Datasheet

LT3640
6
3640f
Typical perForMance characTerisTics
FB2 Voltage vs SS2
Switching Frequency
vs Temperature
HV Channel Current Limit
vs Duty Cycle
V
OUT1
Minimum Load to Run at
Full Frequency (V
OUT1
= 3.3V)
HV Channel Switching Frequency
(V
OUT1
= 3.3V)
LV Channel Switching Frequency
(V
OUT2
= 1.8V)
LV Channel Peak Current Limit
vs Duty Cycle
LV Channel Switch Voltage
Drop vs Current (V
IN2
= 3.3V)
T
A
= 25°C, unless otherwise noted.
SS2 VOLTAGE (mV)
FB2 VOLTAGE (mV)
3640 G10
0
200
400
600
700
100
300
500
0
200
400 6000 800 1000
TEMPERATURE (°C)
–50
SWITCHING FREQUENCY (MHz)
50
0
100 150
3640 G11
0.48
0.50
0.52
0.49
0.51
R
T
= 182k
DUTY CYCLE (%)
SW1 PEAK CURRENT LIMIT (A)
3640 G12
0
20
40 60 80 100
0.0
1.0
2.0
2.5
0.5
1.5
DUTY CYCLE (%)
SW2 PEAK CURRENT LIMIT (A)
3640 G13
0
20
40 60 80 100
0.0
1.0
2.0
0.5
1.5
SW2 CURRENT (A)
0
SW2 VOLTAGE DROP (mV)
300
350
400
250
200
0.5 1 1.5
50
0
150
450
100
3640 G14
PMOS
NMOS
V
IN
VOLTAGE (V)
0
V
OUT1
CURRENT (A)
0.30
0.35
0.40
0.25
0.20
5 1510 20 25 30
0.05
0
0.15
0.45
0.10
3640 G15
2MHz
2.5MHz
V
OUT1
CURRENT (A)
SWITCHING FREQUENCY (MHz)
3640 G16
0
1.0
2.0
2.5
0.5
1.5
0
0.2
0.4 0.6 0.8
1.0 1.2
V
IN
= 12V
V
IN
= 24V
V
IN
= 16V
R
T
= 32.4k
V
OUT2
CURRENT (A)
SWITCHING FREQUENCY (MHz)
3640 G17
0
1.0
2.0
2.5
0.5
1.5
0
0.2
0.4 0.6 0.8
1.0
V
IN2
= 3.3V
V
IN2
= 5V