Zero ohm resistor on circuit board

Compared with some people who have heard of zero ohm resistor, what is its role? In the work of electronic engineers. Circuit design is a common contact. Resistors are one of the most familiar components in circuit design, and they play the role of voltage dividing and current limiting in the circuit. So I have a question for you: the zero-ohm resistor of electronic components. Do you know what role this device can play in a circuit? If you don’t know, hurry up and learn with me!

In fact, there is a difference between zero-ohm resistance and direct wire connection, and zero-ohm resistance has many ingenious uses in circuit design.

1. Debugging and compatibility

We need to consider compatibility issues as much as possible when designing PCB boards, because after a circuit board is made and physically printed and coated with copper, it is physically fixed. If compatibility issues are not fully considered during design, it will bring a lot of inconvenience to engineers during the circuit board debugging stage.

For example: a certain pin of the chip has two functions, such as driving a buzzer and driving an LED light. However, these two functions cannot work at the same time. In order to implement it on the same circuit board, you can choose which period to drive. At this time, you can add a zero-ohm resistor to the line connecting the buzzer and LED, and solder the zero-ohm resistor on which path. The European circuit decides whether to drive the buzzer or the LED light.

2. Convenient wiring

During the PCB layout and wiring stage, sometimes the wiring always fails, especially when the circuit board area is small, there are many connections, and there are few layers. If you encounter a connection that requires a large circle to connect, you can consider whether you can easily skip the wire in front of you by connecting a zero-ohm resistor instead of making a large circle.

3. Reserve the resistor position

If in the circuit design stage, it is not sure what value of resistor needs to be connected to a certain position, then you can leave a soldering position for the resistor at that position and solder a zero-ohm resistor. During actual circuit debugging, resistors with different resistance values ​​can be easily changed. After debugging, the resistance parameters are determined and then a suitable resistor is connected.

4. Convenient for testing current

After designing a circuit system, it is usually necessary to test the power consumption of the entire circuit when it is running. The conventional method is to measure the current and then use the current to calculate the power consumption. The method of testing the current is usually to insert an ammeter into the circuit and measure it. At this time, if you place a zero-ohm resistor where the current needs to be measured, remove the resistor and connect the ammeter when measurement is needed. During normal operation, just solder the zero-ohm resistor directly.

5. Noise suppression

Due to the characteristics of the zero-ohm resistor itself, the loop current can be effectively suppressed, thereby suppressing the noise. In fact, zero ohm resistance does not really mean no impedance. Only superconductors can truly achieve zero impedance. Therefore, the zero-ohm resistor actually plays an attenuating role in all frequency bands.

6. Security protection

It is often seen on many circuit boards that there are many pins that need to be terminated with jumper caps. Or use a dip switch to control whether the circuit is closed. Although these two methods are more convenient during the debugging stage, it is best to use them as little as possible when making products. Since in high-frequency circuits, empty pins act as antennas, it is easy for signals to be interfered with. In addition, the DIP switches can easily be messed up by unsuspecting people, causing errors in the circuit system. Therefore, for safety reasons, it is best to use zero-ohm resistors instead of pins and DIP switches. It can avoid misoperation and reduce maintenance costs.

7. Act as a capacitor and inductor

In high-frequency circuit systems, zero-ohm resistors can act as a small capacitor or inductor if they match the external circuit characteristics, which can effectively solve EMC problems. For example, between ground and ground, or between power supply and chip pins.

8. Ground isolation

In chip design, the ground of analog circuits is called AVSS, and the ground of digital circuits is called VSS. AVSS and VSS are usually separated inside the chip because separating the bottom lines can prevent the current signals from interfering with each other when analog circuits and digital circuits are working. However, at the board level the grounds are usually connected together in the end. At this time, letting the chips AVSS and VSSPIN pass through a zero-ohm resistor before connecting them together can provide a certain isolation effect.

The above are some of the wonderful uses of zero-ohm resistors introduced this time. As a hardware electronics engineer, knowing more about some design skills will help you solve problems conveniently and quickly at work. In addition to the use of zero-ohm resistors introduced this time, there are also the use of transistors, the wonderful uses of capacitors, the use of inductors, and various design software and simulation software used in circuit design, which can improve work efficiency. The above is the function of zero ohm resistor. I hope it will be enlightening after reading the fight.