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