From 2A to 8A Schottky, the business in the two regions is usually a relatively small average current. The larger diode causes additional transmission loss due to its large knot capacitance. CIN and COUT selection In the continuous mode, the source current N -channel MOSFET on each top is a square wave of the duty cycle/vin. Low ESR input capacitors suitable for maximum average root values must be used. The details of the closed equation can be found in the application annotation 77. Figure 6 shows the relationship between the input -electrode wave current of different phase configurations and the output voltage and the input voltage. Input ripple current and DC output current. This picture can be used to replace boring calculations. The minimum input ripple current as phase and output voltage n (vout) are equal to the input voltage vin or:
So you can select the phase number to minimize the input and input and the input and input and The capacitor size of the output voltage. In the chart in FIG. 4, the largest local input RMS reaches the capacitor current in the following situations:
These worst cases are usually used for DE SIGN, because even significant is significant, even if it is significant, it is significant. The deviation will not provide too much liberation. Note that the ripple current rating of the capacitor manufacturer is usually based on the life of
2000 . This suggestion further reduces the rated capacity of the capacitor or selects a capacitor with a rated temperature higher than the required capacitor. Several capacitors can also be parallel to meet the size or height requirements in the design. There are always any problems with the capacitor manufacturer. Figure 6 shows that the peak input current is reduced linearly, which is used in contrast to N. It is important to notice that the loss of the losses and the input uniformly root current is proportional. As a result, the realization of the three stages can reduce the power loss of 90%compared with the single -phase design. The battery/input protection fuse resistance (if used), PC board traces and connector resistance loss also reduced the input ripple current multi -phase system. Due to the effective increase of current pulse frequency.
Ceramic capacitors should pay attention to the following points when designing.
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