LT1129/LT1129-3.3/LT1129-5
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C.
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Ripple Rejection
V
– V
= 1V (Avg), V
= 0.5V ,
P-P
52
64
dB
IN
OUT
RIPPLE
f
= 120Hz, I
= 0.7A, T = 25°C
LOAD J
RIPPLE
Current Limit
V
– V
= 7V, T = 25°C
1.2
1.6
1.0
A
IN
IN
OUT
J
l
Input Reverse Leakage Current
Reverse Output Current (Note 11)
V
= –20V, V
= 0V
mA
OUT
LT1129-3.3
LT1129-5
LT1129 (Note 5)
V
= 3.3V, V = 0V
16
16
16
25
25
25
μA
μA
μA
OUT
OUT
OUT
IN
V
V
= 5V, V = 0V
IN
= 3.8V, V = 0V
IN
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.
voltage will be equal to (V – V
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.
). Dropout voltage is measured
IN
DROPOUT
Note 7: Ground pin current is tested with V = V
(nominal) and a
IN
OUT
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.
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 flows into the adjust pin.
Note 9: Shutdown pin current at V
= 0V flows 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 flows 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 3: For junction temperatures greater than 110°C, a minimum load
of 1mA is recommended. For T > 110°C and I
< 1mA, output voltage
J
OUT
may increase by 1%.
Note 4: Operating conditions are limited by maximum junction
temperature. The regulated output voltage specification 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 specified 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 specified output current. In dropout the output
Note 12: The LT1129 regulators are tested and specified under pulse load
conditions such that T ≅ T . The LT1129C regulators are 100% tested at
J
A
T = 25°C. For C-grade devices, Regulated Output Voltage, Line Regulation
A
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.
TYPICAL PERFORMANCE CHARACTERISTICS
Guaranteed Dropout Voltage
Dropout Voltage
Quiescent Current
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
70
60
50
40
30
20
10
0
A. I
B. I
C. I
D. I
= 700mA
= 500mA
= 300mA
= 100mA
= 10mA
LOAD
LOAD
LOAD
LOAD
LOAD
A
B
T ≤ 125°C
J
V
= OPEN (HI)
SHDN
E. I
T ≤ 25°C
J
C
D
E
V
= 0V
SHDN
= TEST POINTS
0
0.2
0.3 0.4
0.5 0.6 0.7
–50
0
25
50
75 100 125
–50
0
25
50
75
125
0.1
–25
–25
100
OUTPUT CURRENT (A)
TEMPERATURE (°C)
TEMPERATURE (°C)
112935 G03
112935 G01
112935 G02
112935ff
5
Linear [ Linear ]
