Datasheet

LTC3728
7
3728fg
TYPICAL PERFORMANCE CHARACTERISTICS
Soft-Start Up (Figure 13) Load Step (Figure 13) Load Step (Figure 13)
Input Source/Capacitor
Instantaneous Current (Figure 13) Burst Mode Operation (Figure 13)
Constant-Frequency (Burst
Inhibit) Operation (Figure 13)
Current Sense Pin Input Current
vs Temperature
EXTV
CC
Switch Resistance
vs Temperature
Oscillator Frequency
vs Temperature
TEMPERATURE (°C)
–50 –25
25
CURRENT SENSE INPUT CURRENT (μA)
29
35
0
50
75
3728 G26
27
33
31
25
100
125
V
OUT
= 5V
TEMPERATURE (°C)
–50 –25
0
EXTV
CC
SWITCH RESISTANCE (Ω)
4
10
0
50
75
3728 G27
2
8
6
25
100
125
TEMPERATURE (°C)
–50
400
500
700
25 75
3728 G28
300
200
–25 0
50 100 125
100
0
600
FREQUENCY (kHz)
V
PLLFLTR
= 5V
V
PLLFLTR
= 1.2V
V
PLLFLTR
= 0V
V
IN
= 15V
V
OUT
= 5V
5ms/DIV
3728 G19
V
RUN/SS
5V/DIV
V
OUT
5V/DIV
I
L
2A/DIV
V
IN
= 15V
V
OUT
= 5V
V
PLLFLTR
= 0V
LOAD STEP = 0A to 3A
Burst Mode OPERATION
20µs/DIV
3728 G20
V
OUT
200mV/DIV
I
L
2A/DIV
V
IN
= 15V
V
OUT
= 5V
V
PLLFLTR
= 0V
LOAD STEP = 0A to 3A
CONTINUOUS OPERATION
20µs/DIV
3728 G21
V
OUT
200mV/DIV
I
L
2A/DIV
V
IN
= 15V
V
OUT
= 5V
V
PLLFLTR
= 0V
I
OUT
= I
OUT3.3A
= 2A
1µs/DIV
3728 G22
V
SW1
10V/DIV
V
SW2
10V/DIV
I
IN
2A/DIV
V
IN
200mV/DIV
V
IN
= 15V
V
OUT
= 5V
V
PLLFLTR
= 0V
V
FCB
= OPEN
I
OUT
= 20mA
10µs/DIV
3728 G23
V
OUT
20mV/DIV
I
L
0.5A/DIV
V
IN
= 15V
V
OUT
= 5V
V
PLLFLTR
= 0V
V
FCB
= 5V
I
OUT
= 20mA
2µs/DIV
3728 G24
V
OUT
20mV/DIV
I
L
0.5A/DIV