Datasheet

6
LT1170/LT1171/LT1172
117012ff
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
Shutdown Mode Supply Current
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)
Error Amplifier Transconductance V
C
Pin Characteristics
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
TYPICAL PERFOR A CE CHARACTERISTICS
UW
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
Isolated Mode Flyback
Reference Voltage
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
Flyback Blanking TimeShutdown Thresholds
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 Pin Clamp Voltage Switch “Off” Characteristics
Idle Supply Current vs
Temperature
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