TK111xxM
DEFINITION AND EXPLANATION OF TECHNICAL TERMS
thegroundterminalundernoloadconditions(IOUT =0mA).
OUTPUT VOLTAGE (VOUT
)
GROUND CURRENT
The output voltage is specified with VIN = (VOUT(TYP) + 1 V)
and IOUT = 10 mA.
Ground current is the current which flows through the
ground pin(s). It is defined as IIN - IOUT, excluding control
current.
DROPOUT VOLTAGE (VDROP
)
The dropout voltage is the difference between the input
voltage and the output voltage at which point the regulator
starts to fall out of regulation. Below this value, the output
voltage will fall as the input voltage is reduced. It is
dependent upon the load current and the junction
temperature.
RIPPLE REJECTION RATIO (RR)
Ripple rejection is the ability of the regulator to attenuate
the ripple content of the input voltage at the output. It is
specified with 200 mVrms, 1 kHz superimposed on the
inputvoltage,whereVIN =VOUT+2V.Theoutputdecoupling
capacitor is set to 4.7 µF, the noise bypass capacitor is set
to 0.01 µF, 0.1 µF, 1.0 µF and the load current is set to
10 mA. Ripple rejection is the ratio of the ripple content of
the output vs. the input and is expressed in dB.
OUTPUT CURRENT (IOUT(MAX)
)
The rated output current is specified under the condition
where the output voltage drops 0.3 V below the value
specified with IOUT = 10 mA. The input voltage is set to
VOUT +1V,andthecurrentispulsedtominimizetemperature
effect.
Example: 64 dB at CN = 0.01 µF, 70 dB at
CN = 0.1 µF, 74 dB at CN = 1.0 µF
CONTINUOUS OUTPUT CURRENT (IOUT
)
SENSOR CIRCUITS
Overcurrent Sensor
Normal operating output current. This is limited by the
package power dissipation.
The overcurrent sensor protects the device if the output is
shorted to ground.
PULSE OUTPUT CURRENT (IOUT (PULSE)
)
Max pulse width 5 ms, Duty cycle 12.5%: pulse load only.
Thermal Sensor
LINE REGULATION (Line Reg)
The thermal sensor protects the device if the junction
temperature exceeds the safe value (Tj = 150 °C). This
temperaturerisecanbecausedbyextremeheat,excessive
power dissipation caused by large output voltage drops, or
excessive output current. The regulator will shut off when
the temperature exceeds the safe value. As the junction
temperature decreases, the regulator will begin to operate
again. Under sustained fault conditions, the regulator
output will oscillate as the device turns off then resets.
Damage may occur to the device under extreme fault
conditions.
Line regulation is the ability of the regulator to maintain a
constant output voltage as the input voltage changes. The
line regulation is specified as the input voltage is changed
from VIN = VOUT(TYP) + 1 V to VIN = VOUT(TYP) + 6 V.
LOAD REGULATION (Load Reg)
Load regulation is the ability of the regulator to maintain a
constant output voltage as the load current changes. It is
a pulsed measurement to minimize temperature effects
with the input voltage set to VIN = VOUT(TYP) +1 V. The load
regulation is specified under two output current step
conditions of 1 mA to 60 mA and 1 mA to 100 mA.
Reverse Voltage Protection
Reverse voltage protection prevents damage due to the
output voltage being higher than the input voltage. This
faultconditioncanoccurwhentheoutputcapacitorremains
charged and the input is reduced to zero, or when an
QUIESCENT CURRENT (IQ)
The quiescent current is the current which flows through
March 1999 TOKO, Inc.
Page 9
TOKO [ TOKO, INC ]
