LT1082
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Idle Supply Current vs
Temperature
Shutdown Thresholds
Error Amplifier Transconductance
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
400
350
300
250
200
150
100
50
–400
–350
–300
–250
–200
–150
–100
–50
10
9
V
C
= 0.6V
(V PIN)
C
∆I
∆V
g
=
m
(FB PIN)
CURRENT
(OUT OF V PIN)
8
C
7
6
V
= 75V
= 3V
IN
VOLTAGE AT V PIN
5
C
V
IN
4
3
2
0
–75
0
175
0
–75
1
0
50 75 100 125 150
–75
0
50 75 100 125 150
175
–50 –25
25
–50 –25
25
0
50 75 100 125 150
–50 –25
25
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
1082 G18
1082 G19
1082 G20
Feedback Pin Clamp Voltage
Switch “Off” Characteristics
800
700
600
500
400
300
200
500
450
400
350
300
250
200
150
100
50
A. V = 3V
IN
B. V = 15V
IN
C. V = 40V
IN
T = –55°C
J
D. V = 55V
IN
E. V = 75V
IN
T = 25°C
J
T = 150°C
J
A
B
C
D
E
0
0
0.1 0.2
0.5
0.7 0.8 0.9
1.1
0
30
0.3 0.4
0.6
1.0
10 20
40
50 60 70 80 90
100
FEEDBACK CURRENT (mA)
SWITCH VOLTAGE (V)
1082 G21
1082 G22
Transconductance of Error
Amplifier
VC Pin Characteristics
7000
6000
5000
4000
3000
2000
1000
0
–30
400
300
T = 25°C
J
0
θ
V
= 1.5V
30
200
FB
(CURRENT INTO V PIN)
C
g
m
60
100
90
0
120
150
180
210
–100
–200
–300
–400
V
= 0.8V
FB
(CURRENT OUT OF V PIN)
C
–1000
1k
10k
100k
FREQUENCY (Hz)
1M
10M
0
2.0
0.5
1.0
1.5
PIN VOLTAGE (V)
2.5
V
C
1082 G24
1082 G23
sn1082 1082fas
6