ncp623mn-40r2 ON Semiconductor, ncp623mn-40r2 Datasheet - Page 5

• Manufacturer Part Number: ncp623mn-40r2
• Description: 150 Ma, Ultra Low Noise, Ldo Voltage Regulator With On/off Control
• Manufacturer: ON Semiconductor

change in load current at constant chip temperature.
the regulator output no longer maintains regulation against
further reductions in input voltage. Measured when the
output drops 100 mV below its nominal value (which is
measured at 1.0 V differential), dropout voltage is affected
by junction temperature, load current and minimum input
supply requirements.
output with a constant load and no input ripple, measured
over a specified frequency range.
dissipation for which the regulator will operate within
specifications.
regulator chip and is not delivered to the load.
change in the input voltage. The measurement is made under
conditions of low dissipation or by using pulse techniques
such that the average chip temperature is not significantly
affected.
undershoot response when input voltage is excited with a
given slope.
circuitry is provided to protect the integrated circuit in the
event that the maximum junction temperature is exceeded.
When activated, typically 150°C, the regulator turns off.
This feature is provided to prevent catastrophic failures from
accidental overheating.
Load Regulation − The change in output voltage for a
Dropout Voltage − The input/output differential at which
Output Noise Voltage − The RMS AC voltage at the
Maximum Power Dissipation − The maximum total
Quiescent Current − Current which is used to operate the
Line Regulation − The change in input voltage for a
Line Transient Response − Typical over− and
Thermal Protection − Internal thermal shutdown
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DEFINITIONS
5
package power dissipation is the power dissipation level at
which the junction temperature reaches its maximum value
i.e. 125°C. The junction temperature is rising while the
difference between the input power (V
output power (V
calculate the maximum power dissipation, maximum load
current or maximum input voltage (see Application Hints:
Protection).
is a lot increased when using appropriate application design.
Mounting pad configuration on the PCB, the board material
and also the ambient temperature are affected the rate of
temperature rise. It means that when the I
conductivity through PCB, the junction temperature will be
“low” even if the power dissipation is great.
evaluated by deliberately activating the thermal shutdown
of the circuit (by increasing the output current or raising the
input voltage for example).
subtracting the output power from the input power. All
variables are then well known: power dissipation, thermal
shutdown temperature (150°C for NCP623) and ambient
temperature.
Maximum Package Power Dissipation − The maximum
Depending on ambient temperature, it is possible to
The maximum power dissipation supported by the device
The thermal resistance of the whole circuit can be
Then you can calculate the power dissipation by
out
X I
out
) is increasing.
CC
C
has good thermal
X I
CC
) and the