Datasheet

LT3957A
6
3957afa
INTV
CC
Line Regulation
INTV
CC
Dropout Voltage
vs Current, Temperature
INTV
CC
vs Temperature
INTV
CC
Minimum Output
Current Limit vs V
IN
INTV
CC
Load Regulation
TYPICAL PERFORMANCE CHARACTERISTICS
T
A
≈ T
J
= 25°C, unless otherwise noted.
TEMPERATURE (°C)
–50
5.0
INTV
CC
(V)
5.1
5.2
5.3
5.4
0
50
75
–25
25
100
125
3957A G13
1
0
10
20
40
60
10 100
90
80
30
50
70
T
J
= 125°C
INTV
CC
= 3V
V
IN
(V)
3957A G14
INTV
CC
CURRENT (mA)
INTV
CC
LOAD (mA)
0
4.8
5.0
5.1
5.2
5.3
30
50 60
4.9
10 20
40
3957A G15
INTV
CC
VOLTAGE (V)
V
IN
= 6V
V
IN
(V)
0
INTV
CC
VOLTAGE (V)
5.25
5.20
10 15
25
5
20
30 35 40
5.15
5.10
5.30
3957A G16
INTV
CC
LOAD (mA)
0
DROPOUT VOLTAGE (mV)
600
400
500
200
300
5 101520
100
0
700
3957A G17
125°C
25°C
0°C
–40°C
75°C
V
IN
= 5V
Internal Switch On-Resistance
vs Temperature
TEMPERATURE (°C)
–50
ON-RESISTANCE (mΩ)
35
40
45
30
25
–25 250 50 75 100 125
10
5
0
20
50
15
3957A G18
Internal Switch On-Resistance
vs INTV
CC
SEPIC Typical Start-Up
Waveforms
SEPIC FBX Frequency Foldback
Waveforms During Overcurrent
INTV
CC
(V)
3
ON-RESISTANCE (mΩ)
27.8
28.0
27.6
27.4
27.2
45 768
27.0
26.8
26.6
28.2
3957A G19
5ms/DIV
SEE TYPICAL APPLICATION: 5V TO 16V INPUT,
12V OUTPUT SEPIC CONVERTER
V
OUT
5V/DIV
I
L1A
+ I
L1B
2A/DIV
3957A G20
V
IN
= 12V
50µs/DIV
V
OUT
10V/DIV
V
SW
20V/DIV
I
L1A
+ I
L1B
5A/DIV
3957A G21
V
IN
= 12V
SEE TYPICAL APPLICATION: 5V TO 16V INPUT,
12V OUTPUT SEPIC CONVERTER