LT3681
TYPICAL PERFOR A CE CHARACTERISTICS
T
A
= 25°C unless otherwise noted.
Switch Voltage Drop
700
600
BOOST PIN CURRENT (mA)
VOLTAGE DROP (mV)
500
400
300
200
100
0
0
500
1000 1500 2000 2500 3000 3500
SWITCH CURRENT (mA)
3681 G10
FEEDBACK VOLTAGE (V)
Switching Frequency
1.20
1.15
1.10
FREQUENCY (MHz)
1.05
1.00
0.95
0.90
0.85
0.80
–50
–25
0
25
50
75
TEMPERATURE (°C)
100
125
SWITCHING FREQUENCY (kHz)
R
T
= 45.3kΩ
1200
1000
800
600
400
200
0
0
200
400 600 800 1000 1200 1400
FB PIN VOLTAGE (mV)
3681 G14
MINIMUM SWITCH ON TIME (ns)
Soft Start
4.0
3.5
SWITCH CURRENT LIMIT (A)
3.0
2.5
2.0
1.5
1.0
0.5
0
0
0.5
2
2.5
1.5
RUN/SS PIN VOLTAGE (V)
1
3
3.5
3681 G16
RUN/SS PIN CURRENT (µA)
8
6
4
2
BOOST DIODE V
f
(V)
U W
Boost Pin Current
90
80
70
60
50
40
30
20
10
0
0
500 1000 1500 2000 2500 3000 3500
SWITCH CURRENT (mA)
3681 G11
Feedback Voltage
1.290
1.285
1.280
1.275
1.270
1.265
1.260
1.255
1.250
–50
–25
0
25
50
75
TEMPERATURE (°C)
100
125
4681 G12
Frequency Foldback
140
R
T
= 45.3kΩ
120
100
80
60
40
20
Minimum Switch On-Time
0
–50
–25
25
0
50
75
TEMPERATURE (˚C)
100
125
4681 G13
3681 G15
RUN/SS Pin Current
12
10
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
5
20
30
15
25
10
RUN/SS PIN VOLTAGE (V)
35
3681 G17
Boost Diode
0
0
1.0
0.5
1.5
BOOST DIODE CURRENT (A)
2.0
3681 G18
3681f
5
LINER [ LINEAR TECHNOLOGY ]
