LT1082_1 Datasheet, PDF (5/12 Pages) Linear Integrated Systems – 1A High Voltage, Efficiency Switching Voltage Regulator

TYPICAL PERFOR A CE CHARACTERISTICS
LT1082
Isolated Mode Flyback
Reference Voltage
25
24
23
R_FB = 3k
22
21
20
R_FB = 6k
19
R_FB = 10k
18
17
16
15
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
1082 G09
Feedback Bias Current vs
Temperature
800
700
600
500
400
300
200
100
0
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
1082 G12
Supply Current vs Supply Voltage
(Shutdown Mode)
200
160
V_C = 50mV
120
80
V_C = 0V
40
0
0 10 20 30 40 50 60 70 80
SUPPLY VOLTAGE (V)
1082 G15
Reference Voltage and Switching
Frequency vs Temperature
70
1.250
65
V_REF
FREQ
60
1.245
1.240
55
1.235
50
1.230
45
1.225
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
1082 G11
Normal/Feedback Mode
Threshold on Feedback Pin
750
– 24
725 _{FEEDBACK PIN VOLTAGE}
– 22
700 ^{(AT THRESHOLD)}
– 20
675
– 18
650
– 16
625
– 14
600
– 12
575 ^{FEEDBACK PIN CURRENT}
– 10
(AT THRESHOLD)
550
–8
525
–6
500
–4
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
1082 G16
Line Regulation
5
4
3
2
1
0 ^{TJ = –55°C}
–1
–2
T_J = 150°C
–3
T_J = 25°C
–4
–5
0
10 20 30 40 50 60
INPUT VOLTAGE (V)
70 80
1082 G10
Shutdown Mode Supply Current
200
180
–55°C ≤ T_J ≤ 125°C
160
140
T_J = 150°C
120
100
80
60
40
20
0
0 10 20 30 40 50 60 70 80 90 100
V_C PIN VOLTAGE (mV)
1082 G17
Driver Current* vs Switch Current
100
90
80
70
60
50
40
30
20
10
0
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
SWITCH CURRENT (A)
* AVERAGE SUPPLY CURRENT
= I_Q + DC(2.9 + 10^–2I_SW + 10 ^–5 I_SW²)
I_Q = QUIESCENT CURRENT, DC = DUTY CYCLE,
I_SW = SWITCH CURRENT
1082 G13
Supply Current vs Input Voltage**
14
13
12
11
10
90% DUTY CYCLE
9
8
7
50% DUTY CYCLE
6
10% DUTY CYCLE
5
4
0% DUTY CYCLE
3
2
0 10 20 30 40 50 60 70 80
INPUT VOLTAGE (V)
**UNDER VERY LOW OUTPUT CURRENT CONDITIONS,
DUTY CYCLE FOR MOST CIRCUITS WILL APPROACH
10% OR LESS.
1082 G14
sn1082 1082fas
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