UNISONIC TECHNOLOGIES CO., LTD
LR1108
1A FAST ULTRA LOW
DROPOUT LINEAR
REGULATOR
DESCRIPTION
The UTC
LR1108
operate from a +2.5V ~ +7.0V input supply as
fast ultra low-dropout linear regulators. The range of preset output
voltage options are wide availably. To make themselves suitable
for low voltage microprocessor applications, these ultra low dropout
linear regulators respond very fast to step changes in load. The
UTC
LR1108
allows low quiescent current operation independent
of output load current cause they are developed on a CMOS
process. UTC
LR1108
can operate under extremely low dropout
conditions also cause the CMOS process.
The UTC
LR1108
have ultra low dropout voltage; 300mV at 1A
load current typically.
The Ground Pin Current is Typically 200uA at 1mA load current.
ERROR Flag: When the output voltage drops 10% below
nominal value Error flag goes low.
Output Voltage Precision: Multiple output voltage options are
available, and are ranging from 1.2V ~ 5.0V, at room temperature
with a guaranteed accuracy of ±1.5%, and ±3.0% when varying
line, load, and temperature.
2
1
CMOS IC
3
1
2
SOT-23
3
5
4
SOT-25
*Pb-free plating product number: LR1108L
FEATURES
* Dropout voltage is ultra low
* Ground pin current is low
* Load regulation of 0.04%
* The guaranteed output current is 1A DC
* Accuracy output voltage is ± 1.5%
* ERROR flag indicates output status
* Extremely low output capacitor required
* Overtemperature protection and overcurrent protection
ORDERING INFORMATION
Ordering Number
Normal
Lead Free Plating
LR1108-xx-AE3-3-R
LR1108L-xx-AE3-3-R
LR1108-xx-AF5-R
LR1108L-xx-AF5-R
Package
SOT-23
SOT-25
1
O
I
Pin Assignment
2
3
4
G
I
-
G SD ERROR
5
-
O
Packing
Tape Reel
Tape Reel
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LR1108
MARKING INFORMATION
PACKAGE
VOLTAGE CODE
PIN 1
PIN 2
PIN 3
PIN 4
PIN 5
CMOS IC
MARKING
SOT-23
15 :1.5V
18:1.8V
25:2.5V
2J:2.85V
33:3.3V
SOT-25
V
OUT
GND
V
IN
-
-
3
2
1
V
IN
GND
SD
ERROR
V
OUT
SPXX
Lead Plating
4
5
PIN DESCRIPTION
Pin Description for SOT-23 Packag
e
PIN NO PIN NAME
I/O
DESCRIPTION
1
V
OUT
O
Output Voltage
2
GND
Ground
3
V
IN
Input Supply
Pin Description for SOT-25 Package
PIN NO
PIN NAME
I/O
DESCRIPTION
1
V
IN
Input Supply
2
GND
Ground
3
SD
I
Shutdown
4
ERROR
O
ERROR Flag
5
V
OUT
O
Output Voltage
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LR1108
BLOCK DIAGRAM
V
IN
CMOS IC
SD
V
OUT
ERROR
GND
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LR1108
ABSOLUTE MAXIMUM RATINGS
CMOS IC
PARAMETER
SYMBOL
RATINGS
UNIT
Input Voltage (Operating), (Note 11)
2.5~7.0
V
V
IN
Input Voltage (Survival)
-0.3~+7.5
V
Shutdown Input Voltage
V
IN(SHDN)
-0.3~V
IN
+0.3
V
Output Voltage (Survival), (Note 5), (Note 6)
V
OUT
-0.3~+7.5
V
I
OUT
(Survival)
Short Circuit Protected
Maximum Voltage for ERROR Pin
V
IN
+0.3
V
Maximum Operating Current (DC)
1
A
Power Dissipation (Note 2)
P
D
Internally Limited
ESD Rating (Note 3)
2
kV
Junction Temperature
T
J
+125
℃
Operating Temperature
T
OPR
-40~+125
℃
Storage Temperature
T
STG
-65~+150
℃
Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
ELECTRICAL CHARACTERISTICS
Limits in standard typeface are for T
J
= 25°C, and limits in
boldface type
apply over the full operating temperature
range.
