LT1374
TYPICAL PERFOR A CE CHARACTERISTICS
Shutdown Supply Current
70
60
V
IN
= 25V
50
V
IN
= 10V
40
30
20
10
R
LOAD
= 50Ω
2500
INPUT SUPPLY CURRENT (µA)
TRANSCONDUCTANCE (µMho)
GAIN (µMho)
0
0
0.1
0.2
0.3
SHUTDOWN VOLTAGE (V)
0.4
1374 G07
Frequency Foldback
SWITCHING FREQUENCY (kHz) OR CURRENT (µA)
500
400
FREQUENCY (kHz)
520
510
500
490
480
470
300
INPUT VOLTAGE (V)
SWITCHING
FREQUENCY
200
100
FEEDBACK PIN
CURRENT
0
0
0.5
1.5
2.0
1.0
FEEDBACK PIN VOLTAGE (V)
2.5
1374 G10
Maximum Load Current
at V
OUT
= 10V
4.5
V
OUT
= 10V
L = 20µH
L = 10µH
CURRENT (A)
CURRENT (A)
CURRENT (A)
4.0
3.5
3.0
0
5
10
15
INPUT VOLTAGE (V)
U W
L = 5µH
20
1374 G13
Error Amplifier Transconductance
3000
Error Amplifier Transconductance
200
PHASE
2000
2500
GAIN
150
PHASE (DEG)
1500
2000
100
1000
1500
V
FB
2
×
10
–3
(
)
R
OUT
200k
V
C
C
OUT
12pF
50
500
1000
ERROR AMPLIFIER EQUIVALENT CIRCUIT
0
0
50
0
75 100
25
–50 –25
JUNCTION TEMPERATURE (°C)
125
500
100
1k
10k
100k
FREQUENCY (Hz)
1M
–50
10M
1374 G09
1374 G08
Switching Frequency
550
540
530
Minimum Input Voltage
with 5V Output
6.4
6.2
6.0
5.8
5.6
5.4
5.2
5.0
MINIMUM
RUNNING
VOLTAGE
MINIMUM
STARTING
VOLTAGE
460
450
– 50
–25
0
25
50
75
100
125
1
TEMPERATURE (°C)
1374 G11
10
100
LOAD CURRENT (mA)
1000
1374 G12
Maximum Load Current
at V
OUT
= 3.3V
4.5
L = 20µH
L = 10µH
4.0
4.0
4.5
Maximum Load Current
at V
OUT
= 5V
L = 20µH
L = 10µH
L = 5µH
L = 5µH
3.5
3.5
V
OUT
= 3.3V
3.0
25
3.0
V
OUT
= 5V
0
5
10
15
INPUT VOLTAGE (V)
20
25
1374 G14
0
5
10
15
INPUT VOLTAGE (V)
20
25
1374 G15
1374fb
5
LINER [ LINEAR TECHNOLOGY ]
