Datasheet

LTC3406AB
13
3406abfa
APPLICATIONS INFORMATION
For the feedback resistors, choose R1 = 316k. R2 can
then be calculated from Equation (2) to be:
R
V
Rk
OUT
2
06
1 1 1000=−
⎛
⎝
⎜
⎞
⎠
⎟
=
.
(4)
Figure 5 shows the complete circuit along with its ef-
fi ciency curve.
Figure 5
OUTPUT CURRENT (mA)
0.1
EFFICIENCY (%)
10
1000
100
90
80
70
60
50
40
30
20
10
0
3406B G03
1 100
V
OUT
= 2.5V
V
IN
= 2.7V
V
IN
= 3.6V
V
IN
= 4.2V
V
OUT
200mV/DIV
I
L
500mA/DIV
I
LOAD
500mA/DIV
20μs/DIV
V
IN
= 3.6V
V
OUT
= 2.5V
I
LOAD
= 200mA TO 450mA
3406B F10
Load Step
V
IN
C
IN
†
4.7μF
CER
V
IN
LTC3406AB
RUN
3
2.2μH*
22pF
1M
316k
3406AB TA09a
5
4
1
2
SW
V
FB
GND
C
OUT
**
10μF
CER
2.5V, 600mA
V
OUT
*MURATA LQH32CN2R2M33
** TAIYO YUDEN JHK316BJ106ML
†
TAIYO YUDEN JMK212BJ475MG
V
OUT
100mV/DIV
I
L
500mA/DIV
I
LOAD
500mA/DIV
20μs/DIV
V
IN
= 3.6V
V
OUT
= 2.5V
I
LOAD
= 300mA TO 600mA
3406B F16
Load Step