LT1172MJ8 Linear Technology, LT1172MJ8 Datasheet - Page 5

• Manufacturer Part Number: LT1172MJ8
• Description: SP-SWREG/Monolithic, 100kHz 5A 2.5A And 1.25A High Efficiency Switching Regulato
• Manufacturer: Linear Technology

TYPICAL PERFOR A CE CHARACTERISTICS
160
140
120
100
–1
–2
–3
–4
–5
80
60
40
20
16
12
5
4
3
2
1
0
0
8
4
0
0
0
0
Line Regulation
Supply Current vs Supply Voltage
(Shutdown Mode)
Switch Current Limit vs Duty Cycle*
T
* DIVIDE VERTICAL SCALE BY TWO FOR
T
J
10
LT1171, BY FOUR FOR LT1172.
J
= 25 C
= –55 C
10
10
20 30
–55 C
125 C
SUPPLY VOLTAGE (V)
INPUT VOLTAGE (V)
20
20
DUTY CYCLE (%)
40
V
C
V
C
= 50mV
30
30
50 60 70 80 90 100
= 0V
25 C
40
40
T
J
T
= 150 C
J
W
= 25 C
50
50
1170/1/2 G04
1170/1/2 G07
1170/1/2 G01
U
60
60
1.250
1.248
1.246
1.244
1.242
1.240
1.238
1.236
1.234
160
140
120
100
* AVERAGE LT1170 POWER SUPPLY CURRENT IS
80
60
40
20
2.9
2.8
2.7
2.6
2.5
2.4
2.3
FOUND BY MULTIPLYING DRIVER CURRENT BY
DUTY CYCLE, THEN ADDING QUIESCENT CURRENT.
0
–75
–75
0
Reference Voltage vs Temperature
Driver Current* vs Switch Current
Minimum Input Voltage
–50
–50
–25
SWITCH CURRENT = 0A
1
–25
SWITCH CURRENT (A)
TEMPERATURE ( C)
TEMPERATURE ( C)
SWITCH CURRENT = I
0
0
2
25
25
T
J
= – 55 C
50
50
3
T
75 100 125
75 100 125
J
= 25 C
MAX
4
1170/1/2 G02
1170/1/2 G08
1170/1/2 G05
150
150
5
LT1 170/LT1 171/LT1172
* UNDER VERY LOW OUTPUT CURRENT CONDITIONS,
DUTY CYCLE FOR MOST CIRCUITS WILL APPROACH
10% OR LESS.
800
700
600
500
400
300
200
100
15
14
13
12
11
10
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
9
8
7
6
5
0
0
–75
Supply Current vs Input Voltage*
0
0
Feedback Bias Current vs
Temperature
Switch Saturation Voltage
T
NOTE THAT THIS CURRENT DOES NOT
INCLUDE DRIVER CURRENT, WHICH IS
A FUNCTION OF LOAD CURRENT AND
DUTY CYCLE.
–50
J
= 25 C
1
10
–25
* DIVIDE CURRENT BY TWO FOR
2
SWITCH CURRENT (A)*
INPUT VOLTAGE (V)
LT1171, BY FOUR FOR LT1172.
TEMPERATURE ( C)
20
0
3
25
30
4
50
90% DUTY CYCLE
50% DUTY CYCLE
10% DUTY CYCLE
0% DUTY CYCLE
5
100 C
75 100 125
40
6
150 C
–55 C
50
1170/1/2 G06
1170/1/2 G09
1170/1/2 G03
117012ff
25 C
7
5
150
60
8