LTC3526-2/LTC3526B-2
6
35262b2fc
SW (Pin 1): Switch Pin. Connect inductor between SW and
V
IN
. Keep PCB trace lengths as short and wide as possible
to reduce EMI. If the inductor current falls to zero or SHDN
is low
, an internal anti-ringing switch is connected from
SW to V
IN
to minimize EMI.
GND (Pin 2): Signal and
Power Ground. Provide a short
direct PCB path between GND and the (–) side of the input
and output capacitors.
V
IN
(Pin 3): Input Supply Pin. Connect a minimum of 1µF
ceramic decoupling capacitor from this pin to ground
using short direct PCB traces.
SHDN (Pin 4): Logic Controlled Shutdown Input. There
is an internal 4MΩ pull-down
on this pin.
• SHDN =
High: Normal operation
• SHDN =
Low: Shutdown, quiescent current < 1µA
FB (Pin 5): Feedback Input
to the g
m
Error Amplifier.
Connect resistor divider tap to this pin. The top of the divider
connects to the output capacitor, the bottom of the divider
connects to GND. Referring to the Block Diagram, the output
voltage can be adjusted from 1.6V to 5.25V by:
V V
R
R
OUT
= +
1 195 1
2
1
. •
V
OUT
(Pin 6): Output voltage sense and drain of the internal
synchronous rectifier. PCB trace from V
OUT
to the output
filter capacitor (4.7µF minimum) should be as short and
wide as possible.
GND (Exposed Pad Pin 7): The Exposed Pad must be sol-
dered to the PCB ground plane. It serves as an additional
ground connection and as a means of conducting heat
away from the package.
Load Step Response (from Burst
Mode Operation)
Load Step Response
(Fixed Frequency)
LOAD
CURRENT
50mA/DIV
100µs/DIVV
IN
= 1.2V
V
OUT
= 3.3V
50mA TO 100mA STEP
C
OUT
= 10µF
35262b2 G21
V
OUT
100mV/DIV
AC-COUPLED
LOAD
CURRENT
50mA/DIV
50µs/DIVV
IN
= 1.2V
V
OUT
= 3.3V
5mA TO 100mA STEP
C
OUT
= 10µF
35262b2 G22
V
OUT
100mV/DIV
AC-COUPLED
typicAl perForMAnce chArActeristics
pin Functions
