Page 1
LT1129/LT1129-3.3/LT1129-5
IN OUT
LT1129-5
GND
5V OUT
500mA
V
IN
> 5.5V
3.3μF
SOLID TANTALUM
+
SENSE
112935 TA01
V
SHDN
(PIN 4)
< 0.25
> 2.8
NC
OUTPUT
OFF
ON
ON
SHDN
1
2
3
4
5
Micropower Low Dropout
Regulators with Shutdown
FEATURES
n
400mV Dropout Voltage
n
700mA Output Current
n
50μA Quiescent Current
n
No Protection Diodes Needed
n
Adjustable Output from 3.8V to 30V
n
3.3V and 5V Fixed Output Voltages
n
Controlled Quiescent Current in Dropout
n
Shutdown
n
16μA Quiescent Current in Shutdown
n
Stable with 3.3μF Output Capacitor
n
Reverse Battery Protection
n
No Reverse Output Current
n
Thermal Limiting
n
Surface Mount SOT-223 and DD-Pak Packages
APPLICATIONS
n
Low Current Regulator
n
Regulator for Battery-Powered Systems
n
Post Regulator for Switching Supplies
n
5V to 3.3V Logic Regulator
DESCRIPTION
The LT®1129/LT1129-3.3/LT1129-5 are micropower low
dropout regulators with shutdown. The devices are capable
of supplying 700mA of output current with a dropout
voltage of 400mV at maximum output. Designed for use
in battery-powered systems, the low quiescent current,
50μA operating and 16μA in shutdown, make them an ideal
choice. The quiescent current does not rise in dropout as
it does with many other low dropout PNP regulators.
Other features of the LT1129 /LT1129-3.3/LT1129-5 include
the ability to operate with small output capacitors. They
are stable with only 3.3μF on the output while most older
devices require between 10μF and 100μF for stability. Also
the input may be connected to ground or a reverse voltage
without reverse current fl ow from output to input. This
makes the LT1129/LT1129-3.3/LT1129-5 ideal for backup
power situations where the output is held high and the
input is at ground or reversed. Under these conditions,
only 16μA will fl ow from the output pin to ground. The
devices are available in 5-lead TO-220, 5-lead DD-Pak and
3-lead SOT-223 packages.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
5V Supply with Shutdown
Dropout Voltage
0.6
0.5
0.4
0.3
0.2
DROPOUT VOLTAGE (V)
0.1
0
0
0.1 0.2
OUTPUT CURRENT (A)
0.4 0.6 0.7
0.3 0.5
112935 TA02
112935ff
1
Page 2
LT1129/LT1129-3.3/LT1129-5
ABSOLUTE MAXIMUM RATINGS
Input Voltage ...................................................... ± 30V*
Output Pin Reverse Current ................................. 10mA
Sense Pin Current ................................................ 10mA
Adjust Pin Current ................................................ 10mA
Sense Pin, Adjust Pin Reverse Voltage ............... –0.6V
Shutdown Pin Input Voltage (Note 2) ......... 6.5V, – 0.6V
Shutdown Pin Input Current (Note 2) .................. 20mA
Output Short-Circuit Duration .......................... Indefi nite
PIN CONFIGURATION
TOP VIEW
1
GND
2
GND
3
GND
4
GND
5
GND
6
GND
7
OUT
8
SENSE
9
GND
10
GND
F PACKAGE
20-LEAD PLASTIC TSSOP
NOTE: ALL GROUND PINS ARE INTERNALLY CONNECTED
= 40°C/W
θ
JA
GND
20
GND
19
GND
18
GND
17
GND
16
GND
15
IN
14
SHDN
13
GND
12
GND
11
TAB
IS
GND
*PIN 2 = SENSE FOR LT1129-3.3/LT1129-5
(Note 1)
Storage Temperature Range .................. – 65°C to 150°C
Operating Junction Temperature Range (Note 3)
LT1129C-X .......................................... 0°C to 125°C
LT1129C-X Extended Temperature Range
(Note 12) ....................................... –40°C to 125°C
LT1129I-X(Note 12) ......................... –40°C to 125°C
LT1129MP-X(Note 12) .....................–55°C to 125°C
Lead Temperature (Soldering, 10 sec) ..................300°C
* For applications requiring input voltage ratings greater than 30V, contact the factory.
FRONT VIEW
5
4
3
2
1
Q PACKAGE
5-LEAD PLASTIC DD
= ADJ FOR LT1129
= 30°C/W
θ
JA
V
IN
SHDN
GND
SENSE/ADJ*
OUTPUT
OUTPUT
SENSE/
*PIN 2 = SENSE FOR LT1129-3.3/LT1129-5
1
2
ADJ*
3
GND
NC
4
S8 PACKAGE
8-LEAD PLASTIC SO
= ADJ FOR LT1129
θ
JA
TOP VIEW
8
7
6
5
= 60°C/W
V
IN
GND
GND
SHDN
OBSOLETE PACKAGE
FRONT VIEW
TAB
IS
GND
ST PACKAGE
3-LEAD PLASTIC SOT-223
θJA = 50°C/W
3
2
1
OUTPUT
GND
V
IN
TAB
IS
GND
*PIN 2 = SENSE FOR LT1129-3.3/LT1129-5 = ADJ FOR LT1129
FRONT VIEW
5
4
3
2
1
T PACKAGE
