Datasheet

LTC3422
14
3422fa
2-Cell to 3.3V at 600mA Application
Figure 3. Typical Error Amplifier Compensation
APPLICATIO S I FOR ATIO
WUUU
1.216V
FB
6
V
OUT
10
V
C
C
C1
C
C2
3422 F03
R
Z
R2
R1
7
–
+
g
m
ERROR
AMPLIFIER
TYPICAL APPLICATIO S
U
C
SS
0.1µF
C
C2
22pF
C
C1
1nF
OFF ON
R
Z
15k
C
OUT
*
22µF
C
IN
*
4.7µF
V
IN
1.8V TO 3.2V
2 CELLS
+
C
B
2.2nF
*LOCATE COMPONENTS CLOSE TO PINS
C
IN
: TAIYO YUDEN X5R JMK212BJ475MD
C
OUT
: TAIYO YUDEN X5R JMK325BJ226MM
L1: TDK RLF7030T-4R7M3R4
R
T
28k
R1
931k
V
OUT
3.3V
600mA
R2
549k
R
B
301k
3422 TA02a
SS
V
C
BURST
SHDN FB
SYNC V
OUT
R
T
GND
V
IN
LTC3422
L1
4.7µH
SW
LOAD CURRENT (mA)
30
EFFICIENCY (%)
POWER LOSS (mW)
90
100
20
10
80
50
70
60
40
0.1 10 100 1000
3422 TA02b
0
10000
1
1000
100
10
0
1
V
IN
= 3V
V
IN
= 2.4V
V
IN
= 1.8V
V
IN
= 3V
V
IN
= 2.4V
V
IN
= 1.8V
V
IN
= 1.8V
V
IN
= 2.4V
V
IN
= 3V
V
IN
= 1.8V
V
IN
= 2.4V
V
IN
= 3V
BURST EFFICIENCY
PWM EFFICIENCY
PWM POWER LOSSES
BURST POWER LOSSES
2-Cell to 3.3V Efficiency and Power Loss at 1MHz
C
SS
0.1µF
C
C2
22pF
C
C1
1nF
OFF ON
R
Z
15k
C
OUT
*
10µF
C
IN
*
10µF
V
IN
0.9V TO 1.6V
1 CELL
C
B
2.2nF
*LOCATE COMPONENTS CLOSE TO PINS
C
IN
, C
OUT
: TAIYO YUDEN X5R JMK212BJ106MM
L1: TDK RLF7030T-4R7M3R4
R
T
28k
R1
931k
V
OUT
3.3V
240mA
R2
549k
R
B
374k
3422 TA03a
SS
V
C
BURST
SHDN FB
SYNC V
OUT
R
T
GND
V
IN
LTC3422
L1
4.7µH
SW
+
LOAD CURRENT (mA)
30
EFFICIENCY (%)
POWER LOSS (mW)
90
100
20
10
80
50
70
60
40
0.1 10 100 1000
3422 TA03b
0
10000
1
1000
100
10
0
1
V
IN
= 1.6V
V
IN
= 1.25V
V
IN
= 0.9V
V
IN
= 0.9V
V
IN
= 1.25V
V
IN
= 1.6V
BURST EFFICIENCY
PWM EFFICIENCY
PWM POWER LOSSES
BURST POWER LOSSES
1-Cell to 3.3V at 240mA Application
1-Cell to 3.3V Efficiency and Power Loss at 1MHz