tk11633utl Token Electronics Industry Co., Ltd., tk11633utl Datasheet - Page 10

• Manufacturer Part Number: tk11633utl
• Description: Three-terminal Voltage Regulator
• Manufacturer: Token Electronics Industry Co., Ltd.

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
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
regulation is specified under three output current step
conditions of 0 mA to 30 mA, 0 mA to 100 mA and 0 mA to
150 mA.
DROPOUT VOLTAGE (V
This is a measure of how well the regulator performs as the
input voltage decreases. The smaller the number, the
further the input voltage can decrease before regulation
problems occur. Nominal output voltage is first measured
when V
the output voltage has dropped 100 mV from the nominal,
V
by load current and junction temperature.
GROUND CURRENT (I
Ground current is the current which flows through the
ground pin(s). It is defined as I
current.
OUTPUT NOISE VOLTAGE
This is the effective AC voltage that occurs on the output
voltage under the condition where the input noise is low
and with a given load, filter capacitor, and frequency
range.
THERMAL PROTECTION
This is an internal feature which turns the regulator off
when the junction temperature rises above 150 C. After
the regulator turns off, the temperature drops and the
regulator output turns back on. Under certain conditions,
the output waveform may appear to be an oscillation as the
output turns off and on and back again in succession.
TK116xxU
Page 10
IN
- V
IN
OUT
IN
= V
= V
is the dropout voltage. This voltage is affected
OUT(TYP)
OUT(TYP)
DEFINITION AND EXPLANATION OF TECHNICAL TERMS
+ 1 V to V
+ 1 V at a chosen load current. When
GND
DROP
)
IN
)
IN
IN
= V
= V
- I
OUT(TYP)
OUT
OUT(TYP)
, excluding control
+1 V. The load
+ 6 V.
PACKAGE POWER DISSIPATION (P
This is the power dissipation level at which the thermal
sensor is activated. The IC contains an internal thermal
sensor which monitors the junction temperature. When
the junction temperature exceeds the monitor threshold of
150 C, the IC is shut down. The junction temperature
rises as the difference between the input power (V
and the output power (V
temperature is greatly affected by the mounting pad
configuration on the PCB, the board material and the
ambient temperature. When the IC mounting has good
thermal conductivity, the junction temperature will be low,
even if the power dissipation is great. When the radiation
of heat is good, the device temperature will be low, even if
the power loss is great. When mounted on the
recommended mounting pad, the power dissipation of the
SOT-89 package is 1000 mW. Derate the power dissipation
at 8 mW/ C for operation above 25 C. To determine the
power dissipation for shutdown when mounted, attach the
device on the actual PCB and deliberately increase the
output current (or raise the input voltage) until the thermal
protection circuit is activated. Calculate the power
dissipation of the device by subtracting the output power
from the input power. The measurements should allow for
the ambient temperature of the PCB. The value obtained
from P
mounting pad should provide maximum thermal
conductivity in order to maintain low device temperatures.
As a general rule, the lower the temperature, the better the
reliability of the device. The thermal resistance when
mounted is expressed as follows:
For Toko ICs, the internal limit for junction temperature is
150 C. If the ambient temperature (T
P
simple way to determine P
the output side is shorted. Input current gradually falls as
temperature rises. You should use the value when the
D
is the value when the thermal sensor is activated. A
D
T
150 C =
/(150 C - T
j
jA
=
= 125 C/P
jA
x P
jA
D
x P
A
+ T
) is the derating factor. The PCB
D
OUT
D
A
+ 25 C
D
x I
December 1998 TOKO, Inc.
is to calculate V
OUT
) increases. The rate of
A
D
) is 25 C, then:
)
IN
x I
IN
IN
when
x I
IN
)