Buck Converters |
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Buck Converters |
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 Buck Converter
This topology is usually used as an on-board regulator. Its failings are two: 1)Pulsating input currents send too much noise back to the source. If there are multiple post-regulators, the switching noise from each becomes a line disturbance problem for the rest. 2)The unity ratio between relative power loop gain and line to output gain makes good line regulation impossible. This means that step line rejection (large signal) is limited to a factor of 1/2 => -6dB. Thus a 100% to 0% to 100% line dropout, e.g. from wiggling a connector, produces an unacceptable +/-25% excursion at the output.   Buck with Input Filter
Here, the line noise problem is solved, but the line regulation problem remains. As before, there is not enough power loop gain to adequately reduce line transients. Rejection of line disturbances is poor. Increasing the loop gain to improve line rejection still leads to duty cycle saturation (D = Dmin or D = 0,) and loss of regulation. | Buck Converters | Boost Converters | Buckboost Converters | Further Converters | | The Four Topologies | Other Topologies | Philosophy of Design | Do the Math | | Return Home | Old Home | |
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