5-LEAD PLASTIC TO-220
= 50°C/W
θ
JA
V
IN
SHDN
GND
SENSE/ADJ*
OUTPUT
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT1129CS8#PBF LT1129CS8#TRPBF 1129 8-Lead Plastic SO 0°C to 125°C
LT1129IS8#PBF LT1129IS8#TRPBF 1129I 8-Lead Plastic SO –40°C to 125°C
LT1129CS8-3.3#PBF LT1129CS8-3.3#TRPBF 11293 8-Lead Plastic SO 0°C to 125°C
LT1129IS8-3.3#PBF LT1129IS8-3.3#TRPBF 1129I3 8-Lead Plastic SO –40°C to 125°C
LT1129CS8-5#PBF LT1129CS8-5#TRPBF 11295 8-Lead Plastic SO 0°C to 125°C
112935ff
2
Page 3
LT1129/LT1129-3.3/LT1129-5
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT1129IS8-5#PBF LT1129IS8-5#TRPBF 1129I5 8-Lead Plastic SO –40°C to 125°C
LT1129CST-3.3#PBF LT1129CST-3.3#TRPBF 11293 3-Lead Plastic SOT-223 0°C to 125°C
LT1129IST-3.3#PBF LT1129IST-3.3#TRPBF 129I3 3-Lead Plastic SOT-223 –40°C to 125°C
LT1129MPST-3.3#PBF LT1129MPST-3.3#TRPBF 129MP3 3-Lead Plastic SOT-223 –55°C to 125°C
LT1129CST-5#PBF LT1129CST-5#TRPBF 11295 3-Lead Plastic SOT-223 0°C to 125°C
LT1129IST-5#PBF LT1129IST-5#TRPBF 129I5 3-Lead Plastic SOT-223 –40°C to 125°C
LT1129CQ#PBF LT1129CQ#TRPBF LT1129CQ 5-Lead Plastic DD-PAK 0°C to 125°C
LT1129IQ#PBF LT1129IQ#TRPBF LT1129IQ 5-Lead Plastic DD-PAK –40°C to 125°C
LT1129CQ-3.3#PBF LT1129CQ-3.3#TRPBF LT1129CQ-3.3 5-Lead Plastic DD-PAK 0°C to 125°C
LT1129IQ-3.3#PBF LT1129IQ-3.3#TRPBF LT1129IQ-3.3 5-Lead Plastic DD-PAK –40°C to 125°C
LT1129CQ-5#PBF LT1129CQ-5#TRPBF LT1129CQ-5 5-Lead Plastic DD-PAK 0°C to 125°C
LT1129IQ-5#PBF LT1129IQ-5#TRPBF LT1129IQ-5 5-Lead Plastic DD-PAK –40°C to 125°C
LT1129CT#PBF LT1129CT#TRPBF LT1129CT 5-Lead Plastic TO-220 0°C to 125°C
LT1129IT#PBF LT1129IT#TRPBF LT1129IT 5-Lead Plastic TO-220 –40°C to 125°C
LT1129CT-3.3#PBF LT1129CT-3.3#TRPBF LT1129CT-3.3 5-Lead Plastic TO-220 0°C to 125°C
LT1129IT-3.3#PBF LT1129IT-3.3#TRPBF LT1129IT-3.3 5-Lead Plastic TO-220 –40°C to 125°C
LT1129CT-5#PBF LT1129CT-5#TRPBF LT1129CT-5 5-Lead Plastic TO-220 0°C to 125°C
LT1129IT-5#PBF LT1129IT-5#TRPBF LT1129IT-5 5-Lead Plastic TO-220 –40°C to 125°C
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT1129CS8 LT1129CS8#TR 1129 8-Lead Plastic SO 0°C to 125°C
LT1129IS8 LT1129IS8#TR 1129I 8-Lead Plastic SO –40°C to 125°C
LT1129CS8-3.3 LT1129CS8-3.3#TR 11293 8-Lead Plastic SO 0°C to 125°C
LT1129IS8-3.3 LT1129IS8-3.3#TR 1129I3 8-Lead Plastic SO –40°C to 125°C
LT1129CS8-5 LT1129CS8-5#TR 11295 8-Lead Plastic SO 0°C to 125°C
LT1129IS8-5 LT1129IS8-5#TR 1129I5 8-Lead Plastic SO –40°C to 125°C
LT1129CST-3.3 LT1129CST-3.3#TR 11293 3-Lead Plastic SOT-223 0°C to 125°C
LT1129IST-3.3 LT1129IST-3.3#TR 129I3 3-Lead Plastic SOT-223 –40°C to 125°C
LT1129MPST-3.3 LT1129MPST-3.3#TR 129MP3 3-Lead Plastic SOT-223 –55°C to 125°C
LT1129CST-5 LT1129CST-5#TR 11295 3-Lead Plastic SOT-223 0°C to 125°C
LT1129IST-5 LT1129IST-5#TR 129I5 3-Lead Plastic SOT-223 –40°C to 125°C
LT1129CQ LT1129CQ#TR LT1129CQ 5-Lead Plastic DD-PAK 0°C to 125°C
LT1129IQ LT1129IQ#TR LT1129IQ 5-Lead Plastic DD-PAK –40°C to 125°C
LT1129CQ-3.3 LT1129CQ-3.3#TR LT1129CQ-3.3 5-Lead Plastic DD-PAK 0°C to 125°C
LT1129IQ-3.3 LT1129IQ-3.3#TR LT1129IQ-3.3 5-Lead Plastic DD-PAK –40°C to 125°C
LT1129CQ-5 LT1129CQ-5#TR LT1129CQ-5 5-Lead Plastic DD-PAK 0°C to 125°C
LT1129IQ-5 LT1129IQ-5#TR LT1129IQ-5 5-Lead Plastic DD-PAK –40°C to 125°C
LT1129CT LT1129CT#TR LT1129CT 5-Lead Plastic TO-220 0°C to 125°C
LT1129IT LT1129IT#TR LT1129IT 5-Lead Plastic TO-220 –40°C to 125°C
LT1129CT-3.3 LT1129CT-3.3#TR LT1129CT-3.3 5-Lead Plastic TO-220 0°C to 125°C
LT1129IT-3.3 LT1129IT-3.3#TR LT1129IT-3.3 5-Lead Plastic TO-220 –40°C to 125°C
112935ff
3
Page 4
LT1129/LT1129-3.3/LT1129-5
ORDER INFORMATION
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT1129CT-5 LT1129CT-5#TR LT1129CT-5 5-Lead Plastic TO-220 0°C to 125°C
LT1129IT-5 LT1129IT-5#TR LT1129IT-5 5-Lead Plastic TO-220 –40°C to 125°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifi cations, go to: http://www.linear.com/tapeandreel/
The l denotes the specifi cations which apply over the full operating
ELECTRICAL CHARACTERISTICS
temperature range, otherwise specifi cations are at TA = 25°C.
