The clever use of 0 ohm resistors in circuit design

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Zero ohm resistors are also called jumper resistors. They are special-purpose resistors. The resistance of a 0 ohm resistor is not really zero. An ohm resistor is actually a resistor with a very small resistance value.

This article analyzes the clever uses of 0 ohm resistors in circuit design.

Convenient compatibility, debugging, and testing

Compatibility

If compatibility issues are not considered when designing PCB boards, there may be considerable trouble during the debugging stage.

For example, a certain pin of a chip can drive both a buzzer and an LED.

At this time, you can decide whether to drive a buzzer or an LED by soldering a zero-ohm resistor.

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When the matching circuit parameters are uncertain, replace them with 0 ohms. During actual debugging, determine the parameters and then replace them with components with specific values. Measuring

current

The conventional method for testing the power consumption of a circuit during operation is to test the current and calculate the power consumption, and testing the current usually requires the ammeter to be connected in series to the circuit for measurement.

During the circuit design stage, place a zero-ohm resistor in advance where the current needs to be measured.

When the current needs to be measured, this zero-ohm resistor can be removed first to facilitate the connection of the ammeter. After the measurement, the zero-ohm resistor can be soldered on. Convenient

wiring

During the PCB layout and wiring stage, especially when the circuit board area is small, the connection lines are many, and the number of layers is small. Sometimes a certain connection line needs to be wound around a large circle before it can be connected. At this time, you can consider a zero-ohm resistor.

The above picture shows a 0 ohm resistor used as a crossover on a single-sided PCB.
Suppressing circuit noise

Zero ohm resistors can suppress loop currents and thus suppress noise. Zero ohm resistors actually play a role in attenuating noise in all frequency bands.

Improving reliability and safety

Zero ohm resistors can replace pins and dip switches.

In high-speed circuits, vacant pins are equivalent to antennas, which can easily interfere with signals.

Dip switches have the risk of being messed up, causing circuit errors.

Therefore, in order to improve reliability and safety, zero ohm resistors can be used instead.

Acting as a capacitor or inductor

Acting as an inductor or capacitor under high-frequency signals.

In high-frequency circuit systems, zero ohm resistors can act as a small capacitor or inductor when matching the characteristics of external circuits. For example, adding a zero ohm resistor between ground and ground, or between the power supply and the chip pin can solve EMC problems.

Isolating digital ground from analog ground

In mixed circuits such as digital and analog, it is often required that the two grounds be separated and connected at a single point to avoid mutual interference between current signals of analog and digital circuits when they are working. However, at the board level, the ground wires are usually connected together at the end. At this time, letting the analog ground and digital ground pass through a zero-ohm resistor before connecting them together can play a certain isolation role.

In addition, another advantage of doing this is that the ground wire is divided into two networks, which will be much more convenient when processing large areas of copper. As a side note, in such occasions, inductors or magnetic beads are sometimes used for connection. (Transferred)

UUC

Thanks for sharing. The explanation is very systematic. I learned a lot.

极限零

It does have many functions, but I only have one function, which is used for crossing lines when wiring. . .

nian1206

Mark it, I will use it later. Thank you very much for sharing. Good people will have a peaceful life.

nian1206

Mark it, I will use it later. Thank you very much for sharing. Good people will have a peaceful life.

beyond_笑谈

In order to save costs, the TV power supply uses CAM-1 board, single-sided board, and uses a lot of O ohm resistors or jumpers, mainly for easy wiring.