Datasheet

LT3434
5
3434fb
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Switch Peak Current Limit
Soft-Start Threshold
vs FB Voltage
Oscillator Frequency
vs FB Voltage
TEMPERATURE (°C)
–50
3.0
3.5
4.0
PEAK SWITCH CURRENT (A)
4.5
5.0
5.5
6.0
–25 0 25 50
3434 G10
75 100 125
FB VOLTAGE (V)
0
0
CURRENT (µA)
10
20
30
0.2
0.4
0.6 0.8
3434 G11
1.0
40
50
5
15
25
35
45
1.2
SOFT-START
DEFEATED
T
J
= 25°C
FB VOLTAGE (V)
0
0
FREQUENCY (kHz)
50
100
150
0.2
0.4
0.6 0.8
3434 G12
1.0
200
250
1.2
T
J
= 25°C
Switch On Voltage (V
CESAT
)
LOAD CURRENT (A)
0.5
0
VOLTAGE (mV)
50
150
200
250
500
350
1.5
2.5
3434 G13
100
400
450
300
1.0 2.0 3.0
T
J
= 125°C
T
J
= 25°C
T
J
= –40°C
INPUT VOLTAGE (V)
0
0
SUPPLY CURRENT (µA)
50
100
10
20
30 40
3434 G20
50
150
25
75
125
60
V
OUT
= 3.3V
Supply Current vs Input Voltage
LOAD CURRENT (A)
0
3.0
INPUT VOLTAGE (V)
3.5
4.5
5.0
5.5
2.0
7.5
3434 G19
4.0
1.0
0.5
2.5
1.5 3.0
6.0
6.5
7.0
START-UP
V
OUT
= 5V
V
OUT
= 3.3V
RUNNING
START-UP
RUNNING
Minimum Input Voltage
Burst Mode Threshold vs Input
Voltage
Minimum On Time for Continuous
Mode Operation
Boost Current vs Load Current
INPUT VOLTAGE (V)
5
0
LOAD CURRENT (mA)
100
300
500
10
15
3434 G21
700
900
200
400
600
800
20
BURST MODE EXIT
(INCREASING LOAD)
BURST MODE ENTER
(DECREASING LOAD)
V
OUT
= 3.3V
L = 33µH
C
OUT
= 100µF
TEMPERATURE (°C)
–50
200
ON TIME (ns)
650
700
550
600
450
400
350
300
250
500
–25 0 25 50
3434 G22
75 100 125
LOAD CURRENT = 0.5A
LOAD CURRENT = 1A
LOAD CURRENT = 2A
SWITCH CURRENT (A)
0
0
BOOST CURRENT (mA)
10
20
30
40
60
0.5
1.0 1.5 2.0
3434 G23
2.5 3.0
50