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