LT1175
elecTrical characTerisTics
PARAMETER
Feedback Sense Voltage
Output Voltage Initial Accuracy
Output Voltage Accuracy (All Conditions)
Quiescent Input Supply Current
GND Pin Current Increase with Load (Note 4)
Input Supply Current in Shutdown
Shutdown Thresholds (Note 9)
SHDN
Pin Current (Note 2)
Output Bleed Current in Shutdown (Note 6)
SENSE Pin Input Current
Dropout Voltage (Note 7)
V
SHDN
= 0V
l
The
l
denotes specifications which apply over the operating temperature
range, otherwise specifications are at T
A
= 25°C. V
OUT
= 5V, V
IN
= 7V, I
OUT
= 0, V
SHDN
= 3V, I
LIM2
and I
LIM4
tied to V
IN
, T
J
= 25°C, unless
otherwise noted. To avoid confusion with “min” and “max” as applied to negative voltages, all voltages are shown as absolute values
except where polarity is not obvious.
CONDITIONS
Adjustable Part
Fixed 5V Part
Adjustable, Measured at 3.8V Sense
Fixed 5V
V
IN
– V
OUT
= 1V to V
IN
= 20V, I
OUT
= 0A to 500mA
P = 0 to P
MAX
, T
J
= T
MIN
to T
MAX
(Note 3)
V
IN
– V
OUT
≤ 12V
l
l
l
MIN
3.743
4.93
TYP
3.8
5.0
0.5
0.5
1.5
45
10
10
MAX
3.857
5.075
1.5
1.5
2.5
65
80
20
20
25
2.5
8
4
1
5
150
20
0.2
0.26
0.7
0.5
0.45
0.45
1300
975
650
325
0.015
0.35
0.1
0.2
1.25
UNITS
V
V
%
%
%
µA
µA
µA/mA
µA
µA
V
µA
µA
µA
µA
nA
µA
V
V
V
V
V
V
mA
mA
mA
mA
%/V
%
%/W
%/W
%
Either Polarity On
SHDN
Pin
V
SHDN
= 0V to 10V (Flows Into Pin)
V
SHDN
= –15V to 0V (Flows Into Pin)
V
OUT
= 0V, V
IN
= 15V
l
l
0.8
4
1
0.1
1
75
12
0.1
0.18
0.5
0.33
0.3
0.26
520
390
260
130
800
600
400
200
0.003
0.1
0.04
0.1
0.25
l
(Adjustable Part Only, Current Flows Out of Pin)
(Fixed Voltage Only, Current Flows Out of Pin)
I
OUT
= 25mA
I
OUT
= 100mA
I
OUT
= 500mA
I
LIM2
Open, I
OUT
= 300mA
I
LIM4
Open, I
OUT
= 200mA
I
LIM2
, I
LIM4
Open, I
OUT
= 100mA
V
IN
– V
OUT
= 1V to 12V
I
LIM2
Open
I
LIM4
Open
I
LIM2
, I
LIM4
Open
V
IN
– V
OUT
= 1V to V
IN
= 20V
I
OUT
= 0mA to 500mA
P = 0 to P
MAX
(Notes 3, 8)
T
J
= 25°C to T
JMIN
, or 25°C to T
JMAX
5-Pin Packages
8-Pin Packages
l
l
l
l
l
l
l
l
l
l
l
l
l
l
Current Limit (Note 11)
Line Regulation (Note 10)
Load Regulation (Note 5, 10)
Thermal Regulation
Output Voltage Temperature Drift
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:
SHDN
pin maximum positive voltage is 30V with respect to
– V
IN
and 13.5V with respect to GND. Maximum negative voltage is –20V
with respect to GND and –5V with respect to –V
IN
.
Note 3:
P
MAX
= 1.5W for 8-pin packages, and 6W for 5-pin packages.
This power level holds only for input-to-output voltages up to 12V, beyond
which internal power limiting may reduce power. See Guaranteed Current
Limit curve in Typical Performance Characteristics section. Note that all
conditions must be met.
Note 4:
GND pin current increases because of power transistor base
drive. At low input-to-output voltages (<1V) where the power transistor
is in saturation, GND pin current will be slightly higher. See Typical
Performance Characteristics.
Note 5:
With I
LOAD
= 0, at T
J
> 125°C, power transistor leakage could
increase higher than the 10µA to 25µA drawn by the output divider or fixed
voltage SENSE pin, causing the output to rise above the regulated value.
To prevent this condition, an internal active pull-up will automatically turn
on, but supply current will increase.
Note 6:
This is the current required to pull the output voltage to within 1V
of ground during shutdown.
Note 7:
Dropout voltage is measured by setting the input voltage equal to
the normal regulated output voltage and measuring the difference between
V
IN
and V
OUT
. For currents between 100mA and 500mA, with both I
LIM
pins tied to V
IN
, maximum dropout can be calculated from
V
DO
= 0.15 + 1.1Ω (I
OUT
).
1175fe
LINER [ LINEAR TECHNOLOGY ]
