Data Sheet No. PD94137 revA
IRU1117-18(PbF)
800mA LOW DROPOUT POSITIVE
FIXED 1.8V REGULATOR
DESCRIPTION
The IRU1117-18 is a low dropout three-terminal fixed out-
put regulator with minimum of 800mA output current ca-
pability. This product is specifically designed to provide
well regulated supply for low voltage IC applications as
well as generating clock supply for PC applications. The
IRU1117-18 is guaranteed to have <1.2V dropout at full
load current making it ideal to provide well regulated with
3.8V input supply. The IRU1117-18 is specifically de-
signed to be stable with low cost aluminum capacitors
while maintaining stability with low ESR tantalum caps.
FEATURES
Guaranteed < 1.2V Dropout at 800mA Load
Current
Fast Transient Response
1% Voltage Reference Initial Accuracy
Built-In Thermal Shutdown
Available in SOT-223, D-Pak, Ultra Thin-Pak
TM
and 8-Pin SOIC Surface-Mount Packages
APPLICATIONS
Low Voltage IC Supply Applications
PC Clock Supply Voltage
TYPICAL APPLICATION
3.3V
C1
10uF
V
IN
3
2
1
C2
10uF
IRU1117-18
V
OUT
1.8V / 800mA
Gnd
Figure 1 - Typical set-up of the IRU1117-18 in a 3.3V to 1.8V regulator application.
PACKAGE ORDER INFORMATION
Basic Part (Non-Lead Free)
T
J
(°C)
0 To 125
2-PIN PLASTIC
TO-252 (D-Pak)
IRU1117-18CD
2-PIN PLASTIC
8-PIN PLASTIC
TM
Ultra Thin-Pak (P)
SOIC (S)
IRU1117-18CP
IRU1117-18CS
3-PIN PLASTIC
SOT-223 (Y)
IRU1117-18CY
Leadfree Part
T
J
(°C)
0 To 125
2-PIN PLASTIC
TO-252 (D-Pak)
Not available
2-PIN PLASTIC
8-PIN PLASTIC
TM
Ultra Thin-Pak (P)
SOIC (S)
Not available
IRU1117-18CSPbF
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3-PIN PLASTIC
SOT-223 (Y)
Not available
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IRU1117-18(PbF)
ABSOLUTE MAXIMUM RATINGS
Input Voltage (V
IN
) ....................................................
Power Dissipation .....................................................
Storage Temperature Range ......................................
Operating Junction Temperature Range .....................
7V
Internally Limited
-65°C To 150°C
0°C To 125°C
PACKAGE INFORMATION
2-PIN PLASTIC TO-252 (D-Pak)
3
2-PIN ULTRA THIN-PAK
TM
(P)
3
8-PIN PLASTIC SOIC (S)
3-PIN PLASTIC SOT-223 (Y)
V
IN
Tab is
V
OUT
V
IN
Tab is
V
OUT
1
Gnd
1
Gnd
V
IN
NC
NC
Gnd
1
2
3
4
8
7
6
5
V
OUT
V
OUT
V
OUT
V
OUT
3
V
IN
V
OUT
Gnd
Tab is
V
OUT
2
1
θ
JA
=70°C/W for 0.5" Sq pad
θ
JA
=70°C/W for 0.5" Sq pad
θ
JA
=55°C/W for 1" Sq pad
θ
JA
=90°C/W for 0.4" Sq pad
ELECTRICAL SPECIFICATIONS
Unless otherwise specified, these specifications apply over C
IN
=1µF, V
IN
=5V, C
OUT
=10µF, and T
J
=0 to 125 C.
Typical values refer to T
J
=25 C.
PARAMETER
Output Voltage
Line Regulation
Load Regulation (Note 1)
Dropout Voltage (Note 2)
Current Limit
Thermal Regulation
Ripple Rejection
Temperature Stability
Long Term Stability
RMS Output Noise
SYM
V
O
TEST CONDITION
Io=10mA, T
J
=25 C
Io=10mA
Io=10mA, 4.75V<V
IN
<7V
10mA<Io<800mA
Io=1A
Io=800mA
∆Vo=100mV
30ms Pulse, Io=800mA
f=120Hz, Co=25µF Tantalum,
Io=0.5A
Io=10mA
T
J
=125 C, 1000Hrs
T
J
=25 C, 10Hz<f<10KHz
MIN
1.782
1.764
TYP
1.800
1.800
MAX UNITS
1.818
V
1.896
7
mV
17
mV
1.3
V
1.2
A
%/W
dB
%
%
%V
O
1.2
1.1
1.1
0.01
70
0.5
0.3
0.003
Note 1:
Low duty cycle pulse testing with Kelvin connections is required in order to maintain accurate data.
Note 2:
Dropout voltage is defined as the minimum differential voltage between V
IN
and V
OUT
required to maintain
regulation at V
OUT
. It is measured when the output voltage drops 1% below its nominal value.
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IRU1117-18(PbF)
PIN DESCRIPTIONS
PIN#
1
2
3
PIN SYMBOL PIN DESCRIPTION
Ground pin. This pin must be connected to ground plane using a low inductance short
Gnd
connection.
V
OUT
V
IN
The output of the regulator. This pin is also connected to the tab of the package. An output
capacitor must be connected to this pin to insure stability of the regulator.
Input pin of the regulator. Typically a large storage capacitor is connected from this pin to
ground to insure that the input voltage does not sag below the minimum dropout voltage
during the load transient response. This pin must always be 1.3V higher than V
OUT
in order
for the device to regulate properly.
BLOCK DIAGRAM
V
IN
3
2 V
OUT
+
1.25V
CURRENT
LIMIT
THERMAL
SHUTDOWN
+
1 Gnd
Figure 2 - Simplified block diagram of the IRU1117-18.
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3
IRU1117-18(PbF)
(D) TO-252 Package
2-Pin
A
C
B
K
L
M
45
D
E
O
J
7
N
Q
R
P
F
H
G
S
R1
SYMBOL
A
B
C
D
E
F
G
H
J
K
L
M
N
O
P
Q
R
R1
S
MIN
6.477
5.004
0.686
7.417
9.703
0.635
2.286
MAX
6.731
5.207
0.838
8.179
10.084
0.889
BSC
C
L
4.521 4.623
∅1.52 ∅1.62
2.184 2.388
0.762 0.864
1.016 1.118
5.969 6.223
1.016 1.118
0.102
0
0.534 0.686
R0.31 TYP
R0.51 TYP
0.428 0.588
NOTE: ALL MEASUREMENTS
ARE IN MILLIMETERS.
4
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IRU1117-18(PbF)
(P) Ultra Thin-Pak
TM
2-Pin
A
A1
K
V
B
H
M
L
P
G
G1
C
C
L
SYMBOL
A
A1
B
C
D
E
G
G1
H
K
L
M
N
P
R
U
V
MAX
MIN
6.17
5.91
5.79
5.54
6.27
6.02
2.03
1.70
0.79
0.63
0.33
0.17
2.41
2.16
4.70
4.45
9.68
9.42
1.27
0.76
0.13
0.02
1.14
0.89
0.25
0.25
1.19
0.94
6
2
3.30
2.92
5.08 NOM
E
U
D
N
R
NOTE: ALL MEASUREMENTS
ARE IN MILLIMETERS.
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