LT1528 Linear Technology, LT1528 Datasheet - Page 3

• Manufacturer Part Number: LT1528
• Description: 3A Low Dropout Regulator for Microprocessor Applications
• Manufacturer: Linear Technology

PARAMETER
Ground Pin Current (Note 5)
Sense Pin Current (Notes 3, 7)
Shutdown Threshold
Shutdown Pin Current (Note 8)
Quiescent Current in Shutdown (Note 9)
Ripple Rejection
Current Limit
Input Reverse Leakage Current
Reverse Output Current (Note 10)
The
temperature range.
Note 1: 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 less than
5mA.
Note 2: 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 3: The LT1528 is tested and specified with the Sense pin connected
to the Output pin.
ELECTRICAL CHARACTERISTICS
denotes specifications which apply over the full operating
CONDITIONS
I
T
V
V
I
I
I
I
I
I
I
I
I
V
V
V
V
f
V
V
V
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
RIPPLE
J
OUT
OUT
SHDN
IN
IN
IN
IN
IN
OUT
= 25 C
= 6V, V
– V
– V
= 4.3V, V
= – 15V, V
= Off-to-On
= On-to-Off
= 3.3V, V
= 0mA, T
= 0mA, T
= 100mA, T
= 100mA, T
= 300mA, T
= 300mA, T
= 700mA, T
= 700mA, T
= 1.5A
= 3A
= 0V
OUT
OUT
= 120Hz, I
SHDN
= 1V(Avg), V
= 7V, T
OUT
OUT
IN
J
J
= 0V
= 25 C
= 125 C (Note 6)
= 0V
LOAD
= 0V
J
J
J
J
J
J
J
= – 0.1V
= 25 C
= 125 C (Note 6)
= 25 C
= 125 C (Note 6)
= 25 C
= 125 C (Note 6)
= 25 C
= 1.5A
RIPPLE
Note 4: 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
Note 5: Ground pin current is tested with V
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 6: Ground pin current will rise at T
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 7: Sense pin current flows into the Sense pin.
Note 8: Shutdown pin current at V
Note 9: Quiescent current in shutdown is equal to the total sum of the
Shutdown pin current (40 A) and the Ground pin current (70 A).
Note 10: 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 Ground pin.
= 0.5V
P-P
,
IN
– V
DROPOUT
SHDN
MIN
0.25
3.2
90
50
= 0V flows out of the Shutdown pin.
J
).
> 75 C. This is due to internal
IN
= V
1.20
0.75
TYP
450
130
110
120
1.9
1.2
2.7
2.6
4.1
7.3
8.8
4.5
4.0
22
85
37
67
OUT
(nominal) and a
MAX
12.0
2.80
750
140
250
100
220
250
2.5
4.0
1.0
40
LT1528
UNITS
3
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
dB
A
A
V
V
A
A
A
A
A