LTC3528 datasheet(6/16 Pages) LINER

6 / 16 page

LTC3528/LTC3528B

3528fa

PIN FUNCTIONS

Load Step Response (Fixed

Frequency, 1.2V to 3.3V)

Load Step Response (Burst Mode

Operation, 1.2V to 3.3V, LTC3528)

SHDN (Pin 1): Logic Controlled Shutdown Input. There is

an internal 4MΩ pull-down resistor on this pin.

• SHDN = High: Normal operation

• SHDN = Low: Shutdown, quiescent current < 1μA

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:

VOUT = 1.20V • 1+

PGOOD (Pin 3): Power Good Comparator Output. This

open-drain output is low when VFB < 10% from its regu-

lation voltage.

VOUT (Pin 4): Output Voltage Sense and Drain Connection

of the Internal Synchronous Rectiﬁer. PCB trace length

from VOUT to the output ﬁlter capacitor (4.7μF minimum)

should be as short and wide as possible.

SW (Pin 5): Switch Pin. Connect inductor between SW

and VIN. 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 VIN to minimize EMI.

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.

Load Step Response (Fixed

Frequency, 3.6V to 5V)

Load Step Response (Burst Mode

Operation, 3.6V to 5V, LTC3528)

VOUT and IIN During Soft-Start

Burst Mode Waveforms

5μs/DIV

3528 G20

VIN = 3.6V

VOUT = 5V

COUT = 22μF

CFF = 33pF

ILOAD = 30mA

VOUT

20mV/DIV

INDUCTOR

CURRENT

100mA/DIV

VOUT

1V/DIV

SHDN PIN

200μs/DIV

3528 G21

VIN = 1.2V

VOUT = 3.3V

COUT = 10μF

L = 4.7μH

IIN

200mA/DIV

VOUT

100mV/DIV

20μs/DIV

3528 G22

VIN = 3.6V

VOUT = 5V

COUT = 10μF

L = 4.7μH

LOAD

CURRENT

200mA/DIV

VOUT

100mV/DIV

50μs/DIV

3528 G23

VIN = 3.6V

VOUT = 5V

COUT = 10μF

L = 4.7μH

LOAD

CURRENT

200mA/DIV

VOUT

100mV/DIV

50μs/DIV

3528 G24

VIN = 1.2V

VOUT = 3.3V

COUT = 10μF

L = 4.7μH

LOAD

CURRENT

100mA/DIV

VOUT

100mV/DIV

50μs/DIV

3528 G25

VIN = 1.2V

VOUT = 3.3V

COUT = 10μF

L = 4.7μH

LOAD

CURRENT

100mA/DIV

TYPICAL PERFORMANCE CHARACTERISTICS (T

A = 25°C unless otherwise noted)

LTC3528 Datasheet(PDF) 6 Page - Linear Technology

LTC3528 Datasheet(HTML) 6 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Datasheet Download

Link URL