AIC1084
5A Low Dropout Positive Adjustable Regulator
Analog Integrations Corporation 4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC
www.analog.com.tw
DS-1084-03 Sep 21, 01
TEL: 886-3-5772500 FAX: 886-3-5772510
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FEATURES
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Dropout Voltage 1.3V at 5A
Output Current.
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Fast Transient Response.
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Extremely Tight Line and Load Regulation.
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Current Limiting and Thermal Protection.
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Adjustable Output Voltage or Fixed 1.5V, 1.8V,
3.3V.
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Standard 3-Pin Power Packa
ges.
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APPLICATIONS
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Mother Board I/O Power Supplies.
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Microprocessor Power Supplies.
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High Current Regulator.
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Post Regulator for Switching Supply.
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DESCRIPTION
The AIC1084 is a low dropout three terminal
regulator with 5A output current capability. The
output voltage is adjustable with the use of a
resistor divider or fixed 3.3V. Dropout voltage is
guaranteed to be at maximum of 1.4V with the
maximum output current. Its low dropout voltage
and fast transient response make it ideal for low
voltage microprocessor applications. Current limit
and thermal protection provide protection against
any overload condition that would create excessive
junction temperatures.
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TYPICAL APPLICATION CIRCUIT
C2
10
F
V
OUT
3.3V
V
IN
5V
+
+
V
REF
RF2
205
1%
ADJ
AIC1084
C1
10
F
2
3
1
RF1
125
1%
V
R E F
=V
OUT
- V
ADJ
=1.25V (typ.)
V
OUT
=V
REF
x (1+RF2/RF1)+ I
ADJ
x RF2
I
ADJ
=55
A (typ.)
(1) C1 needed if device is far away from filter
capacitors.
(2) C2 required for stability.
Adjustable Voltage Regulator
C2
10
F
V
OUT
3.3V
V
IN
5V
+
+
GND
C1
10
F
AIC1084-33
2
1
3
Fixed Voltage Regulator
AIC1084
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ORDERING INFORMATION
ORDER NUMBER
PIN CONFIGURATION
PACKAGING TYPE
E: TO-252
M: TO-263
T: TO-220
MA: TO-263AA
FRONT VIEW
1: ADJ (GND)
2: VOUT (TAB)
3: VIN
AIC1084CM
(TO-263)
2
3
1
FRONT VIEW
1: ADJ (GND)
2: VOUT (TAB)
3: VIN
AIC1084CE
(TO-252)
2
3
1
FRONT VIEW
1: ADJ (GND)
2: VOUT (TAB)
3: VIN
AIC1084CT
(TO-220)
1 2
3
AIC1084-XXCX
OUTPUT VOLTAGE
DEFAULT: ADJ.
15: 1.5V
18: 1.8V
33: 3.3V
FRONT VIEW
1: ADJ (GND)
2: VOUT (TAB)
3: VIN
AIC1084CMA
(TO-263AA)
2
3
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ABSOLUTE MAXIMUM RATINGS
VIN pin to ADJ/GND pin ......................... ... .................. ... ... .......................... ........... 7V
Operating Junction Temperature Range ..................... ... ... ... ... ...................... 0
C~ 125
C
Storage Temperature Range
.................................. ... ... .... ... ................. - 65
C ~ 150
C
Thermal Resistance Junction to Case TO-252
... ... ... ... ... ... ... ... ... ... ... ... ... 15
C/W
TO-263, TO263AA, TO-220........ ... ... .... 6
C /W
Thermal Resistance Junction to Ambient TO-252
... ... ... ... ... ... ... ... ... ... ..... 100
C/W
(Assume no ambient airflow, no heatsink) TO-263
... ........ ... ........ ... ... ... ... ... 60
C /W
TO-263AA
... ..... ... ..... ... ........ ... ... 60
C /W
TO-220
... ....... ... ....... ... ... ... ... ... .. 50
C /W
Lead Temperature (Soldering) 10 sec. ........................ ... ... ..... ............... ... ..... .......260
C
AIC1084
3
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TEST CIRCUIT
Refer to TYPICAL APPLICATION CIRCUIT.
