Datasheet

LT3580
4
3580fg
TYPICAL PERFORMANCE CHARACTERISTICS
Switch Current Limit at 1MHz Switch Saturation Voltage
Switch Current Limit at Minimum
Duty Cycle
Switch Current Limit at Minimum
Duty Cycle
Positive Feedback Voltage
Switching Waveforms for
Figure 14 Circuit
Oscillator Frequency
Oscillator Frequency During
Soft-Start
Internal UVLO
T
A
= 25°C unless otherwise specified
DUTY CYCLE (%)
10
0
SWITCH CURRENT LIMIT (A)
0.5
1.0
1.5
2.0
30 50
70
90
3580 G01
2.5
20 40
60
80
SWITCH CURRENT (A)
0
SATURATION VOLTAGE (mV)
200
250
300
2
3580 G02
150
100
0
0.5
1
1.5
50
400
350
SS VOLTAGE (mV)
0
0
SWITCH CURRENT (A)
0.5
1.0
1.5
2.0
200
400 600 800
3580 G03
1000 1200
2.5
TEMPERATURE (°C)
–50
0
SWITCH CURRENT LIMIT (A)
0.5
1.0
1.5
2.0
2.5
3.0
0 50 100
3580 G04
TEMPERATURE (°C)
–50 –25
1.19
FB VOLTAGE (V)
1.21
1.24
0
50
75
3580 G05
1.20
1.23
1.22
25
100
125
V
OUT
50mV/DIV
AC COUPLED
V
SW
10V/DIV
I
L
0.5A/DIV
200ns/DIV
3580 G06
TEMPERATURE (°C)
–50
FREQUENCY (MHz)
1.9
2.1
2.3
3580 G07
1.7
1.5
1.1
0
50
100
1.3
2.7
R
T
= 35.7k
2.5
R
T
= 75k
FB VOLTAGE (V)
0
0
NORMALIZED OSCILLATOR FREQUENCY (F/F
NOM
)
1/4
1/2
T
A
= –35°C
T
A
= 25°C
T
A
= 100°C
1/3
1
0.2 0.4
INVERTING
CONFIGURATIONS
BOOSTING
CONFIGURATIONS
0.6 0.8
3580 G08
1.0 1.2
TEMPERATURE (°C)
–50
2.20
V
IN
VOLTAGE (V)
2.22
2.26
2.28
2.30
2.40
2.34
0
50
3580 G09
2.24
2.36
2.38
2.32
100
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