LT3980
4
3980fa
For more information www.linear.com/LT3980
INPUT VOLTAGE (V)
0
3980 G04
50
30
10 20
10
130
110
90
70
30 40 50 60
V
OUT
= 3.3V
DUTY CYCLE (%)
0
SWITCH CURRENT LIMIT (A)
40
3980 G08
3.5
20 60
2.5
2.0
4.5
4.0
3.0
80 100
TYPICAL
MINIMUM
TEMPERATURE (°C)
–50
SUPPLY CURRENT (µA)
350
25
3980 G05
200
100
–25 0 50
50
0
400
300
250
150
75 100 150125
V
IN
= 12V
V
OUT
= 3.3V
CATCH DIODE: DIODES, INC. PDS360
INCREASED SUPPLY
CURRENT DUE TO CATCH
DIODE LEAKAGE AT
HIGH TEMPERATURE
I
LOAD
(A)
0 0.5
EFFICIENCY (%)
1
2
3980 G02
1.5
V
IN
= 12V
V
IN
= 48V
f = 400kHz
D = DIODES, INC. SBR3U100LP
V
IN
= 24V
85
70
60
55
50
95
90
80
75
65
INPUT VOLTAGE (V)
3980 G07
2.0
3.0
2.5
TYPICAL
MINIMUM
5 10 20 30 40 5015 25 35 45 6055
INPUT VOLTAGE (V)
LOAD CURRENT (A)
3980 G06
2.0
3.0
2.5
TYPICAL
MINIMUM
5 10 20 30 40 5015 25 35 45 6055
TEMPERATURE (°C)
SWITCH CURRENT LIMIT (A)
4.0
4.5
5.5
5.0
3980 G09
3.5
3.0
2.0
2.5
6.5
6.0
DUTY CYCLE = 10%
–50 25–25 0 50 75 100 150125
Efficiency, V
OUT
= 5V
No-Load Supply Current
Maximum Load Current,
V
OUT
= 3.3V
Switch Current Limit
Switch Current Limit
Maximum Load Current,
V
OUT
= 5V
No-Load Supply Current
T
A
= 25°C unless otherwise noted.
SWITCHING FREQUENCY (MHz)
0.20
POWER LOSS (W)
84
86
1.60
82
80
0.60 1.00
0.40
0.80 1.20
1.80
1.40 2.00
74
72
78
76
3.0
3.5
2.5
2.0
0.5
0
1.5
1.0
3980 G03
V
IN
= 12V
V
OUT
= 5V
I
OUT
= 2A
Typical perFormance characTerisTics
Efficiency, V
OUT
= 3.3V
Efficiency vs Switching Frequency
I
LOAD
(A)
0 0.5
EFFICIENCY (%)
1
2
3980 G01
1.5
V
IN
= 12V
V
IN
= 48V
f = 400kHz
D = DIODES, INC. SBR3U100LP
V
IN
= 24V
85
70
60
55
50
80
75
65
