NCP551, NCV551
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5
DEFINITIONS
Load Regulation
The change in output voltage for a change in output
current at a constant temperature.
Dropout Voltage
The input/output differential at which the regulator output
no longer maintains regulation against further reductions in
input voltage. Measured when the output drops 3% below its
nominal. The junction temperature, load current, and
minimum input supply requirements affect the dropout level.
Maximum Power Dissipation
The maximum total dissipation for which the regulator
will operate within its specifications.
Quiescent Current
The quiescent current is the current which flows through
the ground when the LDO operates without a load on its
output: internal IC operation, bias, etc. When the LDO
becomes loaded, this term is called the Ground current. It is
actually the difference between the input current (measured
through the LDO input pin) and the output current.
Line Regulation
The change in output voltage for a change in input voltage.
The measurement is made under conditions of low
dissipation or by using pulse technique such that the average
chip temperature is not significantly affected.
Line Transient Response
Typical over and undershoot response when input voltage
is excited with a given slope.
Thermal Protection
Internal thermal shutdown circuitry is provided to protect
the integrated circuit in the event that the maximum junction
temperature is exceeded. When activated at typically 160°C,
the regulator turns off. This feature is provided to prevent
failures from accidental overheating.
Maximum Package Power Dissipation
The maximum power package dissipation is the power
dissipation level at which the junction temperature reaches
its maximum operating value, i.e. 125°C. Depending on the
ambient power dissipation and thus the maximum available
output current.