SYMBOL CONDITIONS MIN TYP MAX UNITS
Regulated Output Voltage
(Notes 4, 12)
Line Regulation (Note 12)
Load Regulation (Note 12)
Dropout Voltage
(Note 6)
Ground Pin Current
(Note 7)
Adjust Pin Bias Current (Notes 5, 8) T
Shutdown Threshold V
Shutdown Pin Current (Note 9) V
Quiescent Current in Shutdown
(Note 10)
LT1129-3.3 V
= 3.8V, I
IN
4.3V < V
LT1129-5 VIN = 5.5V, I
6V < V
IN
LT1129 (Note 5) VIN = 4.3V, I
4.8V < V
LT1129-3.3 ΔV
= 4.8V to 20V, I
IN
LT1129-5 ΔVIN = 5.5V to 20V, I
LT1129 (Note 5) ΔVIN = 4.3V to 20V, I
LT1129-3.3 ΔI
ΔI
LT1129-5 ΔI
ΔI
LT1129 (Note 5) ΔI
ΔI
I
= 10mA, TJ = 25°C
LOAD
I
= 10mA
LOAD
I
= 100mA, TJ = 25°C
LOAD
I
= 100mA
LOAD
I
= 500mA, TJ = 25°C
LOAD
I
= 500mA
LOAD
= 700mA, TJ = 25°C
I
LOAD
I
= 700mA
LOAD
I
= 0mA
LOAD
= 10mA
I
LOAD
= 100mA
I
LOAD
= 300mA
I
LOAD
= 500mA
I
LOAD
= 700mA
I
LOAD
= 25°C 150 300 nA
J
= Off to On
OUT
V
= On to Off
OUT
= 0V
SHDN
= 6V, V
V
IN
SHDN
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
= 0V
= 1mA, TJ = 25°C
OUT
< 20V, 1mA < I
IN
= 1mA, TJ = 25°C
OUT
< 20V, 1mA < I
= 1mA, TJ = 25°C
OUT
< 20V, 1mA < I
IN
OUT
OUT
OUT
OUT
< 700mA
OUT
< 700mA
< 700mA
OUT
= 1mA
= 1mA
= 1mA
= 1mA to 700mA, TJ = 25°C
= 1mA to 700mA
= 1mA to 700mA, TJ = 25°C
= 1mA to 700mA
= 1mA to 700mA, TJ = 25°C
= 1mA to 700mA
3.250
l
3.200
4.925
l
4.850
3.695
l
3.640
l
l
l
l
l
l
3.300
3.300
5.000
5.000
3.750
3.750
3.350
3.400
5.075
5.150
3.805
3.860
1.5 10 mV
1.5 10 mV
1.5 10 mV
6
15
6
20
6
15
20
30
20
30
20
30
mV
mV
mV
mV
mV
mV
0.13 0.20
l
0.25
0.25 0.35
l
0.45
0.37 0.45
l
0.60
0.45 0.55
l
l
l
l
l
l
l
l
l
0.25
l
l
50 70 μA
310 450 μA
2.0 3.5 mA
10 20 mA
25 45 mA
50 90 mA
1.2
0.75
610 μA
15 25 μA
0.70
2.8 V
112935ff
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
4
Page 5
LT1129/LT1129-3.3/LT1129-5
OUTPUT CURRENT (A)
DROPOUT VOLTAGE (V)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0.2
0.4
0.5
112935 G01
0.1
0.3
0.6
0.7
0
= TEST POINTS
TJ ≤ 125°C
TJ ≤ 25°C
TEMPERATURE (°C)
–50
DROPOUT VOLTAGE (V)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
50
75
112935 G02
–25
25
100
125
A
C
D
E
B
A. I
LOAD
= 700mA
B. I
LOAD
= 500mA
C. I
LOAD
= 300mA
D. I
LOAD
= 100mA
E. I
LOAD
= 10mA
TEMPERATURE (°C)
–50
QUIESCENT CURRENT (μA)
70
60
50
40
30
20
10
0
0
50
75
112935 G03
–25
25
100
125
V
SHDN
= 0V
V
SHDN
= OPEN (HI)
ELECTRICAL CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating
OUT
= 25°C.
A
RIPPLE
= 0.7A, TJ = 25°C
LOAD
= 0V
= 3.3V, VIN = 0V
OUT
= 5V, VIN = 0V
OUT
= 3.8V, VIN = 0V
OUT
= 0.5V
P-P
,
52 64 dB
l
1.0 mA
16
16
16
voltage will be equal to (V
IN
– V
). Dropout voltage is measured
DROPOUT
between the input pin and the output pin. External voltage drops between
the output pin and the sense pin will add to the dropout voltage.
Note 7: Ground pin current is tested with V
= V
IN
(nominal) and a
OUT
current source load. This means that the device is tested while operating in
its dropout region. This is the worst case ground pin current. The ground
pin current will decrease slightly at higher input voltages.
Note 8: Adjust pin bias current fl ows into the adjust pin.
Note 9: Shutdown pin current at V
= 0V fl ows out of the shutdown pin.
SHDN
Note 10: Quiescent current in shutdown is equal to the sum total of the
shutdown pin current (6μA) and the ground pin current (9μA).
Note 11: Reverse output current is tested with the input pin grounded. The
output pin and the sense pin are forced to the rated output voltage. This
current fl ows into the sense pin and out of the ground pin. For the LT1129
(adjustable version) the sense pin is internally tied to the output pin.
Note 12: The LT1129 regulators are tested and specifi ed under pulse load
conditions such that T
T
= 25°C. For C-grade devices, Regulated Output Voltage, Line Regulation
A
≅ TA. The LT1129C regulators are 100% tested at
J
and Load Regulation performance at –40°C and 125°C is assured by
design, characterization and correlation with statistical process controls.
The LT1129I regulators are guaranteed over the full –40°C to 125°C
operating junction temperature range. The LT1129MP regulators are 100%
tested and guaranteed over the –55°C to 125°C temperature range.
25
25
25
μA
μA
μA
temperature range, otherwise specifi cations are at T
SYMBOL CONDITIONS MIN TYP MAX UNITS
– V
Ripple Rejection V
Current Limit V
Input Reverse Leakage Current V
IN
f
RIPPLE
IN
IN
Reverse Output Current (Note 11) LT1129-3.3 V
LT1129-5 V
LT1129 (Note 5) V
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The shutdown pin input voltage rating is required for a low
impedance source. Internal protection devices connected to the shutdown
pin will turn on and clamp the pin to approximately 7V or –0.6V. This
range allows the use of 5V logic devices to drive the pin directly. For high
impedance sources or logic running on supply voltages greater than 5.5V,
the maximum current driven into the shutdown pin must be limited to less
than 20mA.
Note 3: For junction temperatures greater than 110°C, a minimum load
of 1mA is recommended. For T
> 110°C and I
J
may increase by 1%.
Note 4: Operating conditions are limited by maximum junction
temperature. The regulated output voltage specifi cation will not apply
for all possible combinations of input voltage and output current. When
operating at maximum input voltage, the output current range must be
limited. When operating at maximum output current, the input voltage
range must be limited.
Note 5: The LT1129 is tested and specifi ed with the adjust pin connected
to the output pin.