(T
J
= 25℃, V
IN
= V
O(NOM)
+ 1V, I
L
= 10 mA, C
OUT
= 2.2µF, V
SD
= V
IN
-0.3V, unless otherwise specified.)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
0 mA
≤
I
L
≤
1A
-1.5
+1.5
Output Voltage Tolerance (Note 7)
V
OUT
0
%
-3
+3
V
OUT
+1
≤
V
IN
≤
7.0V
Output Voltage Line Regulation (Note 7)
△
V
OUT
V
OUT
+1V<V
IN
<7.0V
0.05
%
Output Voltage Load Regulation (Note 7)
△
V
OUT
/
△
I
OUT
10 mA < I
L
< 1A
0.04
%
Dropout Voltage (Note 9)
V
D
I
L
= 1A
300
500
mV
Ground Pin Current In Normal Operation
I
L
= 0 mA
200
I
GND
uA
Mode
I
L
= 1A
300
Peak Output Current
I
O(PEAK)
(Note 2)
600
800
mA
SHORT CIRCUIT PROTECTION
Short Circuit Current
I
SC
2
A
OVER TEMPERATURE PROTECTION
Shutdown Threshold
T
SHDN(THR)
165
℃
Thermal Shutdown Hysteresis
T
SHDN(HYS)
10
℃
SHUTDOWN INPUT
Output = High
V
IN
-0.3
V
IN
Shutdown Threshold
V
SHDN
V
Output = Low
0
0.2
Turn-off Delay
t
D(OFF)
I
L
= 1A
20
µs
Turn-on Delay
t
D(ON)
I
L
= 1A
25
µs
SD Input Current
I
SD
V
SD
= V
IN
1
nA
ERROR FLAG COMPARATOR
ERROR Flag Saturation
V
EF(SAT)
I
SINK
= 100µA
0.02
0.1
V
ERROR Flag Pin Leakage Current
I
I(LEAK)
1
nA
Threshold
V
T
(Note 8)
5
10
16
%
Threshold Hysteresis
V
THR
(Note 8)
2
5
8
%
Flag Reset Delay
t
D
1
µs
AC PARAMETERS
V
IN
= V
OUT
+ 1.5V
60
C
OUT
=100uF, V
OUT
= 3.3V
dB
Ripple Rejection
PSRR
V
IN
= V
OUT
+ 0.3V
40
C
OUT
=100uF, V
OUT
= 3.3V
Output Noise Density
ρ
n(l/f)
f = 120Hz
0.8
µV
BW = 10Hz – 100kHz
150
Output Noise Voltage
eN
µVrms
BW = 300Hz – 300kHz
100
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LR1108
ELECTRICAL CHARACTERISTICS(Cont.)
CMOS IC
Note 1. Limits beyond which damage to the device may occur is indicated by absolute maximum ratings. Conditions
for which the device is intended to be functional is indicated by operating ratings, but specific performance
limits isn’t be guaranteed. To make sure of specifications and test conditions, read Electrical Charateristics.
Only for the test conditions listed the guaranteed specifications can be applied. When the device is not
operated under the listed test conditions some performance characteristics may degrade.
2. Devices must be derated based on package thermal resistance at elevated temperatures.
3. Which discharged through a 1.5kΩ resistor into each pin is a 100pF capacitor in the human body model.
4. The most likely parametric norm represents at 25℃.
5. The LR1108 output must be diode-clamped to ground. If used in a dual-supply system where the regulator
load is returned to a negative supply.
6. Between the V
IN
and V
OUT
terminals the output PMOS structure contains a diode. This diode is reverse
biased normally. If the voltage at the output terminal is forced to be higher than the voltage at the input
terminal this diode will get forward biased. This diode can withstand 1Amp of peak current and 200mA of DC
current typically.
7. Output voltage line regulation is the change in output voltage from the nominal value which is due to change
in the input line voltage. Which is defined as the change in output voltage from the nominal value due to
change in load current is output voltage load regulation. The load regulation and line regulation specification
include the typical number only. But, the limits for load and line regulation are included in the output voltage
tolerance specification.
8. Error Flag hysteresis and threshold are specified as regulated output voltage’s percentage.
9. At which the output drops 2% below the normal value dropout voltage is defined as the minimum input to
output differential voltage. Only to output voltages of 2.5V and above dropout voltage specification applies.
For output voltages below 2.5V, since the minimum input voltage is 2.5V, the drop-out voltage is nothing but
the input to output differential.
10. Specification has been tested at
−40℃ ≤
T
J
≤
85℃cause under shutdown conditions the temperature rise of
the device is negligible.
11. The minimum operating V
IN
value is equal to [V
OUT(NOM)
+ V
DROPOUT
] or 2.5V, just the greater.
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QW-R102-031.A
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