AIC1085
3A Low Dropout Positive Regulator
FEATURES
Dropout Voltage 1.3V at 3A Output Current.
Fast Transient Response.
Extremely Tight Line and Load Regulation.
Current Limiting and Thermal Protection.
Adjustable Output Voltage or Fixed 1.5V, 1.8V,
2.5V and 3.3V.
Standard 3-Pin Power Packages.
DESCRIPTION
The AIC1085 is a low dropout three terminal
regulator with 3A output current capability. The
output voltage is adjustable with the use of a
resistor divider or fixed 1.5V, 1.8V, 2.5V and 3.3V.
Dropout voltage is guaranteed to be at a 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 limiting and thermal protection provides
protection against any overload condition that
would create excessive junction temperatures.
APPLICATIONS
Mother Board I/O Power Supplies.
Microprocessor Power Supplies.
High Current Regulator.
Post Regulator for Switching Supply.
TYPICAL APPLICATION CIRCUIT
V
IN
5V
3
AIC1085
1 ADJ
C1 +
10µF
2
V
REF
V
OUT
3.3V
RF1
125Ω
+
1%
C2
RF2
10µF
205Ω
(Note1)
1%
V
REF
=
V
OUT
−
V
ADJ
=
1.25V (typ.)
RF2
⎞
⎛
V
OUT
=
V
REF
× ⎜
1
+
⎟ +
I
ADJ
×
RF2
RF1
⎠
⎝
I
ADJ
=
55
µ
A (typ.)
(1) C1 needed if device is far away from
filter capacitors.
(2) C2 required for stability.
Adjustable Voltage Regulator
V
IN
5V
3
AIC1085-33
1
2
V
OUT
3.3V
C1 +
10µF
GND
+
C2
10µF
(Note1)
Fixed Voltage Regulator
Analog Integrations Corporation
Si-Soft Research Center
3A1, No.1, Li-Hsin Rd. I , Science Park , Hsinchu 300, Taiwan , R.O.C.
TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
DS-1085G-01 121208
1
AIC1085
ORDERING INFORMATION
AIC1085-XXXXXX
PIN CONFIGURATION
PACKING TYPE
TR: TAPE & REEL
TB: TUBE
PACKAGING TYPE
E: TO-252
M: TO-263
T: TO-220
C: COMMERCIAL
P: LEAD FREE COMMERCIAL
G: GREEN PACKAGE
OUTPUT VOLTAGE
DEFAULT: ADJUSTABLE
15: 1.5V
18: 1.8V
25: 2.5V
33: 3.3V
Example: AIC1085-15CETR
1.5V version in TO-252 Package &
Taping & Reel Packing Type
AIC1085-15PMTR
1.5V version in TO-263 Lead Free
Package & Taping & Reel Packing
Type
TO-252 (CE&PE)
TOP VIEW
1: ADJ (GND)
2: VOUT (TAB)
3: VIN
1
2
3
TO-263 (CM&PM)
TOP VIEW
1: ADJ (GND)
2: VOUT (TAB)
3: VIN
1
2
3
TO-220 (CT&PT)
FRONT VIEW
1: ADJ (GND)
2: VOUT (TAB)
3: VIN
1 2 3
ABSOLUTE MAXIMUM RATINGS
VIN pin to ADJ/ GND pin
Operating Temperature Range
Storage Temperature Range
Maximum Junction Temperature
Lead Temperature (Soldering, 10 sec)
Thermal Resistance Junction to Case
TO-252
TO-263, TO-220
Thermal Resistance Junction to Ambient
TO-252
TO-220
(Assume no ambient airflow, no heatsink) TO-263
7V
-40°C to 85°C
-65°C to 150°C
125°C
260°C
12.5°C/W
3°C /W
100°C/W
60°C /W
50°C /W
Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.
2
AIC1085
TEST CIRCUIT
Refer to TYPICAL APPLICATION CIRCUIT.
