Datasheet

LT3685
5
3685fb
BOOST DIODE CURRENT (A)
0
BOOST DIODE V
f
(V)
0.8
1.0
1.2
2.0
3685 G15
0.6
0.4
0
0.5 1.0 1.5
0.2
1.4
RUN/SS PIN VOLTAGE (V)
0
SWITCH CURRENT LIMIT (A)
3.5
1.5
3685 G13
2.0
1.0
0.5 1 2
0.5
0
4.0
3.0
2.5
1.5
2.5 3 3.5
FB PIN VOLTAGE (mV)
0
SWITCHING FREQUENCY (kHz)
800
1000
1200
600
3685 G11
600
400
200 400
800
500
100 300
700 900
200
0
R
T
= 29.4k
TEMPERATURE (˚C)
MINIMUM SWITCH ON TIME (ns)
80
100
120
3685
G
12
60
40
20
0
140
–50 25–25 0 50 75 100 15
0
125
RUN/SS PIN VOLTAGE (V)
0
RUN/SS PIN CURRENT (μA)
8
10
12
15 25
3685 G14
6
4
510
20 30 35
2
0
TEMPERATURE (°C)
FEEDBACK VOLTAGE (mV)
800
3685 G09
760
840
780
820
–50 25–25 0 50 75 100 150125
TEMPERATURE (°C)
FREQUENCY (MHz)
1.00
1.10
3685 G10
0.90
0.80
1.20
0.95
1.05
0.85
1.15
–50 25–25 0 50 75 100 150125
R
T
= 29.4k
Feedback Voltage
Switching Frequency Frequency Foldback
Minimum Switch On-Time
Soft-Start
RUN/SS Pin Current
Boost Diode
T
A
= 25°C unless otherwise noted.
FB PIN ERROR VOLTAGE (V)
–200
–50
V
C
PIN CURRENT (μA)
–20
0
20
020
0
50
3685 G16
–40
–100 100
40
10
–10
30
–30
Error Amp Output Current
TYPICAL PERFORMANCE CHARACTERISTICS