lt3990 Linear Technology Corporation, lt3990 Datasheet - Page 6

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

LT3990
Typical perFormance characTerisTics

100mA/DIV
100mV/DIV
1.2
1.0
0.8
0.6
0.4
0.2
92
91
90
89
88
V
0
OUT
–50
0
I
Boost Diode Forward Voltage
Power Good Threshold
L
Transient Load Response; Load
Current is Stepped from 100mA
to 200mA
FRONT PAGE APPLICATION
V
V
IN
OUT
–25
= 12V
= 5V
BOOST DIODE CURRENT (mA)
50
0
TEMPERATURE (°C)
25
100µs/DIV
100
50
75
150
100 125 150
–50°C
25°C
125°C
150°C
3990 G19
3990 G22
3990 G25
200
100mA/DIV
5mV/DIV
1.185
1.260
1.235
1.210
1.160
5V/DIV
1.0
0.8
0.6
0.4
0.2
V
V
0
OUT
SW
–50
I
0
EN/UVLO Threshold
L
Catch Diode Forward Voltage
Switching Waveforms,
Burst Mode Operation
FRONT PAGE APPLICATION
V
V
I
LOAD
IN
OUT
–25
= 12V
= 5V
= 10mA
CATCH DIODE CURRENT (mA)
100
0
TEMPERATURE (°C)
25
200
2µs/DIV
50
75
100 125 150
300
–50°C
25°C
125°C
150°C
T
A
3990 G23
3990 G20
= 25°C, unless otherwise noted.
3990 G26
400
100mV/DIV
100mA/DIV
200mA/DIV
5mV/DIV
V
5V/DIV
OUT
20
16
V
12
V
I
8
4
0
OUT
L
–50
SW
I
FRONT PAGE APPLICATION
V
V
Catch Diode Leakage
Transient Load Response; Load
Current is Stepped from 10mA
(Burst Mode Operation) to 110mA
L
V
IN
OUT
Switching Waveforms, Full
Frequency Continuous Operation
FRONT PAGE APPLICATION
V
V
I
R
LOAD
= 12V
IN
OUT
–25
= 12V
= 5V
= 12V
= 5V
= 350mA
0
TEMPERATURE (°C)
25
100µs/DIV
1µs/DIV
50
75
100 125
3990 G24
3990 G21
3990p
3990 G27
150