LT1175
TYPICAL PERFORMANCE CHARACTERISTICS
Shutdown Input Current
25
2.5
POSITIVE THRESHOLD
PIN CURRENT (μA)
Shutdown Thresholds
15
SHDN
Pin Characteristics
V
IN
= 25V
CHARACTERISTICS DO NOT
CHANGE SIGNIFICANTLY WITH
TEMPERATURE, SO A SINGLE
CURVE IS SHOWN. POSITIVE
CURRENT FLOWS INTO
SHDN PIN
20
INPUT CURRENT (μA)
THRESHOLD (V)
2.0
10
15
T
J
= 25°C
T
J
= 125°C
10
T
J
= –55°C
5
1.5
NEGATIVE THRESHOLD
1.0
5
0
IF SHDN PIN IS NEGATIVE WITH
RESPECT TO INPUT VOLTAGE AND
INPUT VOLTAGE IS LESS THAN 15V,
NEGATIVE BREAKOVER POINT WILL
BE ABOUT 8V BELOW –V
IN
0.5
DEVICE IS OFF
BELOW THRESHOLD
–5
0
0
5
15
10
INPUT VOLTAGE (V)
20
25
1175 G07
0
–50
–25
25
50
0
75
TEMPERATURE (°C)
100
125
–10
–25 –20 –15 –10 –5 0 5 10 15 20 25
SHUTDOWN TO GROUND VOLTAGE (V)
1175 G09
1175 G08
GND Pin Current
20
100
Ripple Rejection
V
OUT
= 12V
(ADJUSTABLE)
WITH 0.1μF ACROSS
DIVIDER RESISTOR
V
OUT
= 5V
(FIXED)
V
OUT
= 12V
(ADJUSTABLE)
GROUND PIN CURRENT (mA)
16
REJECTION (dB)
80
12
POWER
TRANSISTOR
IN DROPOUT
T
J
= –55°C
T
J
= 25°C
V
IN
– V
OUT
= 2V
T
J
= 25°C
60
8
40
4
20
V
IN
– V
OUT
≥ 3V
T
J
= 25°C
I
OUT
= 100mA
V
IN
– V
OUT
= 2V
C
OUT
= 1μF TANT
10
100
1k
10k
FREQUENCY (Hz)
100k
1M
0
0
0.1
0
0.2 0.3 0.4
0.5
OUTPUT CURRENT (A)
0.6
0.7
1175 G10
RIPPLE REJECTION IS RELATIVELY INDEPENDENT OF
INPUT VOLTAGE AND LOAD FOR CURRENTS BETWEEN
25mA AND 500mA. LARGER OUTPUT CAPACITORS DO
NOT IMPROVE REJECTION FOR FREQUENCIES BELOW
50kHz. AT VERY LIGHT LOADS, REJECTION WILL
IMPROVE WITH LARGER OUTPUT CAPACITORS
1175 G11
1175ff
7
LINER [ LINEAR TECHNOLOGY ]