Note 6: Dropout voltage is the minimum input/output voltage required to
maintain regulation at the specifi ed output current. In dropout the output
= 1V (Avg), V
OUT
= 120Hz, I
– V
= 7V, TJ = 25°C 1.2 1.6 A
OUT
= –20V, V
< 1mA, output voltage
OUT
TYPICAL PERFORMANCE CHARACTERISTICS
Guaranteed Dropout Voltage Dropout Voltage Quiescent Current
112935ff
5
Page 6
LT1129/LT1129-3.3/LT1129-5
TEMPERATURE (°C)
–50
ADJUST PIN VOLTAGE (V)
3.400
3.375
3.350
3.325
3.300
3.275
3.250
3.225
3.200
0
50
75
112935 G07
–25
25
100
125
I
LOAD
= 1mA
TEMPERATURE (°C)
–50
ADJUST PIN VOLTAGE (V)
3.850
3.825
3.800
3.775
3.750
3.725
3.700
3.675
3.650
0
50
75
112935 G09
–25
25
100
125
I
LOAD
= 1mA
TEMPERATURE (°C)
–50
OUTPUT VOLTAGE (V)
5.100
5.075
5.050
5.025
5.000
4.975
4.950
4.925
4.900
0
50
75
112935 G08
–25
25
100
125
I
LOAD
= 1mA
TYPICAL PERFORMANCE CHARACTERISTICS
LT1129-3.3
Quiescent Current
250
225
200
175
150
125
100
75
QUIESCENT CURRENT (μA)
50
25
0
0
V
SHDN
2
13579
INPUT VOLTAGE (V)
LT1129-3.3
Output Voltage
= OPEN (HI)
V
SHDN
4
= 0V
6
I
LOAD
R
LOAD
8
= 0
=
∞
112935 G04
250
225
200
175
150
125
100
75
QUIESCENT CURRENT (μA)
50
25
10
0
LT1129-5
Quiescent Current
I
LOAD
R
LOAD
V
= OPEN (HI)
SHDN
V
= 0V
SHDN
2
0
13579
INPUT VOLTAGE (V)
6
4
8
LT1129-5
Output Voltage
= 0
=
∞
112935 G05
250
225
200
175
150
125
100
75
QUIESCENT CURRENT (μA)
50
25
10
LT1129
Quiescent Current
I
LOAD
R
LOAD
V
OUT
V
= OPEN (HI)
SHDN
V
= 0V
SHDN
0
2
0
13579
INPUT VOLTAGE (V)
6
4
LT1129
Adjust Pin Voltage
= 0
= V
8
=
∞
ADJ
112935 G06
10
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
GROUND PIN CURRENT (mA)
0.4
0.2
0
0
6
LT1129-3.3
Ground Pin Current
TJ = 25°C
=
V
OUT
V
SENSE
*FOR V
OUT
2
13579
4
INPUT VOLTAGE (V)
= 3.3V
6
R
I
LOAD
R
I
LOAD
R
I
LOAD
LOAD
= 33Ω
LOAD
= 100mA*
= 66Ω
LOAD
= 50mA*
= 330Ω
= 10mA*
8
112935 G10
LT1129-5
Ground Pin Current
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
GROUND PIN CURRENT (mA)
0.4
0.2
0
10
0
TJ = 25°C
V
= V
OUT
SENSE
*FOR V
OUT
2
13579
4
INPUT VOLTAGE (V)
= 5V
6
I
LOAD
I
I
R
R
LOAD
R
LOAD
= 50Ω
LOAD
= 100mA*
= 100Ω
LOAD
= 50mA*
= 500Ω
LOAD
= 10mA*
8
112935 G11
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
GROUND PIN CURRENT (mA)
0.4
0.2
10
0
0
LT1129
Ground Pin Current
TJ = 25°C
=
V
OUT
V
ADJ
*FOR V
OUT
2
13579
4
INPUT VOLTAGE (V)
= 3.75V
6
I
LOAD
I
R
I
LOAD
R
R
LOAD
LOAD
= 38Ω
LOAD
= 100mA*
= 75Ω
LOAD
= 50mA*
= 375Ω
= 10mA*
8
112935 G12
10
112935ff
Page 7
LT1129/LT1129-3.3/LT1129-5
OUTPUT CURRENT (A)
0
GROUND PIN CURRENT (mA)
70
60
50
40
30
20
10
0
0.2
0.4
0.5
112935 G16
0.1
0.3
0.6
0.7
TJ = 25°C
TJ = 125°C
TJ = –50°C
VIN = 3.3V (LT1129-3.3)
V
IN
= 5V (LT1129-5)
V
IN
= 3.75V (LT1129)
DEVICE IS OPERATING
IN DROPOUT
TEMPERATURE (°C)
–50
SHUTDOWN THRESHOLD (V)
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
50
75
112935 G17
–25
25
100
125
I
LOAD
= 1mA
TEMPERATURE (°C)
–50
SHUTDOWN THRESHOLD (V)
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
50
75
112935 G18
–25
25
100
125
I
LOAD
= 1mA
I
LOAD
= 700mA
TYPICAL PERFORMANCE CHARACTERISTICS
LT1129-3.3
Ground Pin Current
60
TJ = 25°C
= V
V
OUT
50
40
30
20
GROUND PIN CURRENT (mA)
10
0
0
SENSE
*FOR V
2
13579
4
INPUT VOLTAGE (V)
Ground Pin Current
OUT
= 3.3V
6
R
I
LOAD
I
LOAD
I
LOAD
R
R
= 4.7Ω
LOAD
= 700mA*
LOAD
= 500mA*
LOAD
= 300mA*
8
= 6.6Ω
= 11Ω
112935 G13
60
50
40
30
20
GROUND PIN CURRENT (mA)
10
0
10
0
LT1129-5
Ground Pin Current
TJ = 25°C
= V
V
OUT
SENSE
R
= 7.1Ω
LOAD
= 700mA*
I
LOAD
R
= 10Ω
LOAD
= 500mA*
I
LOAD
R
= 16.6Ω
LOAD
= 300mA*
I
LOAD
*FOR V
2
13579
INPUT VOLTAGE (V)
= 5V
OUT
6
4
8
112935 G14
Shutdown Pin Threshold
(On-to-Off)
60
50
40
30
20
GROUND PIN CURRENT (mA)
10
10
0
LT1129
Ground Pin Current
TJ = 25°C
= V
V
OUT
ADJ
R
= 5.3Ω
LOAD
= 700mA*
I
LOAD
R
= 7.5Ω
LOAD
= 500mA*
I
LOAD
R
= 12.6Ω
LOAD
= 300mA*
I
LOAD
*FOR V
2
0
13579
INPUT VOLTAGE (V)
= 3.75V
OUT
6
4
8
Shutdown Pin Threshold
(Off-to-On)
10
112935 G15
Shutdown Pin Current Shutdown Pin Input Current Adjust Pin Bias Current
10
V
9
8
7
6
5
4
3
2
SHUTDOWN PIN CURRENT (μA)
1
0
–50
= 0V
SHDN
–25
50
25
0
TEMPERATURE (°C)
25
20
15
10
5
SHUTDOWN PIN INPUT CURRENT (mA)
0
13
0
2
100
112935 G19
125
SHUTDOWN PIN VOLTAGE (V)
75
4
7
59
8
6
112935 G20
400
V
= V
–25
OUT
0
= 3.75V
25
TEMPERATURE (°C)
