How to Measure the Loss of Switching Power Supply Power with a Digital Oscilloscope
With the increasing demand for switching power supplies in many industries, it is crucial to measure and analyze the power loss of the next generation of switching power supplies. In this application field, TDS5000 or TDS7000 series digital fluorescence oscilloscopes, combined with TDSPWR2 power measurement software, can help you easily complete the required measurement and analysis tasks.
The new SMPS (Switch Mode PowerSupply) architecture requires high current and low voltage for processors with high data speed and GHz level, which adds intangible new pressure to power device designers in terms of efficiency, power density, reliability, and cost. In order to consider these requirements in the design, the designers adopted new architectures such as synchronous rectification technology, active power filter correction, and increasing switching frequency. These technologies also bring some higher challenges, such as high power losses, thermal dissipation, and excessive EMI/EMC on switching devices.
During the transition from "off" (conduction) to "on" (off) state, the power supply unit will experience high power losses. The power loss of switching devices in the "on" or "off" state is relatively small because the current passing through the device or the voltage on the device is very small. Inductors and transformers can isolate the output voltage and smooth the load current. Inductors and transformers are also susceptible to the influence of switching frequency, leading to power dissipation and occasional faults caused by saturation.
Due to the dissipated power within the switching power supply device, the overall efficiency of the thermal effect of the power supply is determined. Therefore, measuring the power loss of the switching device and inductor/transformer is an extremely important measurement work. This measurement can measure power efficiency and thermal dissipation.
With the increasing demand for switching power supplies in many industries, it is crucial to measure and analyze the power loss of the next generation of switching power supplies. In this application field, TDS5000 or TDS7000 series digital fluorescence oscilloscopes, combined with TDSPWR2 power measurement software, can help you easily complete the required measurement and analysis tasks.
The new SMPS (Switch Mode PowerSupply) architecture requires high current and low voltage for processors with high data speed and GHz level, which adds intangible new pressure to power device designers in terms of efficiency, power density, reliability, and cost. In order to consider these requirements in the design, the designers adopted new architectures such as synchronous rectification technology, active power filter correction, and increasing switching frequency. These technologies also bring some higher challenges, such as high power losses, thermal dissipation, and excessive EMI/EMC on switching devices.
During the transition from "off" (conduction) to "on" (off) state, the power supply unit will experience high power losses. The power loss of switching devices in the "on" or "off" state is relatively small because the current passing through the device or the voltage on the device is very small. Inductors and transformers can isolate the output voltage and smooth the load current. Inductors and transformers are also susceptible to the influence of switching frequency, leading to power dissipation and occasional faults caused by saturation.
Due to the dissipated power within the switching power supply device, the overall efficiency of the thermal effect of the power supply is determined. Therefore, measuring the power loss of the switching device and inductor/transformer is an extremely important measurement work. This measurement can measure power efficiency and thermal dissipation.
Calculate the power loss of electromagnetic components
Another method that can reduce power loss is related to the magnetic core. From typical AC/DC and DC/DC circuit diagrams, inductors and transformers are other components that dissipate power, thus not only affecting power efficiency but also causing thermal dissipation.
The testing of inductors usually uses LCR. LCR uses a sine wave as the test signal. In a switching power supply device, the inductor will be loaded with high-voltage and high current switching signals, but none of them are sinusoidal signals. Therefore, power device designers need to monitor the behavioral characteristics of inductors or transformers within the actual powered power device. Therefore, testing using LCR may not reflect the actual situation.
The effective method for observing the characteristics of magnetic cores is through the B-H curve, as the B-H curve can quickly reveal the behavioral characteristics of inductors within the power supply device. TDSPWR2 allows you to quickly perform B-H analysis using a laboratory oscilloscope without the need for expensive specialized tools.
During the switching on and steady-state periods of the power supply device, inductors and transformers have different behavioral characteristics. Previously, to view and analyze B-H features, designers had to first capture the signal and then conduct further analysis on a personal PC. Now, you can perform BH analysis directly on the oscilloscope through TDSPWR2 to observe the behavioral characteristics of the inductor in real-time.When conducting in-depth analysis, TDSPWR2 can also provide cursor links between BH plots and captured data on the oscilloscope.
