AIC1740
Low Output Voltage, 500mA Low Dropout
Linear Regulator
Analog Integrations Corporation 4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC
www.analog.com.tw
DS-1740-00 Aug 2, 00
TEL: 886-3-5772500 FAX: 886-3-5772510
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FEATURES
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Low Dropout Voltage of 900mV at 500mA
Output Current (3.0V Output Version).
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Guaranteed 500mA Output Current.
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Internal 1.5
P-MOSFET Draws no Base
Current.
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Low Ground Current at 65
A.
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2% Accuracy Output Voltage of 1.8V/ 2.0V/
2.5V/ 2.7V/ 3.0V.
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Input Voltage Range up to 12V.
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Needs only 4.7
F for Stability.
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Current and Thermal Limiting.
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APPLICATIONS
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Voltage Regulator for CD-ROM Drivers.
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Voltage Regulator for LAN Cards.
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Voltage Regulator for Monitor Microprocessor.
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Voltage Regulator for RAM Module.
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Wireless Communication Systems.
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Battery Powered Systems.
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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
65
A, 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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TYPICAL APPLICATION CIRCUIT
+
+
AIC1740
V
OUT
VOUT
GND
VIN
1
F
C
I N
V
I N
10
F
C
OUT
Low Dropout Linear Regulator
AIC1740
2
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ORDERING INFORMATION
ORDER NUMBER
AIC1740-18CE
AIC1740-20CE
AIC1740-25CE
AIC1740-27CE
AIC1740-30CE
(TO-252)
PIN CONFIGURATION
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
AIC1740-XCX
FRONT VIEW
1: VOUT
2: GND
3: VIN
2 3
1
2 3
1
2
3
1
AIC1740-18CF
AIC1740-20CF
AIC1740-25CF
AIC1740-27CF
AIC1740-30CF
(TO-251)
AIC1740-18CY
AIC1740-20CY
AIC1740-25CY
AIC1740-27CY
AIC1740-30CY
(SOT-223)
FRONT VIEW
1: VOUT
2: GND
3: VIN
FRONT VIEW
1: VOUT
2: GND
3: VIN
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ABSOLUTE MAXIMUM RATINGS
Input Supply Voltage
...................................... ... ... ... .................................... -0.3~12V
Operating Junction Temperature Range
.......... ... ... .............................. -40
C~ 85
C
Storage Temperature Range
............................ ... ... ... .......................... -65
C~150
C
Power Dissipation ....... ... ... ... ... ... ... ... ... ... ... ... ... ..... ... ... ... ... ..... ... ............... 0.85W
Thermal Resistance
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
AIC1740
3
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ELECTRICAL CHARACTERISTICS
(Ta=25
C, C
IN
=1
F, C
OUT
=10
F, unless otherwise
specified.)
PARAMETER
TEST CONDITIONS
MIN.
TYP.
MAX.
UNIT
Output Voltage
No Load
AIC1740-30
AIC1740-27
AIC1740-25
AIC1740-20
AIC1740-18
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
2.940
2.646
2.450
1.960
1.764
3.0
2.7
2.5
2.0
1.8
3.060
2.754
2.550
2.040
1.836
V
Output Voltage
Temperature
Coefficiency
(Note 1)
50
PPM/
C
Line Regulation
I
L
=1mA, V
IN
=4.0~12V
3
10
mV
Load Regulation
(Note 2)
V
IN
=5V, I
L
=0.1~500mA
20
50
mV
Current Limit
(Note 3)
V
IN
=5V, V
OUT
=0V
650
mA
AIC1740s
I
L
=0.1mA
0.2
10
mV
Dropout Voltage
(Note 4)
AIC1740-30
AIC1740-27
AIC1740-25
AIC1740-20
AIC1740-18
I
L
=500mA
900
950
1000
1260
1370
1050
1100
1150
1410
1520
mV
Ground Current
I
O
=0.1mA~I
MAX
, V
IN
=4V~12V
65
90
A
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.
AIC1740
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TYPICAL PERFORMANCE CHARACTERISTICS
0
50
100
150
200
250
300
350
400
450
500
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
V
OUT
=3.0V
V
OUT
=2.7V
V
OUT
=2.5V
V
OUT
=2.0V
V
OUT
=1.8V
Dropout Voltage vs Load Current
Dropout Voltage (mV)
Load Current (mA)
V
OUT
V
OUT
=3.0V
200mV/DIV
I
OUT
I
OUT
=0.1mA
I
OUT
=250mA
Time (0.5mS/DIV)
C
OUT
=1
F
Load Transient Response
V
OUT
V
OUT
=3.0V
I
OUT
I
OUT
=0.1mA
I
OUT
=250mA
Time (0.25mS/DIV)
C
OUT
=10
F
Load Transient Response
50mV/DIV
V
IN
V
IN
=4.0V
V
OUT
V
OUT
=3.0V
Time (1mS/DIV)
V
IN
=6V
Line Transient Response
C
OUT
=1
F
I
L
=1mA
20mV/DIV
Output Current (
mA)
Input voltage (V)
3
4
5
6
7
8
9
10
11
12
0
5 0
100
150
200
250
300
350
400
450
500
550
600
2.7V
2.5V
3.0V
2.0V
1.8V
Recommended Max. Output Current vs Input Voltage
AIC1740
5
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BLOCK DIAGRAM
1.235V
Reference
GND
VOUT
VIN
ERROR
AMP
+
-
THERMAL
SHUTDOWN
-
+
CURRENT
LIMITING
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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 4.7
F (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 5
or less if Aluminum electrolytic type is used.
Many Aluminum electrolytics have electrolytes that
freeze at about -30
C, so solid tantalums are
recommended for operation below -25
C. The
value of this capacitor may be increased without
limit.
A 0.1
F 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).
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