Why Use a Passive Probe to Measure Power Ripple

In the field of electronic test and measurement, detecting ripple (Ripple) in circuits is a crucial task, especially in power supply and signal integrity analysis. Ripple usually refers to the residual AC component in the DC output of a power supply, which may have a negative impact on the performance of electronic devices. Therefore, the selection of suitable test equipment is essential for accurate measurement of ripple. Among many test equipment, passive probes have become the preferred tool for measuring power ripple due to their unique advantages.

A passive probe is the 1 measurement tool without active circuit components, and is commonly used on test equipment such as oscilloscopes. Compared with the active probe, the passive probe does not need an external power supply, which makes it possible to avoid noise interference introduced by the power supply itself during the measurement process. When measuring the power ripple, we usually focus on the high-frequency part of the signal, and the high-frequency response capability of the passive probe can meet these 1 requirements. Since there is no additional power supply, the response of the passive probe can better cover the signal of the high frequency part, so that the noise ripple of the power supply can be measured more accurately.

In addition, the passive probe does not cause additional interference to the circuit under test. Although the active probe can be externally powered, it will introduce additional interference signals, which may cause inaccurate measurement results. The passive probe avoids this problem and can more accurately measure the noise ripple of the power supply. This is especially important in applications that require high-precision measurements.

The passive probe also has a smaller size and weight, which makes it more convenient to carry and use in actual measurement scenarios. During the measurement process, we usually need to move the probe to different positions for measurement. If the probe size is too large or the weight is too heavy, it will cause inconvenience to move. Passive probes are usually lightweight and can be easily connected to different parts of the circuit, thereby improving the flexibility and efficiency of measurement.

Of course, passive probes also have some limitations in measuring power ripple. For example, the frequency response of a passive probe may not be as broad as that of a coaxial line, and some high-frequency ripple components may be missed. However, in most cases, the high-frequency response capability of the passive probe is sufficient to meet the measurement requirements. In addition, passive probes may introduce signal attenuation when transmitted over long distances, reducing measurement accuracy. But in the short distance measurement or regular measurement, this 1 effect can be ignored.

Passive probes have many advantages in measuring power supply ripple. Its high-frequency response capability, non-interference to the circuit under test, compact and lightweight design, and relatively low cost make it an ideal choice for measuring power ripple. When selecting test equipment, we also need to consider factors such as specific test requirements, test environment, and accuracy requirements.