AIC1740
Low Output Voltage, 500mA Low Dropout
Linear Regulator
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FEATURES
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DESCRIPTION
The AIC1740 is a 3-pin low dropout linear
regulator. The superior characteristics of the
AIC1740 include zero base current loss, very
low dropout voltage, and 2% accuracy output
voltage.
Typical
ground
current
remains
approximately
65µA, from no load to maximum loading
conditions. Dropout voltage is exceptionally low.
Output current limiting and thermal limiting are
built in to provide maximal protection to the
AIC1740 against fault conditions.
The AIC1740 comes in the popular SOT-223,
TO-251 and TO-252 packages.
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Low Dropout Voltage of 900mV at 500mA
Output Current (3.0V Output Version).
Guaranteed 500mA Output Current.
Internal 1.5Ω P-MOSFET Draws no Base
Current.
Low Ground Current at 65µA.
2% Accuracy Output Voltage of 1.8V/ 2.0V/
2.5V/ 2.7V/ 3.0V.
Input Voltage Range up to 12V.
Needs only 4.7µF for Stability.
Current and Thermal Limiting.
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APPLICATIONS
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Voltage Regulator for CD-ROM Drivers.
Voltage Regulator for LAN Cards.
Voltage Regulator for Monitor Microprocessor.
Voltage Regulator for RAM Module.
Wireless Communication Systems.
Battery Powered Systems.
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TYPICAL APPLICATION CIRCUIT
VIN
V
I N
VOUT
AIC1740
V
OUT
+
1
µ
F
C
I N
GND
+
10
µ
F
C
OUT
Low Dropout Linear Regulator
Analog Integrations Corporation
DS-1740-00 Aug 2, 00
4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC
TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
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AIC1740
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ORDERING INFORMATION
AIC1740-XCX
PACKAGING TYPE
E: TO-252
F: TO-251
Y: SOT-223
OUTPUT VOLTAGE
18: 1.8V
20: 2.0V
25: 2.5V
27: 2.7V
30: 3.0V
ORDER NUMBER
AIC1740-18CE
AIC1740-20CE
AIC1740-25CE
AIC1740-27CE
AIC1740-30CE
(TO-252)
AIC1740-18CF
AIC1740-20CF
AIC1740-25CF
AIC1740-27CF
AIC1740-30CF
(TO-251)
PIN CONFIGURATION
FRONT VIEW
1: VOUT
2: GND
3: VIN
1 2 3
FRONT VIEW
1: VOUT
2: GND
3: VIN
1 2 3
AIC1740-18CY
AIC1740-20CY
AIC1740-25CY
AIC1740-27CY
AIC1740-30CY
(SOT-223)
FRONT VIEW
1: VOUT
2: GND
3: VIN
1
2
3
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ABSOLUTE MAXIMUM RATINGS
Input Supply Voltage
...................................… … … … ....................................
-0.3~12V
.......… … … ..............................
-40°C~ 85°C
Operating Junction Temperature Range
Storage Temperature Range
.........................… … … … ..........................
-65°C~150°C
Power Dissipation
....… … … … … … … … … … … … … ..… … … … … ..… … ...............
0.85W
Thermal Resistance
θ
JC
TO-251, TO-252 Package
....… … .… … ..........
12.5°C/W
SOT-223 Package
....… … … … ..… … … .............15°C/W
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TEST CIRCUIT
Refer to the TYPICAL APPLICATION CIRCUIT
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AIC1740
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ELECTRICAL CHARACTERISTICS
(Ta=25°C, C
IN
=1µF, C
OUT
=10µF, unless otherwise
specified.)
PARAMETER
Output Voltage
No Load
AIC1740-30
AIC1740-27
AIC1740-25
AIC1740-20
AIC1740-18
(Note 1)
TEST CONDITIONS
V
IN
=4.0~12V
V
IN
=4.0~12V
V
IN
=4.0~12V
V
IN
=4.0~12V
V
IN
=4.0~12V
MIN.
2.940
2.646
2.450
1.960
1.764
TYP.
3.0
2.7
2.5
2.0
1.8
50
MAX.
3.060
2.754
2.550
2.040
1.836
UNIT
V
Output Voltage
Temperature
Coefficiency
Line Regulation
Load Regulation
(Note 2)
Current Limit
(Note 3)
Dropout Voltage
(Note 4)
PPM/°C
I
L
=1mA, V
IN
=4.0~12V
V
IN
=5V, I
L
=0.1~500mA
V
IN
=5V, V
OUT
=0V
AIC1740s
AIC1740-30
AIC1740-27
AIC1740-25
AIC1740-20
AIC1740-18
I
L
=0.1mA
I
L
=500mA
3
20
650
0.2
900
950
1000
1260
1370
10
1050
1100
1150
1410
1520
10
50
mV
mV
mA
mV
mV
Ground Current
I
O
=0.1mA~I
MAX
, V
IN
=4V~12V
65
90
µA
Note 1: Guaranteed by design.
Note 2: Regulation is measured at constant junction temperature, using pulse testing with a low ON time.
Note 3: Current limit is measured by pulsing a short time.
Note 4: Dropout voltage is defined as the input to output differential at which the output voltage drops 100mV
below the value measured with a 1V differential.
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AIC1740
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TYPICAL
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0 0
50
100
PERFORMANCE CHARACTERISTICS
Dropout Voltage vs Load Current
V
OUT
=1.8V
V
OUT
=2.0V
V
OUT
C
OUT
=1
µ
F
V
OUT
=3.0V
200mV/DIV
Load Transient Response
Dropout Voltage (mV)
V
OUT
=2.5V
V
OUT
=2.7V
V
OUT
=3.0V
I
OUT
I
OUT
=0.1mA
I
OUT
=250mA
150
200
250
300
350
400
450
500
Load Current (mA)
Time (0.5mS/DIV)
Load Transient Response
C
OUT
=10
µ
F
V
OUT
=3.0V
V
OUT
50mV/DIV
V
IN
V
IN
=4.0V
C
OUT
=1
µ
F
I
L
=1mA
Line Transient Response
V
IN
=6V
I
OUT
=250mA
I
OUT
I
OUT
=0.1mA
V
OUT
V
OUT
=3.0V
20mV/DIV
Time (0.25mS/DIV)
Time (1mS/DIV)
Recommended Max. Output Current vs Input Voltage
600
550
500
Output Current (mA)
450
400
350
300
250
200
150
100
50
0
3
4
5
6
7
8
9
10
11
12
3.0V
1.8V
2.0V
2.7V
2.5V
Input voltage (V)
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AIC1740
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BLOCK DIAGRAM
VIN
VOUT
CURRENT
LIMITING
ERROR
AMP
-
+
-
+
THERMAL
SHUTDOWN
1.235V
Reference
GND
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PIN DESCRIPTION
VOUT PIN - Output pin.
GND PIN - Power GND.
VIN PIN - Power Supply Input.
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APPLICATION INFORMATIONS
A 4.7µF (or greater) capacitor is required between
the AIC1740 output and ground for stability.
Without this capacitor the part will oscillate. Even
though most types of capacitor may work, the
equivalent series resistance (ESR) should be held
to 5Ω or less if Aluminum electrolytic type is used.
Many Aluminum electrolytics have electrolytes that
freeze at about -30°C, so solid tantalums are
A 0.1µF capacitor (or greater) should be placed
from the AIC1740 input to ground if the lead
inductance between the input and power source
exceeds 500nH (approximately 10 inches of trace).
recommended for operation below -25°C. The
value of this capacitor may be increased without
limit.
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