Problems that will be ignored in power module customization

Power module customizationIt is a higher requirement for power modules. For customers with more functions and higher requirements, power module customization is definitely a good choice. The following editor wants to tell you about the problems that power module customization will ignore!

Output noise measurement;

Magnetic system design;

Synchronous buck converter failure;

Reliability of printed circuit boards.

These problems will be discussed below, as well as various simple techniques to solve these problems.

Power module customized output noise measurement technology

All power supplies have switch-mode output noise. The higher the switching frequency, the correct measurement technique is needed to ensure that the measurement data is accurate and reliable. To measure output noise and other important data, you can use Tektronix probe probes (commonly known as cold nozzle probes) to ensure that the measured data is accurate, reliable and predictable. This measurement technique also ensures that the ground loop is minimized.

We must also calculate the propagation delay of the measuring instrument. Most current probes have a propagation delay greater than that of a voltage probe. Measurements where both voltage and current waveforms must be displayed at the same time cannot ensure the accuracy of the measurement graph unless the delay uses human balance.

The current probe will also be induced into the circuit. A typical current probe will enter a 600nH inductor. For high-frequency circuit design, since the circuit can withstand the inductance of no more than 1mH, inputting the inductance through the probe will affect the accuracy of di/dt current measurement, and even cause large errors in the measurement numbers. If the inductor is saturated, another more accurate method can be used to measure the amount of current. For example, we can measure the voltage of a small shunt resistor in series with the inductor.

Design of magnetics for power module customization

Whether the magnetic core is reliable is another question that is often overlooked. Most output inductors use iron powder cores, because iron powder is a lower cost material. Approximately 95% of the components of the iron powder core are pure iron particles, and these iron powder particles are glued together with an organic glue. These glue pads also separate each iron powder particle, so that the magnetic core is filled with the transparent control room inside and outside.

The breakdown phenomenon of the synchronous buck converter customized by the power module

Power supply systems such as point-of-load power supply systems (POL) or point-of-use power supply systems (PUPS) have widely adopted synchronous step-down converters (Figure 3). This synchronous buck converter uses high-end and low-end MOSFETs to replace the clamping diodes of the traditional buck converters in order to reduce the loss of load current.

Reliability of power module customization

Any module must pass rigorous testing in the early stage to ensure that the design is complete and reliable, so as to avoid unexpected problems in the later stages of the production process. The relevant modules must be able to be tested in the customer's system to ensure that all related factors that may cause system failures, such as cooling fan failure, intermittent cooling fan stalls, etc., can be fully considered. Engineers who adopt a decentralized structure hope that the designed system can be used continuously for many years with little or no failure.