December 2011 Doc ID 7194 Rev 24 1/24
24
LD1117AXX12, LD1117AXX18,
LD1117AXX33, LD1117AXX
Low drop fixed and adjustable positive voltage regulators
Features
■Low dropout voltage:
– 1.15 V typ. @ IOUT = 1 A, 25 °C
■Very low quiescent current:
– 5 mA typ. @ 25 °C
■Output current up to 1 A
■Fixed output voltage of:
– 1.2 V, 1.8 V, 2.5 V, 3.3 V
■Adjustable version availability (VREF = 1.25 V)
■Internal current and thermal limit
■Only 10 µF for stability
■Available in ± 2% (at 25 °C) and 4% in full
temperature range
■High supply voltage rejection:
– 80 dB typ. (at 25 °C)
■Temperature range: 0 °C to 125 °C
Description
The LD1117Axx is a low drop voltage regulator
able to provide up to 1 A of output current,
available also in adjustable versions (VREF =
1.25 V). In fixed versions, the following output
voltages are offered: 1.2 V, 1.8 V, 2.5 V and 3.3 V.
The device is supplied in: SOT-223, DPAK and
TO-220. Surface mounted packages optimize the
thermal characteristics while offering a relevant
space saving advantage. High efficiency is
assured by an NPN pass transistor. Only a very
common 10 µF minimum capacitor is needed for
stability. Chip trimming allows the regulator to
reach a very tight output voltage tolerance, within
± 2% at 25 °C.
SOT-223
TO-220
DPAK
Table 1. Device summary
Order codes
Output voltage
SOT-223 DPAK TO-220
LD1117AS12TR LD1117ADT12TR 1.2 V
LD1117AS18TR LD1117ADT18TR 1.8 V
LD1117AS33TR LD1117ADT33TR LD1117AV33 3.3 V
LD1117ASTR LD1117ADT-TR Adjustable from 1.25 V
www.st.com
Contents LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
2/24 Doc ID 7194 Rev 24
Contents
1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 Schematic application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6 Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7 LD1117A adjustable: application note . . . . . . . . . . . . . . . . . . . . . . . . . 14
8 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX Diagram
Doc ID 7194 Rev 24 3/24
1 Diagram
Figure 1. Block diagram
Pin configuration LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
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2 Pin configuration
Note: The TAB is connected to the VOUT
.
Figure 2. Pin connections (top view)
DPAK
SOT-223 TO-220
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX Maximum ratings
Doc ID 7194 Rev 24 5/24
3 Maximum ratings
Note: Absolute maximum ratings are those values beyond which damage to the device may occur.
Functional operation under these condition is not implied. Beyond the above suggested
max. power dissipation, a short-circuit may permanently damage the device.
Table 2. Absolute maximum ratings
Symbol Parameter Value Unit
VIN DC input voltage 15 V
PDPower dissipation 12 W
TSTG Storage temperature range -40 to +150 °C
TOP Operating junction temperature range 0 to +125 °C
Table 3. Thermal data
Symbol Parameter SOT-223 DPAK TO-220 Unit
RthJC Thermal resistance junction-case 15 8 5 °C/W
RthJA Thermal resistance junction-ambient 50 °C/W
Schematic application LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
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4 Schematic application
Figure 3. Application circuit (for other fixed output voltages)
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX Electrical characteristics
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5 Electrical characteristics
Refer to the test circuits, TJ = 0 to 125 °C, CO = 10 µF, CI = 10 µF, R = 120 Ω between OUT-
GND, unless otherwise specified.
Table 4. Electrical characteristics of LD1117A#12
Symbol Parameter Test conditions Min. Typ. Max. Unit
VOOutput voltage VI = 5.3 V, IO = 10 mA, TJ = 25 °C 1.176 1.2 1.224 V
VOOutput voltage IO = 0 to 1 A, VI = 2.75 to 10 V 1.152 1.2 1.248 V
ΔVOLine regulation VI = 2.75 to 8 V, IO = 0 mA 1 6 mV
ΔVOLoad regulation VI = 2.75 V, IO = 0 to 1 A 1 10 mV
ΔVOTemperature stability 0.5 %
ΔVOLong term stability 1000 hrs, TJ = 125 °C 0.3 %
VIOperating input voltage IO = 100 mA 10 V
IdQuiescent current VI ≤ 8 V, IO = 0 mA 5 10 mA
IOOutput current VI - VO = 5 V, TJ = 25 °C 1000 1200 mA
eN Output noise voltage B =10 Hz to 10 kHz, TJ = 25 °C 100 µV
SVR Supply voltage rejection IO = 40 mA, f = 120 Hz
VI - VO = 3 V, Vripple = 1 VPP
60 80 dB
VDDropout voltage
IO = 100 mA 1 1.10
VIO = 500 mA 1.05 1.15
IO = 1 A 1.15 1.30
ΔVO(pwr) Thermal regulation Ta = 25 °C, 30 ms pulse 0.08 0.2 %/W
Electrical characteristics LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
8/24 Doc ID 7194 Rev 24
Refer to the test circuits, TJ = 0 to 125 °C, CO = 10 µF, CI = 10 µF, unless otherwise
specified.
