Datasheet

4
LT1072
1072fc
Switch Current Limit vs Duty Cycle Maximum Duty Cycle Flyback Blanking Time
DUTY CYCLE (%)
0
SWITCH CURRENT (A)
4
3
2
1
0
80
LT1072 • TPC01
20 40 60 1007010 30 50 90
–55°C
125°C
25°C
JUNCTION TEMPERATURE (°C)
–75
90
DUTY CYCLE (%)
91
93
94
95
–25
25
50 150
LT1072 • TPC02
92
–50 0
75
100
125
96
JUNCTION TEMPERATURE (°C)
–75
1.0
TIME (µs)
1.2
1.6
1.8
2.0
–25
25
50 150
LT1072 • TPC03
1.4
–50 0
75
100
125
2.2
Minimum Input Voltage Switch Saturation Voltage
Isolated Mode Flyback Reference
Voltage
TEMPERATURE (°C)
–75
2.3
MINIMUM INPUT VOLTAGE (V)
2.4
2.6
2.7
2.8
–25
25
50 150
LT1072 • TPC04
2.5
–50 0
75
100
125
2.9
SWITCH CURRENT = 1.25A
SWITCH CURRENT = 0A
SWITCH CURRENT (A)
0
SWITCH SATURATION VOLTAGE (V)
0.8
1.2
2
LT1072 • TPC05
0.4
0
0.5
1
1.5
0.25
0.75
1.25
1.75
1.6
0.6
1.0
0.2
1.4
150°C
100°C
–55°C
25°C
TEMPERATURE (C°)
–75
FLYBACK VOLTAGE (V)
19
20
21
125
LT1072 • TPC06
18
17
15
–25
25
75
–50 150
0
50
100
16
23
22
R
FEEDBACK
= 500Ω
R
FEEDBACK
= 1kΩ
R
FEEDBACK
= 10kΩ
Line Regulation
Reference Voltage and Switching
Frequency vs Temperature
Feedback Bias Current vs
Temperature
INPUT VOLTAGE (V)
0
–5
REFERENCE VOLTAGE CHANGE (mV)
–3
–1
1
10
20
30 40
LT1072 • TPC07
50
3
5
–4
–2
0
2
4
60
T
J
= 150°C
T
J
= – 55°C
T
J
= 25°C
TEMPERATURE (°C)
–75
REFERENCE VOLTAGE (V)
FREQUENCY (kHz)
1.242
1.244
1.246
125
LT1072 • TPC08
1.240
1.238
1.234
–25
25
75
–50 150
0
50
100
1.236
1.250
1.248
38
39
40
37
36
34
35
42
41
REFERENCE VOLTAGE
SWITCHING FREQUENCY
TEMPERATURE (°C)
–75
FEEDBACK BIAS CURRENT (nA)
400
500
600
125
LT1072 • TPC09
300
200
0
–25
25
75
–50 150
0
50
100
100
800
700
TYPICAL PERFOR A CE CHARACTERISTICS
UW