LT1
170/LT1
171/LT1172
TYPICAL PERFOR A CE CHARACTERISTICS
Line Regulation
5
1.250
REFERENCE VOLTAGE CHANGE (mV)
4
REFERENCE VOLTAGE (V)
3
2
1
0
–1
–2
–3
–4
–5
0
10
T
J
= –55°C
T
J
= 150°C
FEEDBACK BIAS CURRENT (nA)
T
J
= 25°C
30
40
20
INPUT VOLTAGE (V)
Supply Current vs Supply Voltage
(Shutdown Mode)
160
T
J
= 25°C
140
SUPPLY CURRENT (mA)
SUPPLY CURRENT (µA)
DRIVER CURRENT (mA)
120
100
80
60
40
20
0
0
10
30
20
40
SUPPLY VOLTAGE (V)
50
60
V
C
= 0V
V
C
= 50mV
Shutdown Mode Supply Current
200
180
160
TRANSCONDUCTANCE (µmho)
SUPPLY CURRENT (µA)
V
C
PIN 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
T
J
= 150°C
–55°C
≤
T
J
≤
125°C
U W
50
1170/1/2 G04
1170/1/2 G07
Reference Voltage vs Temperature
800
700
600
500
400
300
200
100
1.248
1.246
1.244
1.242
1.240
1.238
1.236
1.234
–75 –50 –25
Feedback Bias Current vs
Temperature
60
25 50 75 100 125 150
TEMPERATURE (°C)
0
1170/1/2 G05
0
–75 –50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
1170/1/2 G06
Driver Current* vs Switch Current
160
140
120
100
80
60
40
20
0
0
1
2
3
SWITCH CURRENT (A)
4
5
1170/1/2 G08
Supply Current vs Input Voltage*
15
14
13
12
11
10
9
8
7
6
5
0
10
30
40
20
INPUT VOLTAGE (V)
50
60
1170/1/2 G09
T
J
= 25°C
NOTE THAT THIS CURRENT DOES NOT
INCLUDE DRIVER CURRENT, WHICH IS
A FUNCTION OF LOAD CURRENT AND
DUTY CYCLE.
90% DUTY CYCLE
50% DUTY CYCLE
10% DUTY CYCLE
0% DUTY CYCLE
T
J
= –55°C
T
J
=
≥
25°C
* AVERAGE LT1170 POWER SUPPLY CURRENT IS
FOUND BY MULTIPLYING DRIVER CURRENT BY
DUTY CYCLE, THEN ADDING QUIESCENT CURRENT.
* UNDER VERY LOW OUTPUT CURRENT CONDITIONS,
DUTY CYCLE FOR MOST CIRCUITS WILL APPROACH
10% OR LESS.
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
V
C
Pin Characteristics
300
200
100
0
T
J
= 25°C
–100
–200
V
FB
= 0.8V (CURRENT OUT OF V
C
PIN)
–300
–400
0
0.5
1.5
2.0
1.0
V
C
PIN VOLTAGE (V)
2.5
V
FB
= 1.5V (CURRENT INTO V
C
PIN)
∆I
(V
C
PIN)
g
m
=
∆V
(FB PIN)
1170/1/2 G12
5
LINER [ LINEAR TECHNOLOGY ]
