LT3681_15 Datasheet, PDF (4/24 Pages) Linear Technology – 36V, 2A, 2.8MHz Step-Down Switching Regulator with Integrated Power Schottky Diode

LT3681
TYPICAL PERFOR A CE CHARACTERISTICS T_A = 25°C unless otherwise noted.
Efficiency (V_OUT = 5.0V)
100
90
V_IN = 12V
80
V_IN = 24V
70
60
50
40
30
20
10
0
0.0001
L: NEC PLC-0745-4R7
f: 800kHz
0.001 0.01 0.1
1
10
LOAD CURRENT (A)
3681 G01
No Load Supply Current
90
80
70
60
50
40
30
20
10
FRONT PAGE APPLICATION
0
0 5 10 15 20 25
INPUT VOLTAGE (V)
30 35
3681 G04
Maximum Load Current
4.0
3.5
3.0
2.5
2.0
1.5
1.0
5
V_OUT = 5.0V
L = 4.7µH
f = 800 kHz
10
15
20
25
30
INPUT VOLTAGE (V)
3681 G07
4
Efficiency (V_OUT = 3.3V)
100
90
80
V_IN = 7V
70
60
50
V_IN = 24V
V_IN = 12V
40
30
20
10
0
0.0001
L: NEC PLC-0745-4R7
f: 800kHz
0.001 0.01 0.1
1
10
LOAD CURRENT (A)
3681 G02
No Load Supply Current vs
Temperature
100
V_IN = 12V
V_OUT = 3.3V
90
80
INCREASED SUPPLY
CURRENT DUE TO CATCH
DIODE LEAKAGE AT
70
HIGH TEMPERATURE
60
50
40
–40 –20
0 20 40 60
TEMPERATURE (°C)
80
3681 G05
Switch Current Limit
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0
20
40
60
80
100
DUTY CYCLE (%)
3681 G08
Efficiency vs Switching Frequency
90
85
V_IN = 12V
80
V_IN = 24V
75
70
65
60
V_OUT = 3.3V
55
L = 10µH
LOAD = 1A
50
0 0.5 1 1.5 2 2.5 3
SWITCHING FREQUENCY (MHz)
3681 G03
Maximum Load Current
4.0
3.5
3.0
2.5
2.0
1.5
1.0
5
V_OUT = 3.3V
L = 4.7µH
f = 800 kHz
10
15
20
25
30
INPUT VOLTAGE (V)
3681 G06
Switch Current Limit
4.5
4.0
DUTY CYCLE = 10 %
3.0
2.5
DUTY CYCLE = 90 %
2.0
1.5
1.0
0.5
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3681 G09
3681f