Datasheet

LT3973/LT3973-3.3/LT3973-5
6
3973fa
Typical perFormance characTerisTics
Maximum Load Current Maximum Load CurrentMaximum Load Current
Load Regulation
T
A
= 25°C, unless otherwise noted.
Switch Current Limit Switch Current Limit
Switching Frequency
Minimum Switch On-Time
Switch V
CESAT
(I
SW
= 500mA)
vs Temperature
INPUT VOLTAGE (V)
5
0
LOAD CURRENT (A)
0.2
0.4
1.6
1.4
1.2
1.0
0.8
0.6
1510 20 25 30 35 40
3973 G10
45
FRONT PAGE APPLICATION
V
OUT
= 3.3V
TYPICAL
MINIMUM
INPUT VOLTAGE (V)
5 10
0
LOAD CURRENT (A)
0.3
0.6
1.5
1.2
0.9
15 20 30 4025 35
3973 G11
45
FRONT PAGE APPLICATION
V
OUT
= 5V
TYPICAL
MINIMUM
TEMPERATURE (°C)
–50
LOAD CURRENT (A)
0.8
1.0
1.2
1.4
25 75
3973 G12
0.6
0.4
0.2
0
–25 0
50
100 125 150
FRONT PAGE APPLICATION
V
IN
= 12V
V
OUT
= 5V
LIMITED BY MAXIMUM
JUNCTION TEMPERATURE;
θ
JA
= 45°C/W
LIMITED BY CURRENT LIMIT
H-GRADE
LOAD CURRENT (mA)
0
LOAD REGULATION (%)
0.15
300
3973 G13
0
–0.10
100 200 400
–0.15
–0.20
0.25
0.20
0.10
0.05
–0.05
500 600 700
FRONT PAGE APPLICATION
REFERENCED FROM V
OUT
AT 100mA LOAD
DUTY CYCLE (%)
0
0.8
SWITCH CURRENT LIMIT (A)
1.0
1.2
1.4
1.6
1.8
2.0
20 40 60 80
3973 G14
100
SWITCH PEAK
CURRENT LIMIT
CATCH DIODE VALLEY CURRENT LIMIT
TEMPERATURE (°C)
–50
0.8
SWITCH CURRENT LIMIT (A)
1.0
1.2
1.4
1.6
0 50
100
150
3973 G15
1.8
2.0
–25 25
75
125
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
3973 G16
100 125 150
2.0
0.2
0.6
1.0
1.4
2.2
1.8
TEMPERATURE (°C)
–50
0
SWITCH ON-TIME (ns)
25
75
150
0
50
75
3973 G17
50
125
100
–25 25
100
125
150
LOAD CURRENT = 375mA
TEMPERATURE (°C)
–50
200
SWITCH V
CESAT
(mV)
250
300
350
–25 0 25 50
3973 G18
75 100 125 150