ADJ
350
300
250
200
150
100
ADJUST PIN BIAS CURRENT (nA)
50
0
–50
50
75
100
112935 G21
112935ff
125
7
Page 8
LT1129/LT1129-3.3/LT1129-5
TIME (μs)
0
OUTPUT VOLTAGE
DEVIATION (V)
0.10
0.05
0
–0.05
–0.10
400
112935 G29
50
200
300
500
0.6
0.5
LOAD CURRENT
(A)
100
150
250 350 450
VIN = 6V
C
IN
= 3.3μF
C
OUT
= 3.3μF
TIME (ms)
0
OUTPUT VOLTAGE
DEVIATION (V)
0.2
0.1
0
–0.1
–0.2
1.6
112935 G30
0.2
0.8
1.2
2.0
0.7
0.5
0.3
0.1
LOAD CURRENT
(A)
0.4
0.6
1.0 1.4 1.8
VIN = 6V
C
IN
= 3.3μF
C
OUT
= 47μF
TYPICAL PERFORMANCE CHARACTERISTICS
Reverse Output Current Current Limit Current Limit
30
VIN = 0V
= V
V
OUT
25
20
15
10
OUTPUT CURRENT (μA)
5
0
–50
SENSE
= V
V
OUT
SENSE
= V
ADJ
0
–25
TEMPERATURE (°C)
= 3.75V (LT1129)
V
OUT
= 5V (LT1129-5)
= 3.3V (LT1129-3.3)
50
25
75
100
112935 G22
125
1.4
V
= 0V
OUT
1.2
1.0
0.8
0.6
0.4
SHORT-CIRCUIT CURRENT (A)
0.2
0
0
1
3
2
INPUT VOLTAGE (V)
4
5
6
112935 G23
7
Reverse Output Current Ripple Rejection Ripple Rejection
100
TJ = 25°C, VIN = 0V
90
V
= V
OUT
SENSE
(LT1129-3.3/LT1129-5)
80
V
= V
OUT
70
60
50
40
30
OUTPUT CURRENT (μA)
20
10
0
0
ADJ
CURRENT FLOWS
INTO DEVICE
LT1129-3.3
2
13579
OUTPUT VOLTAGE (V)
(LT1129)
4
LT1129
LT1129-5
6
8
10
112935 G25
70
(VIN – V
68
V
IL = 0.7A
66
64
62
60
RIPPLE REJECTION (dB)
58
56
–50
RIPPLE
–25
OUT
= 0.5V
)
AVG
0
TEMPERATURE (°C)
= 1V
P-P
50
25
75
100
112935 G26
125
1.4
1.2
1.0
0.8
0.6
0.4
SHORT-CIRCUIT CURRENT (A)
0.2
0
–50
100
90
80
70
60
50
40
30
RIPPLE REJECTION (dB)
20
10
0
10 1k 10k 1M
VIN = 7V
= 0V
V
OUT
50
25
0
–25
TEMPERATURE (°C)
I
= 500mA
OUT
V
= 6V + 50mV
IN
100 100k
RIPPLE
RMS
FREQUENCY (Hz)
75
C
OUT
TANTALUM
C
= 3.3μF
OUT
SOLID
TANTALUM
100
112935 G24
= 47μF
SOLID
112935 G27
125
–5
8
Load Regulation
0
–10
–15
–20
LOAD REGULATION (mV)
–25
–30
–50
VIN = V
ΔI
LOAD
*V
ADJ
–25
LT1129-3.3
LT1129*
(NOMINAL) + 1V
OUT
= 1mA to 700mA
= V
OUT
0
TEMPERATURE (°C)
25
LT1129-5
50
75
100
112935 G28
125
LT1129-5
Transient Response
LT1129-5
Transient Response
112935ff
Page 9
PIN FUNCTIONS
LT1129/LT1129-3.3/LT1129-5
Input Pin: Power is supplied to the device through the
input pin. The input pin should be bypassed to ground
if the device is more than 6 inches away from the main
input fi lter capacitor. In general, the output impedance of
a battery rises with frequency so it is advisable to include
a bypass capacitor in battery-powered circuits. A bypass
capacitor in the range of 1μF to 10μF is suffi cient. The
LT1129 is designed to withstand reverse voltages on the
input pin with respect to both ground and the output pin.
In the case of a reversed input, which can happen if a
battery is plugged in backwards, the LT1129 will act as if
there is a diode in series with its input. There will be no
reverse current fl ow into the LT1129 and no reverse voltage will appear at the load. The device will protect both
itself and the load.
Output Pin: The output pin supplies power to the load. An
output capacitor is required to prevent oscillations. See
the Applications Information section for recommended
value of output capacitance and information on reverse
output characteristics.
Shutdown Pin (SHDN): This pin is used to put the device
into shutdown. In shutdown the output of the device is
turned off. This pin is active low. The device will be shut
down if the shutdown pin is actively pulled low. The
shutdown pin current with the pin pulled to ground will
be 6μA. The shutdown pin is internally clamped to 7V
and –0.6V (one V
). This allows the shutdown pin to be
BE
driven directly by 5V logic or by open collector logic with
a pull-up resistor. The pull-up resistor is only required
to supply the leakage current of the open collector gate,
normally several microamperes. Pull-up current must be
limited to a maximum of 20mA. A curve of shutdown pin
input current as a function of voltage appears in the Typical
Performance Characteristics. If the shutdown pin is not
used it can be left open circuit. The device will be active,
output on, if the shutdown pin is not connected.
Sense Pin: For fi xed voltage versions of the LT1129
(LT1129-3.3, LT1129-5) the sense pin is the input to the
error amplifi er. Optimum regulation will be obtained at the
point where the sense pin is connected to the output pin.
