Datasheet

4
LT1371
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
Error Amplifier Output Current
vs Feedback Pin Voltage
Shutdown Delay and Threshold
vs Temperature
TEMPERATURE (°C)
–50
0
SHUTDOWN DELAY (µs)
SHUTDOWN THRESHOLD (V)
2
6
8
10
20
14
0
50
75
LT1371 • G04
4
16
18
12
0
0.2
0.6
0.8
1.0
2.0
1.4
0.4
1.6
1.8
1.2
–25 25
100
125
150
SHUTDOWN THRESHOLD
SHUTDOWN DELAY
S/S or SHDN Pin Input Current
vs Voltage
Error Amplifier Transconductance
vs Temperature
Switching Frequency
vs Feedback Pin Voltage
FEEDBACK PIN VOLTAGE (V)
400
ERROR AMPLIFIER OUTPUT CURRENT (µA)
–300
–200
–100
300
100
–0.1 0.1
200
0
–0.3 –0.2
V
REF
–55°C
125°C
25°C
LT1371 • G06
Minimum Synchronization
Voltage vs Temperature
TEMPERATURE (°C)
–50
0
MINIMUM SYNCHRONIZATION VOLTAGE (V
P-P
)
0.5
1.0
1.5
2.0
050
100
150
LT1371 • G05
2.5
3.0
–25 25
75
125
f
SYNC
= 700kHz
VOLTAGE (V)
–1
INPUT CURRENT (µA)
1
3
5
7
LT1371 • G07
–1
–3
0
2
4
–2
–4
–5
1
3
5
08
2
4
6
9
V
IN
= 5V
FEEDBACK PIN VOLTAGE (V)
0
SWITCHING FREQUENCY (% OF TYPICAL)
70
90
110
0.8
LT1371 • G08
50
30
60
80
100
40
20
10
0.2
0.4
0.6
0.1 0.9
0.3
0.5
0.7
1.0
TEMPERATURE (°C)
–50
0
TRANSCONDUCTANCE (µmho)
200
600
800
1000
2000
1400
0
50
75
LT1371 • G09
400
1600
1800
1200
–25 25
100
125
150
g
m
=
∆I (V
C
)
∆V (FB)
Switch Saturation Voltage
vs Switch Current
TEMPERATURE (°C)
–50
1.8
INPUT VOLTAGE (V)
2.0
2.2
2.4
2.6
050
100
150
LT1371 • G03
2.8
3.0
–25 25
75
125
Minimum Input Voltage
vs Temperature
DUTY CYCLE (%)
0
SWITCH CURRENT LIMIT (A)
2
4
6
1
3
5
20 40 60 80
LT1371 • G02
10010
0
30 50 70 90
25°C AND
125°C
–55°C
Switch Current Limit
vs Duty Cycle
SWITCH CURRENT (A)
0
SWITCH SATURATION VOLTAGE (V)
0.6
0.8
1.0
3.2
LT1371 • G01
0.4
0.2
0.5
0.7
0.9
0.3
0.1
0
0.8
1.6
2.4
4.0
2.8
0.4
1.2
2.0
3.6
100°C
150°C
25°C
–55°C