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
200
180
160
140
120
100
–1
–2
–3
–4
–5
80
60
40
20
80
60
40
20
5
4
3
2
1
0
0
0
0
0
0
Line Regulation
Supply Current vs Supply Voltage
(Shutdown Mode)
Shutdown Mode Supply Current
T
10 20 30
T
J
J
= 25 C
= –55 C
10
10
SUPPLY VOLTAGE (V)
V
INPUT VOLTAGE (V)
C
20
20
T
PIN VOLTAGE (mV)
J
40
= 150 C
V
C
–55 C T
V
C
= 50mV
50 60 70 80 90 100
30
30
= 0V
J
40
40
T
J
T
125 C
= 150 C
J
W
= 25 C
50
50
1170/1/2 G04
1170/1/2 G07
1170/1/2 G10
U
60
60
1.250
1.248
1.246
1.244
1.242
1.240
1.238
1.236
1.234
5000
4500
4000
3500
3000
2500
2000
1500
1000
160
140
120
100
500
* AVERAGE LT1170 POWER SUPPLY CURRENT IS
80
60
40
20
FOUND BY MULTIPLYING DRIVER CURRENT BY
DUTY CYCLE, THEN ADDING QUIESCENT CURRENT.
0
0
–75
–75
0
Reference Voltage vs Temperature
Driver Current* vs Switch Current
Error Amplifier Transconductance
–50
–50
–25
1
–25
SWITCH CURRENT (A)
TEMPERATURE ( C)
TEMPERATURE ( C)
0
0
2
25
25
T
J
= –55 C
50
50
3
g
m
T
75 100 125
75 100 125
J
=
= 25 C
V (FB PIN)
I (V
4
C
1170/1/2 G08
1170/1/2 G05
1170/1/2 G11
PIN)
150
150
5
LT1 170/LT1 171/LT1172
* UNDER VERY LOW OUTPUT CURRENT CONDITIONS,
–100
–200
–300
–400
DUTY CYCLE FOR MOST CIRCUITS WILL APPROACH
10% OR LESS.
300
200
100
800
700
600
500
400
300
200
100
15
14
13
12
11
10
9
8
7
6
5
0
0
–75
0
Supply Current vs Input Voltage*
0
Feedback Bias Current vs
Temperature
V
V
C
T
NOTE THAT THIS CURRENT DOES NOT
INCLUDE DRIVER CURRENT, WHICH IS
A FUNCTION OF LOAD CURRENT AND
DUTY CYCLE.
FB
–50
J
Pin Characteristics
V
= 25 C
= 1.5V (CURRENT INTO V
FB
10
0.5
= 0.8V (CURRENT OUT OF V
–25
V
INPUT VOLTAGE (V)
TEMPERATURE ( C)
20
C
0
PIN VOLTAGE (V)
T
1.0
J
25
= 25 C
30
50
90% DUTY CYCLE
50% DUTY CYCLE
10% DUTY CYCLE
1.5
0% DUTY CYCLE
75 100 125
40
C
PIN)
2.0
C
50
PIN)
1170/1/2 G12
1170/1/2 G06
1170/1/2 G09
5
150
2.5
60