TK112xxB
DEFINITION AND EXPLANATION OF TECHNICAL TERMS
QUIESCENT CURRENT (IQ)
OUTPUT VOLTAGE (VOUT
)
The quiescent current is the current which flows through
thegroundterminalundernoloadconditions(IOUT =0mA).
The output voltage is specified with VIN = (VOUT(TYP) + 1 V)
and IOUT = 30 mA.
DROPOUT VOLTAGE (VDROP
)
GROUND CURRENT (IGND
)
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.
Ground current is the current which flows through the
ground pin(s). It is defined as IIN - IOUT, excluding ICONT
.
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 100 mVrms, 400 Hz superimposed on the
input voltage, where VIN = VOUT + 1.5 V. The output
decoupling capacitor is set to 10 µF, the noise bypass
capacitor is set to 0.1 µF, and the load current is set to 30
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)
)
This is the maximum continuous output current specified
under the condition where the output voltage drops 0.3 V
below the value specified with IOUT = 30 mA. The input
voltage is set to VOUT +1 V, and the current is pulsed to
minimize temperature effect.
STANDBY CURRENT (ISTBY
)
CONTINUOUS OUTPUT CURRENT (IOUT
)
Standbycurrentisthecurrentwhichflowsintotheregulator
when the output is turned off by the control function
(VCONT = 0 V). It is measured with VIN = 8 V (9 V for the 8
V output device).
Normaloperatingoutputcurrent.Thisislimitedbypackage
power dissipation.
PULSE OUTPUT CURRENT (IOUT(PULSE)
)
SENSOR CIRCUITS
Overcurrent Sensor
Maximum pulse width 5 ms at VOUT upper 2.0 V; 7 ms. at
VOUT under 1.9 V; duty cycle 12.5%: pulse load only.
LINE REGULATION (Line Reg)
The overcurrent sensor protects the device in the event
that the output is shorted to ground.
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.
Thermal Sensor
The thermal sensor protects the device in the event that
the junction temperature exceeds the safe value (TJ = 150
°C). Thistemperaturerisecanbecausedbyexternalheat,
excessive power dissipation caused by large input to
output voltage drops, or excessive output current. The
regulator will shut off when the temperature exceeds the
safe value. As the junction temperatures decrease, the
regulatorwillbegintooperateagain. Undersustainedfault
conditions, the regulator output will oscillate as the device
turns off then resets. Damage may occur to the device
under extreme fault conditions.
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 +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.
October 1999 TOKO, Inc.
Page 13
TOKO [ TOKO, INC ]
