How to Judge the Acceptance of PCB Quality
Which Color Circuit Board Sells the Most Expensive
Method to Solve the Noise Interference of Power Supply on High-frequency PCB Board
Disassembly Skills of Chip Components on PCB
What Factors Should Be Considered in the Selection of High-frequency PCB CCL
How to Place Special Components during PCB Layout
What Are the Functions of Capacitors in Circuits?
Testing Techniques for Common Electronics Components
What to do if There is a Short Circuit on the PCB
Desoldering Principles and knowhow during PCBA Processing
Black Oxidation of the Inner Layer of the Multilayer PCB
How to Ensure the High-performance Design of PCB
What Is the Printing Process of SMT Solder Paste?
PCB without fiducial mark, Is There Any Way to do SMT for It
What Are the Benefits of Reserving Break-up Tab for PCB Production
How Does SMT Affect PCB Production Time and Speed It Up
Classification of PCBs from three aspects
Common Problems and Solutions for Dry Film pasting during PCB Manufacturing process
Several Elements to Inspect after PCB Design
What is a halogen-free circuit board?
What Do Capacitive Coupling and Decoupling Mean?
What Are the Differences Between PCB Paste Mask and Solder Mask?
How PCBA Is Packaged and Shipped
How long can PCBA finished products be stored?
What Are the Differences and Relations Between PCB, PCBA, and SMT?
PCB Baking Specifications
PCB "Solder Mask Tenting" and "Solder Mask Opening"
Five reasons for PCB deformation and six solutions
Importance of first article inspection of PCBA board
Temperature zone standard for SMT reflow soldering
Small and medium volume PCB manufacturers in China
The main reason for PCBA cleaning
For power filter, the more capacitors, the better?
What does PCBA programming mean?
Content of PCB incoming testing
What conditions must be met for PCB circuit board soldering?
What is Blind via and Buried via
PCBA Manufacturers Temperature and Humidity Sensitive Components Management
Why choose Shenzhen SMT processing factory?
How long does it take to calculate the quotation for PCBA manufacturing?
Introduction of PCB design clearance requirements
Explanation of BOM, DIP, SMT, SMD
Introduction of the process of PCBA prototype
How to prevent pseudo soldering or cold soldering defects in PCBA manufacturing?
Factors that affect the Price of FPCB
What information is required for SMT processing at PCBA factory?
Skills of using 0ohm resistor in PCB design
How to select a PCBA manufacturer
SMT processing solder joint quality inspection
Characteristics difference between immersion gold PCB and gold plating PCB
Common malfunctions of Circuit Board Caused by Moisture
A Few Rules about PCB Panelization
Compare of multi-layer PCB with single/double layer PCB
Why do we need to introduce so many subdivided GND
Difference between immersion gold boards and gold plating boards
Aluminum PCB structure
Classification of different GND in circuit
Why PCB baking is necessary during manufacturing process
The handle and precautions of OSP board in SMT process
How to choose capacitors for filter decoupling
How to choose filter capacitor for switching power supply
5 database need for SMT process
Function of three-terminal capacitor
Introduction of PCB OSP surface treatment
Method of inspecting the quality of SMT by step
How to find the short point between VCC and GND
Difference between 850nm and 940nm infrared LED
Component layout of PCB SMT DFM
Pad shape influence on the strength and reliability of the soldering joints
The difference between high temperature solder paste and low temperature solder paste
Introduction to manual welding processing
Manual visual inspection in PCBA processing
Characteristics of the conformal coating process
Difference between hardware engineers and software engineers
PCBA processing operation rules
China PCB upstream materials has continued to soar
Difference between serial buses and parallel buses
The key points of quality control in PCBA processing
Common causes of solder beading during SMT process
Analysis of the advantages and disadvantages of HASL PCB surface
Requirements for layout of components during SMT assembly
Selection of electronic components and CCL for PCBA
Performance and appearance quality inspection of components.
Quality and Reliability of SMT Chip Processing and Production
Coupling and decoupling function of capacitor
Two methods to connect digital ground and analog ground
Common sense in SMT process

Two methods to connect digital ground and analog ground

1. Understanding of digital ground and analog ground

Digital ground:
The digital signal only has 0 and 1, so the digital ground is the 0 signal, but this signal is usually not 0, and will be somewhat higher than 0. But if it does not reach 1, it is still 0. That is to say, its high and low levels are all within a range. Because of this, the digital signal has strong anti-interference ability.

As we all know, the rising edge of the digital signal is relatively steep and contains rich high harmonics. These high harmonics may not have much influence in the digital circuit, because usually the high frequency interference voltage is very low, and the anti-interference ability of the digital signal is strong.

Analog ground:
The analog ground is a real zero potential. The problem lies here. If the two grounds are directly connected together, the digital ground will pull up the analog ground and pass the high harmonics in the digital circuit to the analog circuit through the analog ground. It will really affect your analog measurement.

The fundamental reason for the interference is that the resistance of the copper foil on the circuit board is not 0. Only by separating the analog ground from the digital ground and minimizing the common ground resistance between the two grounds can the degree of interference of the analog ground be minimized. .

2. Processing method between digital ground and analog ground

Usually there are two processing methods between digital ground and analog ground:

1. Connect with magnetic beads

① Magnetic beads are ferrite materials with good impedance characteristics in high frequency bands. They are specially used to suppress high frequency noise and spike interference on signal lines and power lines, and they also have the ability to absorb electrostatic pulses.

② Magnetic beads have high resistivity and permeability, which is equivalent to a series connection of resistance and inductance, but the resistance value and inductance value change with frequency.

③It has better high-frequency filtering characteristics than ordinary inductors, and exhibits resistance at high frequencies, so it can maintain a higher impedance in a relatively wide frequency range, thereby improving the frequency modulation filtering effect.

2. Connect with 0 ohm resistor

①The DC potential can be ensured to be equal.

②Single point grounding to limit noise.

③It has an attenuation effect on noise of all frequencies (0 ohms also have impedance, and the current path is narrow, which can limit the passage of noise current).