How to choose the switching power supply frequency?
such as 300KHZ better magnetic material can do 500KHZ or more high. Input voltage and then higher, we need to pay attention to the switch tube switching loss problems, and generally only to do dozens to hundreds of hundreds of KHZ or so. The specific circumstances of the specific analysis, and some soft-switching, resonant what the high-power high-efficiency topology!
Have a few points! The size of the input voltage, the choice of transformer magnetic material, the choice of the main switch tube, there is the overall volume requirements can also be said to want to achieve the power density! For example: low-voltage input, such as 6-160VDC, when the pressure on the tube is not high, the switching loss is not dominant, the frequency can be relatively high,
Since I do not have power, the following is only a personal view
Internal: 1: depends on your topology and power level 2: the choice of IC and switch operating frequency and can withstand the thermal upper limit external: 3: circuit other power device frequency range 4: assigned to the various devices Limit the temperature is acceptable, in terms of volume, efficiency, cost, heat, system stability, etc., the parties weigh the next value, then the frequency of the better the common frequency as small, the corresponding magnetic device volume will be relatively large, and Frequency is large, the device is small, but the switch loss, of course, core loss is also large, unacceptable.
If there are problems please go to the big bit forum to ask me, if you help the busy also hope to adopt the answer!