For most applications the sense pin is connected directly
to the output pin at the regulator. In critical applications
small voltage drops caused by the resistance (R
) of PC
P
traces between the regulator and the load, which would
normally degrade regulation, may be eliminated by connecting the sense pin to the output pin at the load as
shown in Figure 1 (Kelvin Sense Connection). Note that
the voltage drop across the external PC traces will add to
the dropout voltage of the regulator. The sense pin bias
current is 15μA at the nominal regulated output voltage.
This pin is internally clamped to –0.6V (one V
BE
).
Adjust Pin: For the LT1129 (adjustable version) the adjust
pin is the input to the error amplifi er. This pin is internally
clamped to 6V and –0.6V (one V
). This pin has a bias
BE
current of 150nA which fl ows into the pin. See Bias Current curve in the Typical Performance Characteristics. The
adjust pin reference voltage is equal to 3.75V referenced
to ground.
R
IN
1μF
SHDN
Figure 1. Kelvin Sense Connection
OUT
LT1129
SENSE
GND
P
10μF
R
P
LOAD
+
112935 F01
APPLICATIONS INFORMATION
The LT1129 is a micropower low dropout regulator with
shutdown, capable of supplying 700mA of output current
at a dropout voltage of 0.4V. The device operates with very
low quiescent current (50μA). In shutdown the quiescent
current drops to only 16μA. In addition to the low quiescent current the LT1129 incorporates several protection
features which make it ideal for use in battery-powered
systems. The device is protected against reverse input
voltages. In battery backup applications where the output
can be held up by a backup battery when the input is pulled
to ground, the LT1129 acts like it has a diode in series
with its output and prevents reverse current fl ow.
112935ff
9
Page 10
LT1129/LT1129-3.3/LT1129-5
12V
3.75
V
• –6mV
()
= –19mV
()
APPLICATIONS INFORMATION
Adjustable Operation
The adjustable version of the LT1129 has an output voltage
range of 3.75V to 30V. The output voltage is set by the
ratio of two external resistors as shown in Figure 2. The
device servos the output voltage to maintain the voltage
at the adjust pin at 3.75V. The current in R1 is then equal
to 3.75V/R1. The current in R2 is equal to the sum of the
current in R1 and the adjust pin bias current. The adjust
pin bias current, 150nA at 25°C, fl ows through R2 into the
adjust pin. The output voltage can be calculated according
to the formula in Figure 2. The value of R1 should be less
than 400k to minimize errors in the output voltage caused
by the adjust pin bias current. Note that in shutdown the
output is turned off and the divider current will be zero.
Curves of Adjust Pin Voltage vs Temperature and Adjust
Pin Bias Current vs Temperature appear in the Typical
Performance Characteristics. The reference voltage at
the adjust pin has a positive temperature coeffi cient of
approximately 15ppm/°C. The adjust pin bias current has
a negative temperature coeffi cient. These effects are small
and will tend to cancel each other.
The adjustable device is specifi ed with the adjust pin tied
to the output pin. This sets the output voltage to 3.75V.
Specifi cations for output voltages greater than 3.75V will
be proportional to the ratio of the desired output voltage
to 3.75V (V
/ 3.75V). For example: load regulation for an
OUT
output current change of 1mA to 700mA is – 6mV typical at
= 3.75V. At V
V
OUT
= 12V, load regulation would be:
OUT
IN
SHDN
V
= 3.75V 1 + + I
OUT
= 3.75V
V
ADJ
I
= 150nA at 25°C
ADJ
OUTPUT RANGE = 3.75V to 30V
Figure 2. Adjustable Operation
OUT
LT1129
ADJ
GND
R2
()
()
R1
ADJ
R2
R1
• R2
V
OUT
+
112935 F02
Thermal Considerations
The power handling capability of the device will be limited
by the maximum rated junction temperature (125°C). The
power dissipated by the device will be made up of two
components:
1. Output current multiplied by the input/output voltage
differential: I
• (VIN – V
OUT
OUT
), and
2. Ground pin current multiplied by the input voltage:
GND
• VIN.
I
The ground pin current can be found by examining the
Ground Pin Current curves in the Typical Performance
Characteristics. Power dissipation will be equal to the
sum of the two components listed above.
The LT1129 series regulators have internal thermal
limiting designed to protect the device during overload
conditions. For continuous normal load conditions the
maximum junction temperature rating of 125°C must not
be exceeded. It is important to give careful consideration
to all sources of thermal resistance from junction to ambient. Additional heat sources mounted nearby must also be
considered.
For surface mount devices heat sinking is accomplished
by using the heat spreading capabilities of the PC board
and its copper traces. Experiments have shown that the
heat spreading copper layer does not need to be electrically connected to the tab of the device. The PC material
can be very effective at transmitting heat between the pad
area, attached to the tab of the device, and a ground or
power plane layer either inside or on the opposite side of
the board. Although the actual thermal resistance of the
PC material is high, the length/area ratio of the thermal
resistor between layers is small. Copper board stiffeners
and plated through holes can also be used to spread the
heat generated by power devices.
The following tables list thermal resistances for each
package. For the TO-220 package, thermal resistance
is given for junction-to-case only since this package
is usually mounted to a heat sink. Measured values of
thermal resistance for several different board sizes and
copper areas are listed for each package. All measurements were taken in still air on 3/32" FR-4 board with 1-oz
112935ff
10
Page 11
OPERATION
LT1129/LT1129-3.3/LT1129-5
copper. This data can be used as a rough guideline in
estimating thermal resistance. The thermal resistance for
each application will be affected by thermal interactions
with other components as well as board size and shape.
Some experimentation will be necessary to determine the
actual value.
