LT3467AIS67 Ver la hoja de datos (PDF) - Linear Technology

Número de pieza

componentes Descripción

Fabricante

LT3467AIS67

1.1A Step-Up DC/DC Converter with Integrated Soft-Start

Linear Technology 

LT3467/LT3467A

PIN FUNCTIONS (DFN/TSOT)

FB (Pin 1/Pin 3): Feedback Pin. Reference voltage is 1.255V.

Connect resistive divider tap here. Minimize trace area at

FB. Set VOUT = 1.255V(1 + R1/R2).

GND (Pins 2, 5, 9/Pin 2): Ground. Tie directly to local

ground plane.

SW (Pins 3, 4/Pin 1): Switch Pin. (Collector of internal

NPN power switch) Connect inductor/diode here and

minimize the metal trace area connected to this pin to

minimize EMI.

VIN (Pin 6/Pin 6): Input Supply Pin. Must be locally

bypassed.

SS (Pin 7/Pin 5): Soft-Start Pin. Place a soft-start capacitor

here. Upon start-up, 4μA of current charges the capacitor

to 1.255V. Use a larger capacitor for slower start-up. Leave

floating if not in use.

SHDN (Pin 8/Pin 4): Shutdown Pin. Tie to 2.4V or more

to enable device. Ground to shut down.

BLOCK DIAGRAM

SS

VIN

1.255V

REFERENCE

VOUT

R1 (EXTERNAL)

FB

R2 (EXTERNAL)

250k

+

A1

–

SHUTDOWN

SHDN

FB

– COMPARATOR

RC

A2

+

R

Q

S

CC

3

RAMP

GENERATOR

1.3MHz

OSCILLATOR*

*2.1MHz FOR LT3467A

SW

DRIVER

Q1

0.01Ω

GND

3467 F01

Figure 1. Block Diagram

3467afe

5

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