Datasheet

3
LT1528
1528fa
PARAMETER CONDITIONS MIN TYP MAX UNITS
GND Pin Current (Note 6) I
LOAD
= 0mA 450 750 µA
I
LOAD
= 0mA, T
J
= 125°C (Note 7) 1.9 mA
I
LOAD
= 100mA 1.2 2.5 mA
I
LOAD
= 100mA, T
J
= 125°C (Note 7) 2.7 mA
I
LOAD
= 300mA 2.6 4.0 mA
I
LOAD
= 300mA, T
J
= 125°C (Note 7) 4.1 mA
I
LOAD
= 700mA 7.3 12.0 mA
I
LOAD
= 700mA, T
J
= 125°C (Note 7) 8.8 mA
I
LOAD
= 1.5A ● 22 40 mA
I
LOAD
= 3A ● 85 140 mA
SENSE Pin Current (Notes 4, 8) 90 130 250 µA
SHDN Threshold V
OUT
= Off-to-On ● 1.20 2.80 V
V
OUT
= On-to-Off ● 0.25 0.75 V
SHDN Pin Current (Note 9) V
SHDN
= 0V ● 37 100 µA
Quiescent Current in Shutdown (Note 10) V
IN
= 6V, V
SHDN
= 0V ● 110 220 µA
Ripple Rejection V
IN
– V
OUT
= 1V(Avg), V
RIPPLE
= 0.5V
P-P
,5067 dB
f
RIPPLE
= 120Hz, I
LOAD
= 1.5A
Current Limit V
IN
– V
OUT
= 7V 4.5 A
V
IN
= 4.3V, ∆V
OUT
= – 0.1V ● 3.2 4.0 A
Input Reverse Leakage Current V
IN
= –15V, V
OUT
= 0V ● 1.0 mA
Reverse Output Current (Note 11) V
OUT
= 3.3V, V
IN
= 0V 120 250 µA
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The SHDN pin input voltage rating is required for a low impedance
source. Internal protection devices connected to the SHDN 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 SHDN pin must be less than 5mA.
Note 3: 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 must be limited.
When operating at maximum output current, the input voltage range
must be limited.
Note 4: The LT1528 is tested and specified with the SENSE pin connected
to the OUTPUT pin.
Note 5: 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
).
Note 6: GND 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 GND pin current. The GND pin
current will decrease slightly at higher input voltages.
Note 7: GND pin current will rise at T
J
> 75°C. This is due to internal
circuitry designed to compensate for leakage currents in the output
transistor at high temperatures. This allows quiescent current to be
minimized at lower temperatures, yet maintain output regulation at high
temperatures with light loads. See quiescent current curve in typical
performance characteristics section.
Note 8: SENSE pin current flows into the SENSE pin.
Note 9: SHDN pin current at V
SHDN
= 0V flows out of the SHDN pin.
Note 10: Quiescent current in shutdown is equal to the total sum of the
SHDN pin current (40µA) and the GND pin current (70µA).
Note 11: Reverse output current is tested with the input pin grounded and
the OUTPUT pin forced to the rated output voltage. This current flows into
the OUTPUT pin and out of the GND pin.
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T
J
= 25°C.
ELECTRICAL CHARACTERISTICS