Table 5. Electrical characteristics of LD1117A#18
Symbol Parameter Test conditions Min. Typ. Max. Unit
VOOutput voltage VI = 3.8 V, IO = 10 mA, TJ = 25 °C 1.764 1.8 1.836 V
VOOutput voltage IO = 0 to 1 A, VI = 3.3 to 8 V 1.728 1.872 V
ΔVOLine regulation VI = 3.3 to 8 V, IO = 0 mA 1 6 mV
ΔVOLoad regulation VI = 3.3 V, IO = 0 to 1 A 1 10 mV
ΔVOTemperature stability 0.5 %
ΔVOLong term stability 1000 hrs, TJ = 125 °C 0.3 %
VIOperating input voltage IO = 100 mA 10 V
IdQuiescent current VI ≤ 8 V, IO = 0 mA 5 10 mA
IOOutput current VI - VO = 5 V, TJ = 25 °C 1000 mA
eN Output noise voltage B =10 Hz to 10 kHz, TJ = 25 °C 100 µV
SVR Supply voltage rejection IO = 40 mA, f = 120 Hz
VI - VO = 3 V, Vripple = 1 VPP
60 80 dB
VDDropout voltage
IO = 100 mA 1 1.10
VIO = 500 mA 1.05 1.15
IO = 1 A 1.15 1.30
ΔVO(pwr) Thermal regulation Ta = 25 °C, 30 ms pulse 0.08 0.2 %/W
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX Electrical characteristics
Doc ID 7194 Rev 24 9/24
Refer to the test circuits, TJ = 0 to 125 °C, CO = 10 µF, CI = 10 µF, unless otherwise
specified.
Table 6. Electrical characteristics of LD1117A#33
Symbol Parameter Test conditions Min. Typ. Max. Unit
VOOutput voltage VI = 5.3 V, IO = 10 mA, TJ = 25 °C 3.234 3.3 3.366 V
VOOutput voltage IO = 0 to 1 A, VI = 4.75 to 10 V 3.168 3.432 V
ΔVOLine regulation VI = 4.75 to 8 V, IO = 0 mA 1 6 mV
ΔVOLoad regulation VI = 4.75 V, IO = 0 to 1 A 1 10 mV
ΔVOTemperature stability 0.5 %
ΔVOLong term stability 1000 hrs, TJ = 125 °C 0.3 %
VIOperating input voltage IO = 100 mA 10 V
IdQuiescent current VI ≤ 10 V, IO = 0 mA 5 10 mA
IOOutput current VI - VO = 5 V, TJ = 25 °C 1000 1200 mA
eN Output noise voltage B =10 Hz to 10 kHz, TJ = 25 °C 100 µV
SVR Supply voltage rejection IO = 40 mA, f = 120 Hz
VI - VO = 3 V, Vripple = 1 VPP
60 75 dB
VDDropout voltage
IO = 100 mA 1 1.10
VIO = 500 mA 1.05 1.15
IO = 1 A 1.15 1.30
ΔVO(pwr) Thermal regulation Ta = 25 °C, 30 ms pulse 0.08 0.2 %/W
Electrical characteristics LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
10/24 Doc ID 7194 Rev 24
Refer to the test circuits, TJ = 0 to 125 °C, CO = 10 µF, CI = 10 µF, unless otherwise
specified.
