Datasheet

LT3685
4
3685fb
SWITCH CURRENT (mA)
0
BOOST PIN CURRENT (mA)
10
30
40
50
80
3685 G08
20
60
70
0 1500500 1000 2000 2500
LOAD CURRENT (A)
0
50
EFFICIENCY (%)
100
0.2 0.4 0.6 0.8 1.2 1.4 1.6 1.8 2.01.0
3685 G01
60
90
80
70
V
IN
= 24V
V
IN
= 34V
V
IN
= 12V
L: NEC PLC-0745-5R6
f: 800kHz
V
OUT
= 5V
0 0.2 0.4 0.6 0.8 1.2 1.4 1.6 1.8 2.01.0
LOAD CURRENT (A)
50
EFFICIENCY (%)
90
3685 G02
60
65
55
85
80
70
75
V
IN
= 12V
V
IN
= 7V
L: NEC PLC-0745-5R6
f: 800kHz
V
IN
= 24V
V
IN
= 34V
V
OUT
= 3.3V
INPUT VOLTAGE (V)
5
LOAD CURRENT (A)
15
3685 G03
2.5
10 20
1.5
1.0
4.0
3.5
3.0
2.0
25 30
TYPICAL
MINIMUM
V
OUT
= 3.3V
L = 4.7μH
f = 800 kHz
SWITCH CURRENT (mA)
0
400
500
700
1500
3685 G07
300
200
500 1000 2000 2500
100
0
600
VOLTAGE DROP (mV)
Effi ciency
Effi ciency
Boost Pin Current
Switch Voltage Drop
Maximum Load Current
T
A
= 25°C unless otherwise noted.
DUTY CYCLE (%)
0
SWITCH CURRENT LIMIT(A)
40
3685 G05
2.5
20 60
1.5
1.0
4.0
3.5
3.0
2.0
80 100
INPUT VOLTAGE (V)
5
LOAD CURRENT (A)
15
3685 G04
2.5
10 20
1.5
1.0
3.5
3.0
2.0
25 30
TYPICAL
MINIMUM
V
OUT
= 5V
L = 4.7μH
f = 800kHz
TEMPERATURE (°C)
SWITCH CURRENT LIMIT (A)
2.0
2.5
3.5
3.0
3685 G06
1.5
1.0
0
0.5
4.5
4.0
DUTY CYCLE = 10 %
DUTY CYCLE = 90 %
–50 25–25 0 50 75 100 150125
Switch Current Limit Switch Current Limit
Maximum Load Current
TYPICAL PERFORMANCE CHARACTERISTICS