PM6685(2005) データシートの表示（PDF） - STMicroelectronics

部品番号

コンポーネント説明

メーカー

PM6685
(Rev.:2005)

DUAL STEP-DOWN CONTROLLER WITH AUXILARY VOLTAGES FOR NOTEBOOK SYSTEM POWER

STMicroelectronics 

PM6685

DUAL STEP-DOWN CONTROLLER WITH AUXILARY VOLTAGES

FOR NOTEBOOK SYSTEM POWER

Preliminary Data

Features

■ CONSTANT ON TIME TOPOLOGY ALLOWS

VERY FAST LOAD TRANSIENTS

■ 6V TO 28V INPUT VOLTAGE RANGE

■ FIXED 5V-3.3V OUTPUT VOLTAGES

■ 5V AND 3.3V ALWAYS VOLTAGES

AVAILABLE DELIVER 100mA PEAK

CURRENT

■ 1.23V ± 1% REFERENCE VOLTAGE

AVAILABLE

■ NO RSENSE CURRENT SENSING USING

LOW SIDE MOSFETs’ RDS(on)

■ ACCURATE CURRENT SENSE WITH

RSENSE

■ NEGATIVE CURRENT LIMIT

■ SOFT START INTERNALLY FIXED AT 2ms

■ SOFT OFF FOR OUTPUT DISCHARGE

■ LATCHED OVP AND UVP

■ SELECTABLE PULSE SKIPPING AT LIGHT

LOADS

■ SELECTABLE MINIMUM FREQUECY

(25kHz) IN PULSE SKIP MODE

■ 4 mW MAXIMUM QUIESCENT POWER

■ INDIPENDENT POWER GOOD SIGNALs

■ OUTPUT VOLTAGE RIPPLE

COMPENSATION

VFQFPN-32 5X5

Description

PM6685 is a dual step-down controller

specifically designed to provide extremely high

efficiency conversion, with lossless current

sensing technique. The constant on-time

architecture assures fast load transient response

and the embedded voltage feed-forward provides

nearly constant switching frequency operation. An

embedded integrator control loop compensates

the DC voltage error due to the output ripple.

Pulse skipping technique increases efficiency at

very light load. Moreover a minimum switching

frequency of 25kHz is selectable to avoid audio

noise issues. The PM6685 provides a selectable

switching frequency, allowing either 200kHz/

300kHz, 300kHz/400Khz or 400kHz/500kHz

operation of the 5V/3.3V switching sections...

Applications

■ NOTEBOOK COMPUTERS

■ TABLET PC OR SLATES

■ MOBILE SYSTEM POWER SUPPLY

■ 3-4 CELLS Li+ BATTERY POWERED

DEVICES

Order codes

Part number

PM6685

Marking

PM6685

Package

VFQFPN-32 5X5

September 2005

This is preliminary information on a new product now in development or undergoing evaluation.

Details are subject to change without notice.

Packing

TAPE & REEL

Rev 1

1/16

www.st.com

16

Share Link: