Datasheet

LTC3122
19
3122fa
For more information www.linear.com/LTC3122
Typical applicaTions
Single Li-Cell to 6V, 5W, 3MHz Synchronous Boost Converter for RF Transmitter
2 AA Cell to 12V Synchronous Boost Converter, 180mA
3122 TA02a
V
IN
SD
PWM/SYNC
RT
V
CC
V
OUT
CAP
FB
V
C
LTC3122
SGND PGND
R
C
137k
C
C
150pF
SW
L1
1µH
R2
121k
R1
487k
C
F
12pF
C
VCC
4.7µF
C1
100nF
C
OUT
47µF
V
OUT
6V
833mA
R
T
17.4k
V
IN
2.5V TO 4.2V
C
IN
4.7µF
ONOFF
C
IN
, C
VCC
: 4.7µF, 6.3V, X7R, 1206
C1: 100nF, 6.3V, X7R, 1206
C
OUT
: 47µF, 10V, X7R, 1812
L1: TDK SPM6530T-1ROM120
3122 TA03a
V
IN
SD
PWM/SYNC
RT
V
CC
V
OUT
CAP
FB
V
C
LTC3122
SGND PGND
R
C
200k
C
C
560pF
SW
L1
3.3µH
R2
113k
R1
1.02M
C
F
10pF
C
VCC
4.7µF
C1
100nF
C
OUT
22µF
V
OUT
12V
180mA
R
T
57.6k
V
IN
1.8V TO 3V
C
IN
4.7µF
ONOFF
C
IN
, C
VCC
: 4.7µF, 6.3V, X7R, 1206
C1: 100nF, 6.3V, X7R, 1206
C
OUT
: 22µF, 16V, X7R, 1812
L1: TDK SPM6530T-3R3M
100µs/DIV
80mA 80mA
833mA
3122 TA02b
OUTPUT
CURRENT
500mA/DIV
V
OUT
500mV/DIV
AC-COUPLED
V
IN
= 3.6V
V
IN
(V)
1.6
INPUT CURRENT (A)
2.3
2.1
1.7
1.3
1.1
1.9
1.5
0.9
0.7
0.5
EFFICIENCY (%)
100
90
70
50
40
80
60
30
20
10
0
2.2 2.4 2.6 2.81.8
3122 TA03b
2 3.23
EFFICIENCY
INPUT CURRENT