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We have seen an uptick in the use of linear low drop-out (LDO) regulators. This is not
new technology, but the LDO regulators are getting smaller and having much higher
power supply rejection ratios (PSRRs). We are now seeing vendors such as ADI providing
LDO regulators that have a PSRR of 80 dB in the 100-kilohertz to 1-megahertz range
compared with previous generations, where the PSRR in this range was around 40 dB.
This is a major improvement because that is the range where switching converter ripple
usually lies. Using high-PSRR LDO regulators with much less ripple on the power output
side reduces the need for additional filtering upstream of point-of-load converters.
PDN issues affect the project and schedule. With proper design, you can avoid the
likelihood of a costly respin and the associated schedule hit.
'' PDN issues affect
the project and
schedule. With
proper design,
you can avoid the
likelihood of a
costly respin and
the associated
schedule hit."