Table 1. Q Package, 5-Lead DD
COPPER AREA
TOPSIDE* BACKSIDE BOARD AREA
2500 sq. mm 2500 sq. mm 2500 sq. mm 25°C/W
1000 sq. mm 2500 sq. mm 2500 sq. mm 27°C/W
125 sq. mm 2500 sq. mm 2500 sq. mm 35°C/W
* Tab of device attached to topside copper
Table 2. ST Package, 3-Lead SOT-223
COPPER AREA
TOPSIDE* BACKSIDE BOARD AREA
2500 sq. mm 2500 sq. mm 2500 sq. mm 45°C/W
1000 sq. mm 2500 sq. mm 2500 sq. mm 45°C/W
225 sq. mm 2500 sq. mm 2500 sq. mm 53°C/W
100 sq. mm 2500 sq. mm 2500 sq. mm 59°C/W
* Tab of device attached to topside copper
Table 3. S8 Package, 8-Lead Plastic SOIC
COPPER AREA
TOPSIDE* BACKSIDE BOARD AREA
2500 sq. mm 2500 sq. mm 2500 sq. mm 55°C/W
1000 sq. mm 2500 sq. mm 2500 sq. mm 55°C/W
225 sq. mm 2500 sq. mm 2500 sq. mm 63°C/W
100 sq. mm 2500 sq. mm 2500 sq. mm 69°C/W
* Device attached to topside copper
T Package, 5-Lead TO-220
Thermal Resistance (Junction-to-Case) = 5°C/W
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
The power dissipated by the device will be equal to:
I
where, I
V
I
OUT MAX
OUT MAX
IN MAX
GND
• (V
IN MAX
= 500mA
= 5.5V
at (I
= 500mA, VIN = 5.5V) = 25mA
OUT
– V
OUT
) + (I
GND
• V
IN MAX
)
so, P = 500mA • (5.5V – 3.3V) + (25mA • 5.5V)
= 1.24W
If we use a DD package, then the thermal resistance will be
in the range of 25°C/W to 35°C/W depending on copper
area. So the junction temperature rise above ambient will
be approximately equal to:
1.24W • 30°C/W = 37.2°C
The maximum junction temperature will then be equal to
the maximum junction temperature rise above ambient
plus the maximum ambient temperature or:
T
= 50°C + 37.2°C = 87.2°C
JMAX
Output Capacitance and Transient Performance
The LT1129 is designed to be stable with a wide range
of output capacitors. The minimum recommended value
is 3.3μF with an ESR of 2Ω or less. The LT1129 is a
micropower device and output transient response will
be a function of output capacitance. See the Transient
Response curves in the Typical Performance Characteristics. Larger values of output capacitance will decrease
the peak deviations and provide improved output transient
response. Bypass capacitors, used to decouple individual
components powered by the LT1129, will increase the
effective value of the output capacitor.
Protection Features
Calculating Junction Temperature
Example: Given an output voltage of 3.3V, an input voltage
range of 4.5V to 5.5V, an output current range of 0mA to
500mA, and a maximum ambient temperature of 50°C,
what will the maximum junction temperature be?
The LT1129 incorporates several protection features
which make it ideal for use in battery-powered circuits.
In addition to the normal protection features associated
with monolithic regulators, such as current limiting and
thermal limiting, the device is protected against reverse
input voltages, and reverse voltages from output to input.
For fi xed voltage devices the output and sense pins are
tied together at the output.
112935ff
11
Page 12
LT1129/LT1129-3.3/LT1129-5
OUTPUT VOLTAGE (V)
0
OUTPUT PIN CURRENT (μA)
100
90
80
70
60
50
40
30
20
10
0
8
112935 F03
2
4
6
10
13579
TJ = 25°C
V
IN
= 0V
V
SENSE
= V
OUT
CURRENT FLOWS
INTO DEVICE
LT1129-3.3
LT1129
LT1129-5
APPLICATIONS INFORMATION
Current limit protection and thermal overload protection
are intended to protect the device against current overload
conditions at the output of the device. For normal operation,
the junction temperature should not exceed 125°C.
The input of the device will withstand reverse voltages
of 30V. Current fl ow into the device will be limited to less
than 1mA (typically less than 100μA) and no negative
voltage will appear at the output. The device will protect
both itself and the load. This provides protection against
batteries that can be plugged in backwards.
For fi xed voltage versions of the device, the sense pin
is internally clamped to one diode drop below ground.
For the adjustable version of the device, the output pin
is internally clamped at one diode drop below ground. If
the output pin of an adjustable device, or the sense pin
of a fi xed voltage device, is pulled below ground, with the
input open or grounded, current must be limited to less
than 5mA.
In circuits where a backup battery is required, several
different input/output conditions can occur. The output
voltage may be held up while the input is either pulled
to ground, pulled to some intermediate voltage, or is left
open circuit. Current fl ow back into the output will vary
depending on the conditions. Many battery-powered
circuits incorporate some form of power management.
The following information will help optimize battery life.
Table 4 summarizes the following information.
The reverse output current will follow the curve in Figure 3
when the input pin is pulled to ground. This current fl ows
through the output pin to ground. The state of the shutdown
pin will have no effect on output current when the input
pin is pulled to ground.
In some applications it may be necessary to leave the
input to the LT1129 unconnected when the output is held
high. This can happen when the LT1129 is powered from
a rectifi ed AC source. If the AC source is removed, then
the input of the LT1129 is effectively left fl oating. The
reverse output current also follows the curve in Figure 3
if the input pin is left open. The state of the shutdown pin
will have no effect on the reverse output current when the
input pin is fl oating.
When the input of the LT1129 is forced to a voltage below
its nominal output voltage and its output is held high, the
reverse output current will still follow the curve shown
in Figure 3. This can happen if the input of the LT1129 is
connected to a discharged (low voltage) battery and the
output is held up by either a backup battery or by a second
regulator circuit.
When the input pin is forced below the output pin or the
output pin is pulled above the input pin, the input current will
typically drop to less than 2μA (see Figure 4). The state of
the shutdown pin will have no effect on the reverse output
current when the output is pulled above the input.