Table 7. Electrical characteristics of LD1117A (Adjustable)
Symbol Parameter Test conditions Min. Typ. Max. Unit
VOReference voltage VI = 5.3 V, IO = 10 mA, TJ = 25 °C 1.225 1.25 1.275 V
VOReference voltage IO = 10 mA to 1 A, VI = 2.75 to 10 V 1.2 1.3 V
ΔVOLine regulation VI = 2.75 to 8 V, IO = 0 mA 1 6 mV
ΔVOLoad regulation VI = 2.75 V, IO = 0 to 1 A 1 10 mV
ΔVOTemperature stability 0.5 %
ΔVOLong term stability 1000 hrs, TJ = 125 °C 0.3 %
VIOperating input voltage IO = 100 mA 10 V
Iadj Adjustment pin current Vin ≤ 10 V 60 120 µA
ΔIadj
Adjustment pin current
change Vin - VO = 1.4 to 10 V, IO = 10 mA to 1 A 1 5 µA
IO(min) Minimum load current Vin = 10 V 2 5 mA
IOOutput current VI - VO = 5 V, TJ = 25 °C 1000 1200 mA
eN Output noise voltage B =10 Hz to 10 kHz, TJ = 25 °C 100 µV
SVR Supply voltage rejection IO = 40 mA, f = 120 Hz
VI - VO = 3 V, Vripple = 1 VPP
60 80 dB
VDDropout voltage
IO = 100 mA 1 1.10
VIO = 500 mA 1.05 1.15
IO = 1 A 1.15 1.30
ΔVO(pwr) Thermal regulation Ta = 25 °C, 30 ms pulse 0.08 0.2 %/W
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX Typical application
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6 Typical application
Figure 4. Negative supply
Figure 5. Active terminator for SCSI-2 bus
Figure 6. Circuit for increasing output voltage
Typical application LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
12/24 Doc ID 7194 Rev 24
Figure 7. Voltage regulator with reference
Figure 8. Battery backed-up regulated supply
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX Typical application
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Figure 9. Post-regulated dual supply
LD1117A adjustable: application note LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
14/24 Doc ID 7194 Rev 24
7 LD1117A adjustable: application note
The LD1117A adjustable has a thermal stabilized 1.25 ± 0.012 V reference voltage between
the OUT and ADJ pins. IADJ is 60 µA typ. (120 µA max.) and ΔIADJ is 1 µA typ. (5 µA max.).
R1 is normally fixed to 120 Ω. From Figure 7 the following is obtained:
VOUT = VREF + R2 (IADJ + IR1) = VREF + R2 (IADJ +VREF /R1) = VREF (1 + R2 / R1) + R2 x
IADJ.
In normal applications the R2 value is in the range of a few kΩ, so the R2 x IADJ product can
not be considered in the VOUT calculation; the above expression then becomes:
VOUT = VREF (1 + R2 / R1).
In order to have a better load regulation it is important to realize a good Kelvin connection of
R1 and R2 resistors. In particular, the R1 connection must be realized very close to the OUT
and ADJ pins, while the R2 ground connection must be placed as near as possible to the
negative load pin. Ripple rejection can be improved by introducing a 10 µF electrolytic
capacitor placed in parallel to the R2 resistor (see Figure 10).
Figure 10. Adjustable output voltage application
Figure 11. Adjustable output voltage application with improved ripple rejection
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX Package mechanical data
Doc ID 7194 Rev 24 15/24
8 Package mechanical data
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK® packages, depending on their level of environmental compliance. ECOPACK
specifications, grade definitions and product status are available at: www.st.com. ECOPACK
is an ST trademark.
Despite some difference in tolerances, the packages are compatible.
Table 8. TO-220 mechanical data
Dim.
Type STD - ST Dual Gauge Type STD - ST Single Gauge
mm. mm.
Min. Typ. Max. Min. Typ. Max.
A 4.40 4.60 4.40 4.60
b 0.61 0.88 0.61 0.88
b1 1.14 1.70 1.14 1.70
c 0.48 0.70 0.48 0.70
D 15.25 15.75 15.25 15.75
D1 1.27
E 10.00 10.40 10.00 10.40
e 2.40 2.70 2.40 2.70
e1 4.95 5.15 4.95 5.15
F 1.23 1.32 0.51 0.60
H1 6.20 6.60 6.20 6.60
J1 2.40 2.72 2.40 2.72
L 13.00 14.00 13.00 14.00
L1 3.50 3.93 3.50 3.93
L20 16.40 16.40
L30 28.90 28.90
∅P 3.75 3.85 3.75 3.85
Q 2.65 2.95 2.65 2.95
Package mechanical data LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
16/24 Doc ID 7194 Rev 24
Note: 1 Maximum resin gate protrusion: 0.5 mm.
2 An accepted resin gate protrusion can be found in each of the two positions shown on the
drawing, or in their symmetrical position with respect to the vertical axis.
Figure 12. Drawing dimension TO-220 (type STD-ST Dual Gauge)
0015988_S
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX Package mechanical data
Doc ID 7194 Rev 24 17/24
Figure 13. Drawing dimension TO-220 (type STD-ST Single Gauge)
8174627_B
Package mechanical data LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
18/24 Doc ID 7194 Rev 24
Figure 14. Drawing dimension tube for TO-220 Dual Gauge (mm.)
