ltc3528b-2 Linear Technology Corporation, ltc3528b-2 Datasheet - Page 6

• Manufacturer Part Number: ltc3528b-2
• Description: 1a, 2mhz Synchronous Step-up Dc/dc Converter In 2mm ? 3mm Dfn
• Manufacturer: Linear Technology Corporation

LTC3528B-2
TYPICAL PERFORMANCE CHARACTERISTICS
PIN FUNCTIONS
SHDN (Pin 1): Logic Controlled Shutdown Input. There is
an internal 4MΩ pull-down resistor on this pin.
FB (Pin 2): Feedback Input. Connect resistor divider tap
to this pin. The output voltage can be adjusted from 1.6V
to 5.25V by:
PGOOD (Pin 3): Power Good Comparator Output. This
open-drain output is low when V
lation voltage.
V
of the Internal Synchronous Rectifi er. PCB trace length
from V
should be as short and wide as possible.
6
OUT
• SHDN = High: Normal operation
• SHDN = Low: Shutdown, quiescent current < 1μA
V
OUT
(Pin 4): Output Voltage Sense and Drain Connection
OUT
= 1.20V • 1+
to the output fi lter capacitor (4.7μF minimum)
100mV/DIV
200mA/DIV
CURRENT
LOAD
V
OUT
⎛
⎝ ⎜
V
V
C
L = 2.2μH
LOAD CURRENT = 100mA TO 550mA
Load Step Response
(3.6V to 5V)
IN
OUT
OUT
= 3.6V
R2
R1
= 5V
= 10μF
⎞
⎠ ⎟
FB
20μs/DIV
< 10% from its regu-
35282 G22
SW (Pin 5): Switch Pin. Connect inductor between SW
and V
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
PGND (Pin 6): Power Ground. Provide a short direct PCB
path between PGND and the (–) side of the input and
output capacitors.
SGND (Pin 7): Signal Ground. Provide a short direct PCB
path between SGND and the (–) side of the input and
output capacitors.
V
of 1μF ceramic decoupling capacitor from this pin to
ground.
Exposed Pad (Pin 9): The Exposed Pad must be soldered
to the PCB ground plane. It serves as another ground
connection and as a means of conducting heat away
from the die.
IN
(Pin 8): Battery Input Voltage. Connect a minimum
100mV/DIV
100mA/DIV
IN
CURRENT
. Keep PCB trace lengths as short and wide as
LOAD
V
OUT
(T
Load Step Response
(1.2V to 3.3V)
A
V
V
C
L = 2.2μH
LOAD CURRENT = 20mA TO 170mA
IN
OUT
OUT
= 25°C unless otherwise noted)
= 1.2V
= 3.3V
= 10μF
IN
20μs/DIV
to minimize EMI.
35282 G24
3528b2f