Datasheet

LTC3561
13
3561f
I
LOAD
(mA)
1
40
EFFICIENCY (%)
80
90
100
10 100 1000
3561 TA03
70
60
50
0
40
50
60
30
20
10
V
IN
= 3.3V
V
OUT
= 1.2V
EFFICIENCY
V
OUT
RIPPLE
V
OUT
RIPPLE (mV)
TYPICAL APPLICATIO S
U
Figure 6. General Purpose Buck Regulator Using Ceramic Capacitors
SV
IN
LTC3561
SW
PV
IN
V
FB
I
TH
SHDN/R
T
L1
2.2µH
V
IN
2.63V TO
5.5V
V
OUT
1.8V/2.5V/3.3V
AT 1A
R4
324k
R1A
280k
R3
13k
3561 F07a
C3
1000pF
C4 22pF
R2 887K
C2
22µF
R1B
412k
R1C
698k
C1
10µF
PGNDSGND
NOTE: IN DROPOUT, THE OUTPUT TRACKS THE INPUT VOLTAGE
C1, C2: TAIYO YUDEN JMK325BJ226MM
L1: TOKO A914BYW-2R2M (D52LC SERIES)
3.3V 2.5V 1.8V
Small Footprint Buck
LOAD CURRENT (mA)
1
0
EFFICIENCY (%)
30
20
10
60
50
40
100
90
80
70
10 100 1000
3561 F07b
V
IN
= 3.3V
V
OUT
= 2.5V
f
O
= 1MHz
Efficiency vs Load Current
Efficiency and V
OUT
Ripple
PV
IN
LTC3561
PGND
SW
SV
IN
SGND
V
FB
I
TH
SHDN/R
T
L1
2.2µH
D1
1.2V
AT 1.0A
V
IN
2.63V
TO 5.5V
R4
324k
C4
22pF
R2
100k
R1
200k
R3
10k
3561 TA02
C3
470pF
C1: AVX 06034D106M
C2: AVX 08054D226M
L1: SUMIDA CDRH2D18/HP-2R2
C2
22µF
C1
10µF