RT9045 Ver la hoja de datos (PDF) - Richtek Technology

Número de pieza

componentes Descripción

Fabricante

RT9045

Cost-Effective, 1.8A Sink/Source Bus Termination Regulator

Richtek Technology 

RT9045

Function Block Diagram

REFEN

VCNTL

VIN

Current Limit

Thermal Protection

+EA

-

VOUT

GND

Functional Pin Description

VIN

Input voltage which supplies current to the output pin.

Connect this pin to a well-decoupled supply voltage. To

prevent the input rail from dropping during large load

transient, a large, low ESR capacitor is recommended to

use. The capacitor should be placed as close as possible

to the VIN pin.

GND (Exposed Pad)

Common Ground. The exposed pad must be soldered to

a large PCB and connected to GND for maximum power

dissipation.

VCNTL

VCNTL supplies the internal control circuitry and provides

the drive voltage. The driving capability of output current is

proportioned to the VCNTL. Connect this pin to 5V bias

supply to handle large output current with at least 1μF

capacitor from this pin to GND. An important note is that

VIN should be kept lower or equal to VCNTL.

REFEN

Reference voltage input and active low shutdown control

pin. Two resistors dividing down the VIN voltage on this pin

to create the regulated output voltage. Pulling this pin to

ground turns off the device by an open-drain, such as

2N7002, signal N-MOSFET.

VOUT

Regulator output. VOUT is regulated to REFEN voltage

that is used to terminate the bus resistors. It is capable of

sinking and sourcing current while regulating the output

rail. To maintain adequate large signal transient response,

typical value of 10μF ceramic capacitors are recommended

to reduce the effects of current transients on VOUT.

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DS9045-04 August 2011

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