lt3990 Linear Technology Corporation, lt3990 Datasheet - Page 5

• Manufacturer Part Number: lt3990
• Description: 60v, 350ma Step-down Regulator With 2.5?a Quiescent Current And Integrated Diodes
• Manufacturer: Linear Technology Corporation

Typical perFormance characTerisTics
800
700
600
500
400
300
200
150
250
225
200
175
125
100
75
50
25
21
18
15
12
0
9
6
3
0
–50
0
0
Switch Current Limit
Minimum
Switch On-Time/Switch Off-Time
BOOST Pin Current
LOAD CURRENT = 175mA
CATCH DIODE VALLEY CURRENT LIMIT
–25
20
100
0
SWITCH CURRENT (mA)
MINIMUM OFF-TIME
TEMPERATURE (°C)
DUTY CYCLE (%)
MINIMUM ON-TIME
25
200
40
CURRENT LIMIT
SWITCH PEAK
50
300
60
75
100 125 150
400
80
3990 G10
3990 G13
3990 G16
100
500
600
300
250
200
150
900
800
700
400
300
500
5.0
4.5
4.0
3.5
3.0
2.5
–50
–50
0
Switch Current Limit
Switch V
vs Temperature
Minimum Input Voltage,
V
FRONT PAGE APPLICATION
V
OUT
OUT
TO START
CATCH DIODE VALLEY CURRENT LIMIT
–25
–25
50
= 3.3V
= 3.3V
SWITCH PEAK CURRENT LIMIT
0
0
100
CESAT
LOAD CURRENT (mA)
TEMPERATURE ( C)
TEMPERATURE (°C)
25
25
150
(I
TO RUN
SW
50
50
200
= 200mA)
75
75
250
100
100 125 150
300
125
T
A
3990 G14
3990 G17
3990 G11
= 25°C, unless otherwise noted.
350
150
600
500
400
300
200
100
2.4
2.2
2.0
1.8
0.4
0.2
6.5
6.0
5.5
5.0
4.5
4.0
1.6
1.4
1.2
1.0
0.8
0.6
0
0
–50
0
0
Switching Frequency
Switch V
Minimum Input Voltage,
V
FRONT PAGE APPLICATION
f = 600kHz
OUT
–25
50
100
= 5V
TO START
SWITCH CURRENT (mA)
0
100
CESAT
LOAD CURRENT (mA)
TEMPERATURE (°C)
TO RUN
25
200
150
50
200
300
LT3990
75
250
100 125 150
400
300
3990 G12
3990 G15
3990 G18

3990p
350
500