APW7057K 데이터 시트보기 (PDF) - Anpec Electronics

부품명

상세내역

제조사

APW7057K

High Power Step-Down Synchronous DC/DC Controller

Anpec Electronics 

APW7057

Functional Pin Description

nal resistive divider across the output (V ). The

OUT

output voltage is determined by:

VOUT

=

0.8V(1+

ROUT

RGND

)

where ROUT is the resistor connected between VOUT

and FB while RGND is the resistor connected from FB

to GND.

OCSET (Pin 7)

This pin serves two functions: as a shutdown con-

trol and for setting the over current limit threshold.

Pulling this pin below 1.25V shuts the controller

down, forcing the UGATE and LGATE signals to be

at 0V. A soft start cycle will be initiated upon the re-

lease of this pin.

A resistor (Rocset) connected between this pin and

the drain of the high side MOSFET will determine

the over current limit. An internally generated 40uA

current source will flow through this resistor, creat-

ing a voltage drop. This voltage will be compared

with the voltage across the high side MOSFET. The

threshold of the over current limit is therefore given

by:

IOI = 40uA x ROCSET

RDS(ON)

An over current condition will cycle the soft start

function. After three consecutive cycles and if the

fault condition persists, the controller will be shut

down. To restart the controller, either recycle the VCC

supply or momentarily pull the OSCSET pin below

1.25V.

PHASE (Pin 8)

This pin is connected to the source of the high-side

MOSFET and is used to monitor the voltage drop

across the high-side MOSFET for over-current

protection.

Typical Characteristics

Reference Voltage vs. Junction Temperature

0.812

0.808

0.804

0.800

0.796

0.792

0.788

-50 -25 0 25 50 75 100 125 150

Junction Temperature (oC)

Switching Frequency vs. Junction Temperature

350

340

330

320

310

300

290

280

270

260

250

-50 -25 0 25 50 75 100 125 150

Junction Temperature (°C)

Copyright  ANPEC Electronics Corp.

6

Rev. A.3 - Oct., 2003

www.anpec.com.tw

Share Link: