lt3467aes67 Linear Technology Corporation, lt3467aes67 Datasheet - Page 7

• Manufacturer Part Number: lt3467aes67
• Description: 1.1a Step-up Dc/dc Converter With Integrated Soft-start
• Manufacturer: Linear Technology Corporation

APPLICATIONS
Table 1. Inductor Manufacturers.
Sumida
TDK
Murata
FDK
Soft-Start
The soft-start feature provides a way to limit the inrush
current drawn from the supply upon startup. An internal
250k resistor charges the external soft start capacitor to
1.255V. After the capacitor reaches 0.15V the rate of
voltage rise at the output of the comparator A1 tracks the
rate of voltage rise of the soft-start capacitor. This limits
the inrush current drawn from the supply during startup.
Once the part is shut down, the soft start capacitor is
quickly discharged to 0.4V, then slowly discharged through
the 250k resistor to ground. If the part is to be shut down
and re-enabled in a short period of time while soft-start is
used, you must ensure that the soft-start capacitor has
enough time to discharge before re-enabling the part.
Typical values of the soft-start capacitor range from 10nF
to 200nF.
2.6V TO
4.2V
V
IN
Figure 2. Single Li-Ion Cell to 5V Boost Converter
(Same as 1st Page Application)
C1, C2: X5R OR X7R, 6.3V
D1: ON SEMICONDUCTOR MBRM120
L1: SUMIDA CR43-2R7
0.047μF
[phone]
[phone]
[phone]
[phone]
OFF ON
C1
4.7μF
C3
U
INFORMATION
U
SHDN
SS
V
IN
LT3467
2.7μH
GND
L1
W
SW
FB
www.sumida.com
www.tdk.com
www.murata.com
www.fdk.co.jp
D1
R1
402k
R2
133k
U
C4
3.3pF
3467 TA05a
C2
15μF
V
5V
765mA AT V
540mA AT V
360mA AT V
OUT
0.5A/DIV
IN
IN
IN
0.5A/DIV
I
1V/DIV
SUPPLY
I
1V/DIV
= 4.2V,
= 3.3V,
= 2.6V
SUPPLY
V
V
OUT
OUT
Startup with 47nF Soft-Start Capacitor
Startup without Soft-Start Capacitor
Supply Current of Figure 2 During
Supply Current of Figure 2 During
0.1ms/DIV
0.5ms/DIV
LT3467/LT3467A
3467afc
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