Datasheet

4
LT1370
sn1370 1370fs
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
Switching Frequency
vs Feedback Pin Voltage
VOLTAGE (V)
–1
INPUT CURRENT (µA)
1
7
LT1370 • G07
–1
–3
0
2
–2
–4
1
3
5
0
2
4
6
FEEDBACK PIN VOLTAGE (V)
0
SWITCHING FREQUENCY (% OF TYPICAL)
70
90
110
0.8
LT1370 • 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
Switch Saturation Voltage
vs Switch Current
DUTY CYCLE (%)
6.6
SWITCH CURRENT LIMIT (A)
7.4
7.2
7.8
8.2
7.0
6.8
7.6
8.0
20 40 60 80
LT1370 • G02
10010
0
30 50 70 90
Switch Current Limit
vs Duty Cycle
SWITCH CURRENT (A)
0
SWITCH VOLTAGE (mV)
300
400
550
5
LT1370 • G01
200
100
250
350
450
500
150
50
0
1
23
4
6
125°C
75°C
25°C
0°C
TEMPERATURE (°C)
–50
1.8
INPUT VOLTAGE (V)
2.0
2.2
2.4
2.6
050
100
150
LT1370 • G03
2.8
3.0
–25 25
75
125
Minimum Input Voltage
vs Temperature
TEMPERATURE (°C)
–50
0
SHUTDOWN DELAY (µs)
SHUTDOWN THRESHOLD (V)
2
6
8
10
20
14
0
50
75
LT1370 • 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
Shutdown Delay and Threshold
vs Temperature
Error Amplifier Output Current
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
LT1370 • G06
TEMPERATURE (°C)
–50
0
MINIMUM SYNCHRONIZATION VOLTAGE (V
P-P
)
0.5
1.0
1.5
2.0
050
100
150
LT1370 • G05
2.5
3.0
–25 25
75
125
f
SYNC
= 700kHz
Minimum Synchronization
Voltage vs Temperature
Error Amplifier Transconductance
vs Temperature
TEMPERATURE (°C)
–50
0
TRANSCONDUCTANCE (µmho)
200
600
800
1000
2000
1400
0
50
75
LT1370 • G09
400
1600
1800
1200
–25 25
100
125
150
g
m
=
∆I (V
C
)
∆V (FB)
S/S Pin Input Current vs Voltage