RT8885A Ver la hoja de datos (PDF) - Richtek Technology

Número de pieza

componentes Descripción

Fabricante

RT8885A

Dual Output 3-Phase + 2-Phase PWM Controller For CPU and GPU Core Power Supply

Richtek Technology 

Operation

The RT8885A adopts G-NAVPTM (Green-Native AVP),

which is a Richtek proprietary topology derived from finite

DC gain compensator in constant on-time control mode.

G-NAVPTM is based on the finite gain peak current mode

with CCRCOT (Constant Current Ripple Constant On-Time)

topology. The control loop consists of PWM modulators

with power stages, current sense amplifiers and an error

amplifier as shown in functional block diagram. The

HS_FET on-time is determined by CCRCOT on-time

generator. Low offset current sense amplifiers are used

for current balance, loop control and over current detection.

RT8885A

By increasing the loading current, the current signal is

rose to increase the steady state COMP voltage, and then

the output voltage is decreased to achieving AVP.

A near-DC offset canceling is added to the output of EA to

eliminate the inherent output offset of finite gain peak

current mode controller. After EN go high, the internal ADC

sense pin setting for VINITAL, ICCMAX, over current

protection and internal compensation ramp setting. The

internal ADC also sense IMON and TSEN pin voltage for

INTEL reporting.

Copyright ©2014 Richtek Technology Corporation. All rights reserved.

DS8885A-01 January 2014

is a registered trademark of Richtek Technology Corporation.

www.richtek.com

7

Share Link: