LT1129/LT1129-3.3/LT1129-5
ELECTRICAL CHARACTERISTICS
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
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
J
> 110°C and I
OUT
< 1mA, output voltage
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
voltage will be equal to (V
IN
– V
DROPOUT
). Dropout voltage is measured
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
IN
= V
OUT
(nominal) and a
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
SHDN
= 0V flows out of the shutdown pin.
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 12:
For C-grade devices Regulated Output Voltage, Line Regulation,
and Load Regulation are guaranteed over the extended temperature range
of – 40°C to 125°C. These parameters are not tested or quality assurance
sampled at –40°C. They are guaranteed by design, correlation and/or
inference from 25°C and/or 0°C tests.
112935fc
4
LINEAR [ LINEAR INTEGRATED SYSTEMS ]
