NCP605, NCP606
http://onsemi.com
9
DEFINITIONS
General
All measurements are performed using short pulse low
duty cycle techniques to maintain junction temperature as
close as possible to ambient temperature.
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 techniques such that the
average junction temperature is not significantly affected.
Load Regulation
The change in output voltage for a change in output load
current at a constant temperature.
Dropout Voltage
The input to output differential at which the regulator
output no longer maintains regulation against further
reductions in input voltage. Measured when the output drops
100 mV below its nominal value. The junction temperature,
load current, and minimum input supply requirements affect
the dropout level.
Ground and Disable Currents
Ground Current is the current that flows through the
ground pin when the regulator operates without a load on its
output (I
GND
). This consists of internal IC operation, bias,
etc. It is actually the difference between the input current
(measured through the LDO input pin) and the output load
current. If the regulator has an input pin that reduces its
internal bias and shuts off the output (enable/disable
function), this term is called the disable current (I
DIS
).
Current Limit and Short Circuit Current Limit
Current Limit is value of output current by which output
voltage drops by 10% with respect to its nominal value.
Short Circuit Current Limit is output current value
measured with output of the regulator shorted to ground.
PSRR
Power Supply Rejection Ratio is defined as ratio of output
voltage and input voltage ripple. It is measured in decibels
(dB).
Output Noise Voltage
This is the integrated value of the output noise over a
specified frequency range. Input voltage and output load
current are kept constant during the measurement. Results
are expressed in mV
rms
or nV / √Hz.
Turn−on and Turn−off Times
Turn−on Time is time difference measured during
power−up of the device from the moment when input
voltage reaches 90% of its operating value to the moment
when output voltage reaches 90% of its nominal value at
specific output current or resistive load.
Turn−off Time is time difference measured during
power−down of the device from the moment when input
voltage drops to 10% of its operating value to the moment
when output voltage drops to 10% of its nominal value at
specific output current or resistive load.
Enable and Disable Times
Enable Time is time difference measured during
power−up of the device from the moment when enable
voltage reaches 90% of input voltage operating value to the
moment when output voltage reaches 90% of its nominal
value at specific output current or resistive load.
Disable Time is time difference measured during
power−down of the device from the moment when enable
voltage drops to 10% of input voltage operating value to the
moment when output voltage drops to 10% of its nominal
value at specific output current or resistive load.
Line Transient Response
Typical output voltage overshoot and undershoot response
when the input voltage is excited with a given slope.
Load Transient Response
Typical output voltage overshoot and undershoot
response when the output current is excited with a given
slope between no−load and full−load conditions.
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 175°C,
the regulator turns off. This feature is provided to prevent
failures from accidental overheating.
Maximum Package Power Dissipation
The power dissipation level at which the junction
temperature reaches its maximum operating value.
