LTC3642
TYPICAL PERFORMANCE CHARACTERISTICS
Switch On-Resistance vs
Input Voltage
4.5
4.0
SWITCH ON-RESISTANCE (Ω)
SWITCH ON-RESISTANCE (Ω)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0
10
30
20
V
IN
VOLTAGE (V)
40
50
3642 G10
Switch On-Resistance vs
Temperature
5
V
IN
= 10V
SWITCH LEAKAGE CURRENT (μA)
0.6
0.5
0.4
Switch Leakage Current vs
Temperature
V
IN
= 45V
4
TOP
3
BOTTOM
TOP
SW = 0V
0.3
0.2
SW = 45V
0.1
0
–40
BOTTOM
2
1
0
–40
–10
50
80
20
TEMPERATURE (°C)
110
3642 G11
–10
20
50
80
TEMPERATURE (°C)
110
3642 G12
Efficiency vs Input Voltage
95
90
EFFICIENCY (%)
85
I
LOAD
= 10mA
80
I
LOAD
= 1mA
75
70
65
10
15
20
25
30
35
INPUT VOLTAGE (V)
40
45
RUN COMPARATOR THRESHOLD (V)
FIGURE 10 CIRCUIT
I
SET
OPEN
I
LOAD
= 50mA
1.30
1.25
1.20
1.15
Run Comparator Thresholds vs
Temperature
1.20
INTERNAL SOFT-START TIME (ms)
110
3642 G14
Internal Soft-Start Time vs
Temperature
RISING
1.15
1.10
1.05
1.00
0.95
0.90
–40
FALLING
1.10
1.05
1.00
–40
–10
20
50
80
TEMPERATURE (°C)
–10
20
50
80
TEMPERATURE (°C)
110
3642 G15
3642 G13
Soft-Start Waveforms
OUTPUT
VOLTAGE
1V/DIV
OUTPUT
VOLTAGE
50mV/DIV
SWITCH
VOLTAGE
5V/DIV
INDUCTOR
CURRENT
50mA/DIV
V
IN
= 10V
500μs/DIV
C
SS
= 0.047μF
I
SET
OPEN
FIGURE 10 CIRCUIT
4632 G16
Operating Waveforms
OUTPUT
VOLTAGE
25mV/DIV
Load Step Transient Response
INDUCTOR
CURRENT
50mA/DIV
LOAD
CURRENT
25mA/DIV
V
IN
= 10V
10μs/DIV
I
SET
OPEN
FIGURE 10 CIRCUIT
4632 G17
V
IN
= 10V
1ms/DIV
I
SET
OPEN
FIGURE 10 CIRCUIT
4632 G18
3642f
5
LINER [ LINEAR TECHNOLOGY ]
