Datasheet

LT1170/LT1171/LT1172
7
117012fg
TYPICAL PERFORMANCE CHARACTERISTICS
Idle Supply Current vs Temperature
Feedback Pin Clamp Voltage Switch “Off” Characteristics
Shutdown Thresholds Flyback Blanking Time
Isolated Mode Flyback
Reference Voltage
Shutdown Mode Supply Current Error Amplifier Transconductance VC Pin Characteristics
V
C
PIN VOLTAGE (mV)
0
SUPPLY CURRENT (µA)
200
180
160
140
120
100
80
60
40
20
0
40
1170/1/2 G10
10
20
30
50
60
70
80
90 100
T
J
= 150°C
–55°C ≤ T
J
≤ 125°C
TEMPERATURE (°C)
TRANSCONDUCTANCE (µmho)
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
1170/1/2 G11
–75 –25
25
50 150
–50 0
75
100
125
g
m
=
$I (V
C
PIN)
$V (FB PIN)
V
C
PIN VOLTAGE (V)
300
200
100
0
–100
–200
–300
–400
1170/1/2 G12
V
C
PIN CURRENT (µA)
0 2.0
0.5
1.0
1.5
2.5
V
FB
= 1.5V (CURRENT INTO V
C
PIN)
V
FB
= 0.8V (CURRENT OUT OF V
C
PIN)
T
J
= 25°C
TEMPERATURE (°C)
IDLE SUPPLY CURRENT (mA)
11
10
9
8
7
6
5
4
3
2
1
1170/1/2 G13
–75 –25
25
50 150
–50 0
75
100
125
V
SUPPLY
= 60V
V
SUPPLY
= 3V
V
C
= 0.6V
FEEDBACK CURRENT (mA)
0
FEEDBACK VOLTAGE (mV)
500
450
400
350
300
250
200
150
100
50
0
0.4
1170/1/2 G14
0.1
0.2
0.3
0.5
0.6
0.7
0.8
0.9 1.0
–55°C
25°C
150°C
SWITCH VOLTAGE (V)
0
SWITCH CURRENT (µA)
1000
900
800
700
600
500
400
300
200
100
0
40
1170/1/2 G15
10
20
30
50
60
70
80
90 100
V
SUPPLY
= 55V
V
SUPPLY
= 3V
V
SUPPLY
= 15V
V
SUPPLY
= 40V
TEMPERATURE (°C)
V
C
PIN VOLTAGE (mV)
1170/1/2 G16
400
350
300
250
200
150
100
50
0
–75 –25
25
50 150
–50 0
75
100
125
–400
–350
–300
–250
–200
–150
–100
–50
0
V
C
PIN CURRENT (µA)
CURRENT (OUT OF V
C
PIN)
VOLTAGE
V
C
VOLTAGE IS REDUCED UNTIL
REGULATOR CURRENT DROPS
BELOW 300µA
JUNCTION TEMPERATURE (°C)
–75
TIME (µs)
–25
25
50 150
1170/1/2 G17
–50 0
75
100
125
2.2
2.0
1.8
1.6
1.4
1.2
1.0
TEMPERATURE (°C)
FLYBACK VOLTAGE (V)
1170/1/2 G18
23
22
21
20
19
18
17
16
15
–75 –25
25
50 150
–50 0
75
100
125
R
FB
= 500Ω
R
FB
= 1k
R
FB
= 10k