LT1977 Linear Technology, LT1977 Datasheet - Page 4

• Manufacturer Part Number: LT1977
• Description: Step-Down Switching Regulator
• Manufacturer: Linear Technology

LT1977
TYPICAL PERFOR A CE CHARACTERISTICS
4
1.30
1.29
1.28
1.27
1.26
1.25
1.24
1.23
1.22
1.21
1.20
200
180
160
140
120
100
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
80
60
40
20
0
0
–50
–50
0
FB Voltage
SHDN Pin Current
Bias Sleep Current
T
J
= 25°C
–25
–25
10
0
0
TEMPERATURE (°C)
TEMPERATURE (°C)
SHDN VOLTAGE (V)
20
25
25
30
50
50
40
75
75
W
100
50
100
1977 G01
1977 G04
1977 G07
U
125
125
60
1.20
1.18
1.16
1.14
1.12
1.10
1.08
1.06
1.04
1.02
1.00
550
540
530
520
510
500
490
480
470
460
450
25
20
15
10
5
0
–50
–50
–50
Oscillator Frequency
Shutdown Supply Current
PGFB Threshold
–25
–25
–25
V
IN
0
0
0
TEMPERATURE (°C)
= 42V
TEMPERATURE (°C)
TEMPERATURE (°C)
25
25
25
V
50
50
50
V
IN
IN
= 12V
= 60V
75
75
75
100
100
100
1977 G02
1977 G05
1977 G08
125
125
125
1.10
1.40
1.35
1.30
1.25
1.20
0.15
1.05
1.00
250
200
150
100
200
180
160
140
120
100
50
80
60
40
20
0
0
–50
–50
–50
PG Sink Current
SHDN Threshold
Sleep Mode Supply Current
–25
–25
–25
0
0
0
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
V
V
BIAS
BIAS
25
25
25
= 0V
= 5V
50
50
50
75
75
75
100
100
100
1977 G09
1977 G03
1977 G06
1977f
125
125
125