LTC3525-3.3 Linear Technology Corporation, LTC3525-3.3 Datasheet - Page 7

• Manufacturer Part Number: LTC3525-3.3
• Description: 400mA Micropower Synchronous Step-Up DC/DC Converter
• Manufacturer: Linear Technology Corporation

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PI FU CTIO S
BLOCK DIAGRA
_____
SHDN (Pin 1): Logic Controlled Shutdown Input. Connect
to a voltage >1V to enable the LTC3525. Connect to a
voltage <0.4V to disable the LTC3525.
GND (Pins 2, 5): Ground.
V
V
+ 0.2V typical), it is powered from V
bypass capacitor from V
1µF is recommended.
IN
IN
U
(Pin 3): Input Voltage. The LTC3525 is powered from
until V
U
OUT
SHDN
exceeds V
1
U
SHUTDOWN
SHUTDOWN
V
THERMAL
OUT
V
UVLO
V
BEST
REF
IN
SHUTDOWN
IN
. Once V
W
to GND. A minimum value of
STARTUP
VB
SHUTDOWN
V
REF
TSD
UVLO
OUT
V
OUT
SEL
is greater than (V
. Place a ceramic
GATE DRIVERS
CONDUCTION
ANTI-CROSS
LOGIC
AND
I
PK
IN
I
VAL
WAKE
SW
COMPARATOR
6
GND
INTEGRATOR
V
Synchronous Rectifier. Connect the output filter capacitor
from V
10µF ceramic is recommended. Use 22µF for reduced
output ripple. The output disconnect feature disconnects
V
SW (Pin 6): Switch Pin. Connect an inductor from this pin
to V
SW and V
to minimize EMI.
2
–
+
I
PK
ADJUST
OUT
OUT
OFFSET
IN
COMPARATOR
(Pin 4): Output Voltage Sense and the Output of the
from V
. An internal antiringing resistor is connected across
I
VALLEY
OUT
–
+
+
–
IN
ADJUST
OFFSET
to GND, close to the IC. A minimum value of
after the inductor current has dropped to zero
IN
COMPARATOR
LTC3525-3.3/LTC3525-5
when SHDN is <0.4V.
SLEEP
–
+
+
–
ADJUST
SWITCH
WELL
V
3
IN
FB
V
REF
3525 BD
4
V
OUT
7
3525f