12
Figure 3. Reverse Output Current
5
V
= 3.3V (LT1129-3.3)
OUT
V
= 5V (LT1129-5)
OUT
4
3
2
INPUT CURRENT (μA)
1
0
1
0
Figure 4. Input Current
3
2
INPUT VOLTAGE (V)
4
5
112935 F04
112935ff
Page 13
APPLICATIONS INFORMATION
F20 TSSOP 0204
0.09 – 0.20
(.0035 – .0079)
0° – 8°
0.25
REF
0.50 – 0.75
(.020 – .030)
4.30 – 4.50**
(.169 – .177)
1345678910
111214 13
6.40 – 6.60*
(.252 – .260)
20 19 18 17 16 15
1.10
(.0433)
MAX
0.05 – 0.15
(.002 – .006)
0.65
(.0256)
BSC
6.40
(.252)
BSC
0.19 – 0.30
(.0075 – .0118)
TYP
2
MILLIMETERS
(INCHES)
DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED .152mm (.006") PER SIDE
*
NOTE:
1. CONTROLLING DIMENSION: MILLIMETERS
2. DIMENSIONS ARE IN
3. DRAWING NOT TO SCALE
RECOMMENDED SOLDER PAD LAYOUT
0.45 ±0.05
0.65 BSC
4.50 ±0.10
6.60 ±0.10
1.05 ±0.10
Table 4. Fault Conditions
INPUT PIN SHDN PIN OUTPUT PIN
(Nominal) Open (Hi) Forced to V
< V
OUT
< V
(Nominal) Grounded Forced to V
OUT
Open Open (Hi) Forced to V
Open Grounded Forced to V
(Nominal) Reverse Output Current ≈ 15μA (See Figure 3)
OUT
(Nominal) Reverse Output Current ≈ 15μA (See Figure 3)
OUT
(Nominal) Reverse Output Current ≈ 15μA (See Figure 3)
OUT
(Nominal) Reverse Output Current ≈ 15μA (See Figure 3)
OUT
PACKAGE DESCRIPTION
20-Lead Plastic TSSOP (4.4mm)
LT1129/LT1129-3.3/LT1129-5
Input Current ≈ 1μA (See Figure 4)
Input Current ≈ 1μA (See Figure 4)
F Package
(LTC DWG # 05-08-1650)
OBSOLETE PACKAGE
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
112935ff
13
Page 14
LT1129/LT1129-3.3/LT1129-5
Q(DD5) 0502
.028 – .038
(0.711 – 0.965)
TYP
.143
+.012
–.020
()
3.632
+0.305
–0.508
.067
(1.702)
BSC
.013 – .023
(0.330 – 0.584)
.095 – .115
(2.413 – 2.921)
.004
+.008
–.004
()
0.102
+0.203
–0.102
.050 ± .012
(1.270 ± 0.305)
.059
(1.499)
TYP
.045 – .055
(1.143 – 1.397)
.165 – .180
(4.191 – 4.572)
.330 – .370
(8.382 – 9.398)
.060
(1.524)
TYP
.390 – .415
(9.906 – 10.541)
15° TYP
.420
.350
.565
.090
.042
.067
RECOMMENDED SOLDER PAD LAYOUT
.325
.205
.080
.565
.090
RECOMMENDED SOLDER PAD LAYOUT
FOR THICKER SOLDER PASTE APPLICATIONS
.042
.067
.420
.276
.320
NOTE:
1. DIMENSIONS IN INCH/(MILLIMETER)
2. DRAWING NOT TO SCALE
.300
(7.620)
.075
(1.905)
.183
(4.648)
.060
(1.524)
.060
(1.524)
.256
(6.502)
BOTTOM VIEW OF DD PAK
HATCHED AREA IS SOLDER PLATED
COPPER HEAT SINK
PACKAGE DESCRIPTION
5-Lead Plastic DD Pak
(LTC DWG # 05-08-1461)
Q Package
14
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
112935ff
Page 15
PACKAGE DESCRIPTION
.114 – .124
(2.90 – 3.15)
.248 – .264
(6.30 – 6.71)
.130 – .146
(3.30 – 3.71)
.264 – .287
(6.70 – 7.30)
.0905
(2.30)
BSC
.033 – .041
(0.84 – 1.04)
.181
(4.60)
BSC
.024 – .033
(0.60 – 0.84)
.071
(1.80)
MAX
10°
MAX
.012
(0.31)
MIN
.0008 – .0040
(0.0203 – 0.1016)
10° – 16°
.010 – .014
(0.25 – 0.36)
10° – 16°
RECOMMENDED SOLDER PAD LAYOUT
ST3 (SOT-233) 0502
.129 MAX
.059 MAX
.059 MAX
.181 MAX
.039 MAX
.248 BSC
.090
BSC
.016 – .050
(0.406 – 1.270)
.010 – .020
(0.254 – 0.508)
s 45°
0°– 8° TYP
.008 – .010
(0.203 – 0.254)
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
1
2
3
4
.150 – .157
(3.810 – 3.988)
NOTE 3
8
7
6
5
.189 – .197
(4.801 – 5.004)
NOTE 3
.228 – .244
(5.791 – 6.197)
.245
MIN
.160 ±.005
RECOMMENDED SOLDER PAD LAYOUT
.045 ±.005
.050 BSC
.030 ±.005
TYP
INCHES
(MILLIMETERS)
NOTE:
1. DIMENSIONS IN
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
8-Lead Plastic Small Outline (Narrow 0.150)
LT1129/LT1129-3.3/LT1129-5
S8 Package
(LTC DWG # 05-08-1610)
ST Package
3-Lead Plastic SOT-223
(LTC DWG # 05-08-1630)
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
112935ff
15
Page 16
LT1129/LT1129-3.3/LT1129-5
T5 (TO-220) 0801
.028 – .038
(0.711 – 0.965)
.067
(1.70)
.135 – .165
(3.429 – 4.191)
.700 – .728
(17.78 – 18.491)
.045 – .055
(1.143 – 1.397)
.095 – .115
(2.413 – 2.921)
.013 – .023
(0.330 – 0.584)
.620
(15.75)
TYP
.155 – .195*
(3.937 – 4.953)
.152 – .202
(3.861 – 5.131)
.260 – .320
(6.60 – 8.13)
.165 – .180
(4.191 – 4.572)
.147 – .155
(3.734 – 3.937)
DIA
.390 – .415
(9.906 – 10.541)
.330 – .370
(8.382 – 9.398)
.460 – .500
(11.684 – 12.700)
.570 – .620
(14.478 – 15.748)
.230 – .270
(5.842 – 6.858)
BSC
SEATING PLANE
* MEASURED AT THE SEATING PLANE
TYPICAL APPLICATION
5-Lead Plastic TO-220 (Standard)
(LTC DWG # 05-08-1421)
T Package
RELATED PARTS
PART NUMBER DESCRIPTION COMMENTS
LT1121 150mA LDO Micropower Regulator 30μA I
LT1761 100mA Low Noise, LDO Micropower Regulator 20μA I
LT1762 150mA Low Noise, LDO Micropower Regulator 25μA I
LT1962 300mA Low Noise, LDO Micropower Regulator 30μA IQ, 20μV
LT1763 500mA Low Noise, LDO Micropower Regulator 30μA I
LT1963 1.5A Low Noise, Fast Transient, LDO Regulator 340mV Dropout Voltage, 40μV
LT1764 3A Low Noise, Fast Transient, LDO Regulator 340mV Dropout Voltage, 40μV
Linear Technology Corporation
16
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
, SOT-223 Package
Q
, 20μV
Q
, 20μV
Q
, 20μ
Q
Noise
RMS
Noise
RMS
Noise
RMS
Noise
RMS
Noise
RMS
Noise
RMS
112935ff
LT 1208 REV F • PRINTED IN USA
© LINEAR TECHNOLOGY CORPORATION 1994
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