TK112xxB
DEFINITION AND EXPLANATION OF TECHNICAL TERMS
OUTPUT VOLTAGE (V
OUT
)
The output voltage is specified with V
IN
= (V
OUT(TYP)
+ 1 V)
and I
OUT
= 30 mA.
DROPOUT VOLTAGE (V
DROP
)
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.
OUTPUT CURRENT (I
OUT(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 I
OUT
= 30 mA. The input
voltage is set to V
OUT
+1 V, and the current is pulsed to
minimize temperature effect.
CONTINUOUS OUTPUT CURRENT (I
OUT
)
Normal operating output current. This is limited by package
power dissipation.
PULSE OUTPUT CURRENT (I
OUT(PULSE)
)
Maximum pulse width 5 ms at V
OUT
upper 2.0 V; 7 ms. at
V
OUT
under 1.9 V; duty cycle 12.5%: pulse load only.
LINE REGULATION (Line Reg)
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 V
IN
= V
OUT(TYP)
+ 1 V to V
IN
= V
OUT(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 V
IN
= V
OUT
+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.
QUIESCENT CURRENT (I
Q
)
The quiescent current is the current which flows through
the ground terminal under no load conditions (I
OUT
= 0 mA).
GROUND CURRENT (I
GND
)
Ground current is the current which flows through the
ground pin(s). It is defined as I
IN
- I
OUT
, excluding I
CONT
.
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 V
IN
= V
OUT
+ 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.
STANDBY CURRENT (I
STBY
)
Standby current is the current which flows into the regulator
when the output is turned off by the control function
(V
CONT
= 0 V). It is measured with V
IN
= 8 V (9 V for the 8
V output device).
SENSOR CIRCUITS
Overcurrent Sensor
The overcurrent sensor protects the device in the event
that the output is shorted to ground.
Thermal Sensor
The thermal sensor protects the device in the event that
the junction temperature exceeds the safe value (T
J
= 150
°C).
This temperature rise can be caused by external heat,
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
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.
October 1999 TOKO, Inc.
Page 13
TOKO [ TOKO, INC ]
