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Chapter 6
With an LDO, the difference between input voltage and output voltage must be small, and
the output v
oltage must be tightly regulated. In addition, transient response must be fast
enough to handle loads that can go from zero to tens of milleamperes in nanoseconds.
Also, output voltage can vary due to changes in input voltage, output load current, and
temperature. Primarily, these output variations are caused by the effects of temperature
on LDO voltage reference, error amplifi er, and its sampling resistors R
1
and R
2
.
LDOs provide either an adjustable or fi xed-output voltage. Fixed-output types exhibit
output ...