Datasheet

LT3581
5
3581fa
For more information www.linear.com/LT3581
Typical perForMance characTerisTics
Switch Fault Current Limit vs
Temperature
Positive Feedback Voltage
vs Temperature
CLKOUT Duty Cycle
vs Temperature
Oscillator Frequency Frequency Foldback Gate Current vs Gate Voltage
Switch Fault Current Limit vs
Duty Cycle
Switch Saturation Voltage with
SW1 and SW2 Tied Together
Current Sharing Between SW1 and
SW2 When Tied Together
T
A
= 25°C, unless otherwise noted.
DUTY CYCLE (%)
20
0
SW1 + SW2 FAULT CURRENT LIMIT (A)
1
2
3
4
30 50
70
80
3581 G01
5
6
40
60
SW1 + SW2 CURRENT (A)
0
SATURATION VOLTAGE (mV)
200
250
300
5
4
3581 G02
150
100
0
321
50
450
400
350
SW1 + SW2 CURRENT (A)
0
CURRENT SHARING = SW2/SW1 (%)
50
60
70
5
4
3581 G03
40
30
0
321
10
20
100
90
80
TEMPERATURE (°C)
–50 –25
0
SW1 + SW2 FAULT CURRENT LIMIT (A)
1
2
3
4
0 50 125
150
3581 G04
5
6
25 75 100
–50 –25 0 50 125
150
25 75 100
TEMPERATURE (°C)
1.2100
POSITIVE FB VOLTAGE (V)
1.2125
1.2200
3581 G05
1.2175
1.2150
TEMPERATURE (°C)
–75 –50 –25
10
CLKOUT DC (%)
20
30
40
50
0 50 125
150
3581 G06
60
80
70
25 75 100
–50 –25 0 50 125
150
25 75 100
TEMPERATURE (°C)
0
FREQUENCY (kHz)
3200
3581 G07
2800
2400
2000
1600
1200
800
400
R
T
= 34k
R
T
= 432k
FB VOLTAGE (V)
0
0
SWITCHING FREQUENCY RATIO (f
SW
/f
OSC
)
1/4
1/5
1/6
1/2
1/3
1
0.2 0.4 0.6 0.8
3581 G08
1.0
1.2
BOOSTING
CONFIGURATIONS
INVERTING
CONFIGURATIONS
0 60
80
20 40
GATE VOLTAGE (V)
0
GATE CURRENT (µA)
1000
3581 G09
900
800
700
600
500
400
200
100
300
125°C
–40°C
25°C