Figure 15. Drawing dimension tube for TO-220 Single Gauge (mm.)
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX Package mechanical data
Doc ID 7194 Rev 24 19/24
Dim.
mm. mils.
Min. Typ. Max. Min. Typ. Max.
A1.870.9
A1 0.02 0.1 0.83.9
B 0.6 0.7 0.8523.6 27.6 33.5
B1 2.933.15 114.2 118.1 124.0
c 0.24 0.26 0.359.4 10.2 13.8
D6.36.5 6.7 248.0 255.9263.8
e2.390.6
e1 4.6 181.1
E3.33.5 3.7 129.9137.8145.7
H6.777.3263.8275.7 287.5
V 10° 10°
SOT-223 mechanical data
0046067/H
Package mechanical data LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
20/24 Doc ID 7194 Rev 24
Dim.
mm. inch.
Min. Typ. Max. Min. Typ. Max.
A 2.2 2.4 0.086 0.094
A1 0.91.1 0.035 0.043
A2 0.030.230.001 0.009
B 0.64 0.90.025 0.035
b4 5.2 5.4 0.204 0.212
C 0.45 0.6 0.017 0.023
C2 0.480.6 0.0190.023
D 6 6.2 0.236 0.244
D1 5.1 0.200
E 6.4 6.6 0.252 0.260
E1 4.7 0.185
e2.280.090
e1 4.4 4.6 0.1730.181
H9.35 10.1 0.3680.397
L 1 0.039
(L1) 2.80.110
L2 0.80.031
L4 0.6 1 0.0230.039
R 0.2 0.008
V2 0° 8°0° 8°
DPAK mechanical data
0068772-F
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX Package mechanical data
Doc ID 7194 Rev 24 21/24
Dim.
mm. inch.
Min. Typ. Max. Min. Typ. Max.
A330 12.992
C 12.813.0 13.2 0.504 0.512 0.519
D 20.2 0.795
N60 2.362
T 14.4 0.567
Ao 6.736.83 6.93 0.265 0.2690.273
Bo 7.32 7.42 7.52 0.288 0.292 0.296
Ko 1.782 0.070 0.078
Po 3.94.0 4.1 0.1530.157 0.161
P7.98.0 8.1 0.311 0.315 0.319
Tape & reel SOT223 mechanical data
Package mechanical data LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
22/24 Doc ID 7194 Rev 24
Dim.
mm. inch.
Min. Typ. Max. Min. Typ. Max.
A330 12.992
C12.813.0 13.2 0.504 0.512 0.519
D 20.2 0.795
N60 2.362
T22.40.882
Ao 6.806.90 7.00 0.2680.272 0.2.76
Bo 10.40 10.50 10.60 0.4090.4130.417
Ko 2.55 2.65 2.75 0.100 0.104 0.105
Po 3.94.0 4.1 0.1530.157 0.161
P7.98.0 8.1 0.311 0.315 0.319
Tape & reel DPAK-PPAK mechanical data
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX Revision history
Doc ID 7194 Rev 24 23/24
9 Revision history
Table 9. Document revision history
Date Revision Changes
29-Sep-2004 11 Add new part number.
12-Oct-2004 12 Mistake VO max. - Table 4.
21-Apr-2005 13 Add new package - D²PAK/A.
05-Jul-2005 14 The DPAK mechanical data updated.
10-Feb-2006 15 Add new package - D²PAK/A (B type).
20-Dec-2006 16 Change value VIN on Ta b le 2 .
19-Jan-2007 17 D²PAK/A mechanical data updated and add footprint data.
28-May-2007 18 Add IADJ and ΔIADJ values on Ta b l e 7 .
07-Jun-2007 19 Add IO(min) value on Ta b l e 7 .
15-Apr-2008 20 Modified: Table 10.
28-Jul-2009 21 Modified: Table 10.
05-Jul-2010 22 Added: Table 8 on page 15, Figure 12 on page 16, Figure 13 on page 17,
Figure 14 and Figure 15 on page 18.
16-Nov-2010 23 Modified: Table 1 on page 1, RthJC value for TO-220 Table 3 on page 5.
16-Dec-2011 24 Modified: VO parameter output voltage ==> Reference voltage Tab le 7 o n
page 10.
LD1117AXX12, LD1117AXX18, LD1117AXX33, LD1117AXX
24/24 Doc ID 7194 Rev 24
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