LT1172MJ8 Linear Technology, LT1172MJ8 Datasheet - Page 6

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

LT1 170/LT1 171/LT1172
TYPICAL PERFOR A CE CHARACTERISTICS
6
400
350
300
250
200
150
100
11
10
50
9
8
7
6
5
4
3
2
1
0
–75
–75
Idle Supply Current vs
Temperature
Shutdown Thresholds
V
–50
–50
C
CURRENT (OUT OF V
= 0.6V
V
REGULATOR CURRENT DROPS
BELOW 300 A
–25
–25
C
VOLTAGE IS REDUCED UNTIL
–1000
TEMPERATURE ( C)
TEMPERATURE ( C)
V
7000
6000
5000
4000
3000
2000
1000
V
0
0
SUPPLY
SUPPLY
VOLTAGE
0
25
25
1k
Transconductance of Error
Amplifier
= 60V
= 3V
50
50
C
PIN)
75 100 125
75 100 125
10k
W
FREQUENCY (Hz)
1170/1/2 G13
1170/1/2 G16
100k
U
150
150
g
m
– 400
– 350
– 300
– 250
– 200
– 150
–100
– 50
0
1M
500
450
400
350
300
250
200
150
100
50
1170/1/2 G19
0
0
Feedback Pin Clamp Voltage
2.2
2.0
1.8
1.6
1.4
1.2
1.0
10M
0.1 0.2 0.3
–75
Flyback Blanking Time
–30
0
30
60
90
120
150
180
210
–50
FEEDBACK CURRENT (mA)
JUNCTION TEMPERATURE ( C)
–25
0.4
0
–55 C
150 C
25 C
0.5 0.6 0.7 0.8 0.9 1.0
25
50
500
490
480
470
460
450
440
430
420
410
400
75 100 125
–50
Normal/Flyback Mode Threshold on
Feedback Pin
1170/1/2 G14
–25
1170/1/2 G17
FEEDBACK PIN VOLTAGE
FEEDBACK PIN CURRENT
(AT THRESHOLD)
0
150
(AT THRESHOLD)
TEMPERATURE ( C)
25
1000
900
800
700
600
500
400
300
200
100
23
22
21
20
19
18
17
16
15
50
0
–75
0
Switch “Off” Characteristics
Isolated Mode Flyback
Reference Voltage
V
SUPPLY
75
= 3V
10 20 30
–50
100 125 150
–25
SWITCH VOLTAGE (V)
TEMPERATURE ( C)
V
1170/1/2 G20
SUPPLY
= 15V
0
40
R
FB
R
25
R
FB
FB
50 60 70 80 90 100
= 500
–24
–22
–20
–18
–16
–14
–12
–10
– 8
– 6
– 4
= 10k
= 1k
50
V
SUPPLY
= 40V
75 100 125
V
= 55V
SUPPLY
1170/1/2 G18
1170/1/2 G15
150