ELECTRICAL CHARACTERISTICS
(V
IN
=5V, T
J
=25°C, I
O
=10mA, unless otherwise specified) (Note2)
PARAMETER
Reference Voltage (V
OUT
-V
ADJ
)
TEST CONDITIONS
AIC1085 (ADJ)
AIC1085-15, V
IN
=5V
AIC1085-18, V
IN
=5V
AIC1085-25, V
IN
=5V
AIC1085-33, V
IN
=5V
ADJ: 2.65V≤ V
IN
≤7V,
V
OUT
=1.25V
Fix : V
OUT
+1.4V≤ V
IN
≤7V
Load Regulation
Dropout Voltage
Current Limit
GND Current (Fix)
Adjusted Pin Current (I
ADJ
)
Adjusted Pin Current Change
(∆I
ADJ
)
Temperature Stability
Minimum Load Current
RMS Output Noise (% of V
OUT
)
Ripple Rejection Ratio
10Hz
≤
f
≤
10KHz
120Hz input ripple
C
OUT
=25µF
(V
IN
-V
OUT
)=3V
Note 3
60
2.65V
≤
V
IN
≤
7V
2.65V
≤
V
IN
≤
7V
2.65V
≤
V
IN
≤
7V
I
O
=0.5A
10mA < I
O
< 3A
∆V
OUT
,
∆V
REF
=1%
10mA
≤
I
O
≤3A
3
1.3
4
11.5
55
0.2
0.5
5
0.003
72
10
14
120
5
0.6
1.4
%
V
A
mA
µA
µA
%
mA
%
dB
°C
MIN.
1.238
1.48
1.78
2.47
3.26
TYP.
1.25
1.50
1.80
2.50
3.30
0.015
MAX.
1.262
1.52
1.82
2.53
3.34
0.2
UNIT
V
Output Voltage
V
Line Regulation
%
Thermal Shutdown Temperature
165
Note 1:
To avoid output oscillation, aluminum electrolytic output capacitor is recommended and ceramic
capacitor is not suggested.
Note 2:
Specifications are production tested at T
A
=25°C. Specifications over the -40°C to 85°C operating
temperature range are assured by design, characterization and correlation with Statistical Quality
Controls (SQC).
Note 3:
Guarantee by design.
3
AIC1085
TYPICAL PERFORMANCE CHARACTERISTICS
0.1
Output Voltage
(V, AC)
Output Voltage
(mV, AC)
0.05
50
0
0
-0.05
-0.1
Input Voltage (V)
Load Current
V
IN
=5V
C
IN
=1µF
C
OUT
=10µF (Tantalum)
V
OUT
=3.3V
--50
--100
C
IN
=1V (Tantalum)
C
OUT
=10µF (Tantalum)
V
OUT
=3.3V
1.5A
7.0
0.1A
6.0
0
40
80
120
160
200
0
10
20
30
40
50
Time (µS)
Fig. 1 Load Transient Response
Time (µS)
Fig. 2 Line Transient Response
1.22
1.20
1.18
1.16
1.14
1.12
1.10
1.08
1.06
0.0
0.5
1.0
1.5
2.0
2.5
3.0
5
Minimum Operating Current (mA)
Minimum Differential Voltage (V)
4
3
2
1
0
Output Current (A)
1
2
3
4
5
6
7
8
9
Fig. 3 Dropout Voltage (V
OUT
=3.3V)
Differential Voltage (V)
Fig. 4 Minimum Operating Current
-20
Ripple Rejection Ratio (dB)
-30
-40
-50
-60
-70
-80
1
10
2
10
3
10
4
10
C
OUT
=3.3µF
C
OUT
=10µF
C
OUT
=25µF
Frequency (Hz)
5
10
6
10
7
10
Fig. 5
AIC1085 (ADJ.) Ripple Rejection
4
AIC1085
BLOCK DIAGRAM
VIN
V
REF
+
1.25V
+
GM
Current Amp.
-
Thermal
Limit
55µA
Current
Limit
VOUT
For fixed voltage
device
ADJ
GND
PIN DESCRIPTIONS
ADJ PIN
-
Providing V
REF
=1.25V (typ.) for adjustable V
OUT
. V
REF
=V
OUT
-V
ADJ
and I
ADJ
=55µA (typ.)
(GND PIN - Power Ground.)
VOUT PIN -
VIN PIN
-
Adjustable output voltage.
Power Input.
5
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