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ELECTRICAL CHARACTERISTICS
(V
IN
=5V, T
J
=25
C, I
O
=10mA, Unless otherwise
specified)
PARAMETER
TEST CONDITIONS
MIN.
TYP.
MAX.
UNIT
Reference Voltage
AIC1084 (ADJ)
T
J
=25
C
1.238
1.25
1.262
V
Output Voltage
AIC1084-15 V
IN
=5V
AIC1084-18 V
IN
=5V
AIC1084-33 V
IN
=5V
1.48
1.78
3.26
1.50
1.80
3.30
1.52
1.82
3.34
V
Line Regulation
ADJ : 2.65V
V
IN
7V
V
OUT
=1.25V
Fix : V
OUT
+1.4V
V
IN
7V
T
J
=25
C
0.015
0.2
%
Load Regulation
10mA < I
O
< 5A
T
J
=25
C
0.6
%
Dropout Voltage
V
OUT
,
V
REF
=1%
10mA
I
O
5A
0
C
T
J
125
C
1.3
1.4
V
Current Limit
0
C
T
J
125
C
5
6
A
Adjusted Pin Current
2.65V
V
IN
7V
55
120
A
Adjusted Pin Current Change
(
I
ADJ
)
2.65V
V
IN
7V
0
C
T
J
125
C
0.2
5
A
Temperature Stability
I
O
=0.5A
0
C
T
J
125
C
0.5
%
Minimum Load Current
0
C
T
J
125
C
5
10
mA
RMS Output Noise (% of V
OUT
)
10Hz
f
10KHz
0.003
%
Ripple Rejection Ratio
120Hz input ripple
C
OUT
=25
F
(V
IN
-V
OUT
)=3V
60
72
dB
AIC1084
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BLOCK DIAGRAM
VIN
55
A
ADJ
V
REF
1.25V
-
+
GM
+
Thermal
Limit
Current Amp.
VOUT
GND
For fixed voltage
device
Current
Limit
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PIN DESCRIPTIONS
ADJ PIN
-
Providing V
REF
=1.25V (typ.) for adjustable V
OUT
. V
REF
=V
OUT
-V
ADJ
and I
ADJ
=55
A (typ.)
GND PIN- Power ground.
VOUT PIN -
Adjustable output voltage.
VIN PIN
-
Power Input.
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TYPICAL PERFORMANCE CHARACTERISTICS
Fig. 1 Load Transient Response
Time (
S)
Output Voltage
(V, AC)
Load Current
0
20
40
60
80
100
0.1A
2.5A
-0.4
-0.2
0
0.2
0.4
V
IN
=5.0V
C
IN
=1
F(Tantalum)
C
OUT
=10
F(Tantalum)
V
OUT
=3.3V
Fig. 2 Line Transient Response
Time (
S)
Output Voltage
(mV, AC)
Input Voltage (V)
0
40
80
120
160
200
6.0
7.0
-100
-50
0
50
C
IN
=1
F (Tantalum)
C
OUT
=10
F (Tantalum)
V
OUT
=3.3V
AIC1084
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TYPICAL PERFORMANCE CHARACTERISTICS
(Continued)
Fig. 3 Dropout Voltage (V
OUT
=3.3V)
Output Current (A)
Minimum differential Voltage (V)
0
1
2
3
4
5
1.05
1.10
1.15
1.20
1.25
1.30
1.35
Fig. 4 Minimum Operating Current
Differential Voltage (V)
Minimum Operating Current (mA)
0
1
2
3
4
5
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
Fig. 5 Minimum Operating Current
Minimum
Operating Current (
mA)
Differential Voltage (V)
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
8
Fig. 6 AIC1084 (ADJ.) Short Circuit Current
Short
Circuit
Current (A)
V
IN
-V
OUT
(V)
10
1
10
2
10
3
10
4
10
5
10
6
10
7
-80
-70
-60
-50
-40
-30
-20
Fig. 7 AIC1084 (ADJ.) Ripple Rejection
C
OUT
=3.3
F
Ripple Rejection Ratio (dB)
Frequency (Hz)
C
OUT
=10
F
C
OUT
=25
F
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