Datasheet

LTC3545/LTC3545-1
17
35451fb
TYPICAL APPLICATIONS
Burst Mode Ripple
Overall Effi ciency vs
Channel 1 Load Current
Figure 4. LTC3545 Low Ripple Burst Mode Operation
CHANNEL 1 LOAD CURRENT (mA)
30
OVERALL EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.1 10 100 1000
3545 TA03
0
1
T
A
= 25°C
V
IN
= 3.6V
V
OUT
= 2.5V
f
OSC
= 2.25MHz
CHANNEL 2 = 1.2V, I
LOAD
= 400mA
CHANNEL 3 = 1.5V, I
LOAD
= 400mA
1µs/DIV
I
L3
250mA/DIV
V
OUT3
AC COUPLED
20mV/DIV
SW3
2V/DIV
3545 TA04
T
A
= 25°C
V
IN
= 3.6V
V
OUT
= 1.5V
I
LOAD
= 50mA
f
OSC
= 2.25MHz
3545 TA02
L1
1.5µH
R1
511k
C2
10µF
6.3V
C1
10µF
10V
SW1
PGOOD1
RUN2
PGOOD2
SW2
PGND
P
VIN
SW3
GNDA
V
IN
RUN1
V
FB1
V
FB2
V
FB3
RUN3
SYNC/MODE
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
LTC3545
GND
17
R3
191k
C6
20pF
R4
60.4k
R5
100k
R6
100k
R7
165k
R8
110k
R2
511k
V
IN
2.7V TO 5.5V
C5
4.7µF
E3
V
OUT1
E2
PGOOD2
E1
PGOOD1
2.5V AT 0.8A
E4
GND
C3
10µF
6.3V
E7
V
OUT2
1.2V AT 0.8A
E6
GND
C4
10µF
6.3V
E5
V
OUT3
1.5V AT 0.8A
E8
GND
L2
1.5µH
L3
1.5µH
C7
20pF
C8
20pF