Datasheet

LTC3621/LTC3621-2
5
3621fb
For more information www.linear.com/LTC3621
Typical perForMance characTerisTics
Burst Mode Operation Pulse-Skipping Mode Operation Load Step
Soft-Start Operation Efficiency vs Input Voltage
Oscillator Frequency
vs Temperature
Efficiency vs Load Current
(Burst Mode Operation)
V
IN
Supply Current
vs Input Voltage
Efficiency vs Load at Dropout
Operation
T
J
= 25°C, unless otherwise noted.
INPUT VOLTAGE (V)
0
V
IN
SUPPLY CURRENT (µA)
3
4
5
16
3621 G02
2
1
0
2 4 6
8 10
12 14 18
20
SLEEP
SD
3621 G04
SW
5V/DIV
4µs/DIV
V
OUT
AC-COUPLED
50mV/DIV
I
L
500mA/DIV
V
IN
= 12V
V
OUT
= 3.3V
Burst Mode OPERATION
I
OUT
= 50mA
L = 2.2µH
3621 G07
RUN
5V/DIV
PGOOD
2V/DIV
V
OUT
1V/DIV
I
L
0.5A/DIV
400µs/DIV
3621 G05
SW
5V/DIV
V
OUT
AC-COUPLED
50mV/DIV
I
L
500mA/DIV
V
IN
= 12V
V
OUT
= 3.3V
PULSE SKIP MODE
I
OUT
= 10mA
L = 2.2µH
4µs/DIV
3621 G06
I
LOAD
500mA/DIV
V
OUT
100mV/DIV
I
L
500mA/DIV
V
IN
= 12V
V
OUT
= 3.3V
I
LOAD
= 0.05A
40µs/DIV
LOAD CURRENT (A)
EFFICIENCY (%)
3621 G01
100
90
80
70
60
50
40
30
20
10
0
0.001 0.1
1
0.01
V
IN
= 12V
FREQUENCY = 2.25MHz
V
OUT
= 2.5V
V
OUT
= 3.3V
V
OUT
= 5V
LOAD CURRENT (A)
EFFICIENCY (%)
3621 G03
100
90
80
70
60
50
40
30
20
10
0
0.0001 0.001 0.1
1
0.01
V
IN
= 5V
FREQUENCY = 2.25MHz
FORCED
CONTINUOUS
MODE
Burst Mode
OPERATION
TEMPERATURE (°C)
–50
OSCILLATOR FREQUENCY (MHz)
2.30
2.35
2.45
2.50
2.40
25 75
3621 G09
2.25
2.20
–25 0
50 100 125
2.15
2.05
2.00
2.10
INPUT VOLTAGE (V)
0
70
EFFICIENCY (%)
5
96
3621 G08
10 15
20
94
92
90
88
86
84
82
80
78
76
74
72
V
OUT
= 2.5V
I
LOAD
= 10mA
I
LOAD
= 1A