing noise and electromagnetic interference in PCB design, which are summarized through years of design:

It is possible to use low-speed chips instead of information high-speed development chips, how to test a circuit board with a multimeter and high-speed chips are used in critical areas.

The series resistance method can reduce the jump rate of the upper and lower edges of the control circuit.

Apply some form of vibration damping to the relay whenever possible.

Use the minimum frequency clock that meets system requirements.

The clock generator is as close as possible to the device that uses the clock. The quartz crystal oscillator housing must be grounded.

Circumvent a clock work area with a ground wire to keep the clock line as short as possible.

I/O drives the circuit as close to the edge of the board as possible to get it off the board as quickly as possible. The signal entering the printed circuit board should be filtered, the signal from the high noise area should also be filtered, and the method of series resistance should be used to reduce the signal reflection.

MCD terminals should be connected, grounded, or defined as output terminals. The terminal should be powered on and not suspended in the air.

The idle idle gate input is not suspended, the idle idle operational amplifier is grounded, and the negative input is connected to the output.

Printed boards try to use 45° polyline instead of 90° polyline to reduce the emission and coupling of external high-frequency signals.

The printing plate can be reasonably divided according to the frequency and current through the switching characteristics, and the noise component and the noiseless component should maintain a certain distance from the enterprise.

Single panel and dual panel power supplies use a single point connection, ground with a single point, as thick and affordable as possible, and multi-layer board power supplies reduce ground capacitance and inductance.

Clock, bus, and segment signals should be kept away from Iu002Fo wires and plugs.

Analog voltage input lines, as far as possible away from digital circuit signal lines, especially clocks.

In A Class A device, the digital and analog parts are preferably unified or uncrossed.

The clock line has less interference with parallel I/O lines than the I/O line, and the clock data pin has a distance from the I/O cable.

Component pin as short as possible, decoupling capacitor pin as short as possible.

The boundary should be as thick as possible, with protection on both sides. The express line should be straight.

Noise sensitive lines shall not be parallel to high current, high speed switching lines.

Wiring under noise-sensitive instruments is not allowed under time-sensitive crystals.

The weak signal control circuit cannot form a working current loop around the low-frequency circuit.

The signal cannot form a loop, if inevitably, so that the loop area is as small as possible.

Each integrated circuit has a decoupling capacitor. Add a small bypass capacitor on each side of the capacitor.

Large capacity tantalum capacitors or tantalum capacitors can be charged and discharged without electrolytic capacitors. When tubular capacitors are used, the housing should be grounded.