LTC3415 datasheet(10/36 Pages) LINER

10 / 36 page

LTC3613

3613fa

FUNCTIONAL DIAGRAM

ICMP

(gm(EA) = 1.7mS)

0.645V

0.555V

0.6V

1μA

IREV

LOGIC

CONTROL

PLL

SYSTEM

ONE-SHOT

TIMER

CLOCK

DETECT

OSCILLATOR

LDO

OUT

SVIN

4.2V

TIME

ADJUST

STOP

START

1.2V

0.75V

–

(A = 1)

RPGD

PGOOD

MODE/PLLIN

VRNG

ITH

VOSNS

–

VOSNS

TRACK/SS

SENSE–

SENSE+

PGND

EXTVCC

BO0ST

INPUT SUPPLY

COUT

RFB2

RFB1

RSENSE

PVIN

INTVCC

SGND

RITH

CITH1

INTVCC

3.65V

UVLO

4.6V

VOUT

RUN

1.3μA

CVCC

VIN

CIN

VOUT

CIN

CSS

3613 FD

–

TG DRV

BG DRV

CLOCK

OPERATION

Main Control Loop

The LTC3613 uses valley current mode control to regulate

the output voltage in a monolithic, all N-channel MOSFET

DC/DC step-down converter. Current control is achieved by

sensing the inductor current across SENSE+ and SENSE–,

either by using an explicit resistor connected in series with

the inductor or by implicitly sensing the inductor’s resis-

tive (DCR) voltage drop through an RC filter connected

across the inductor.

In normal steady-state operation, the top MOSFET is turned

on for a fixed time interval proportional to the delay in the

one-shot timer. The PLL system adjusts the delay in the

one-shot timer until the top MOSFET turn-on is synchro-

nized either to the internal oscillator or the external clock

input if provided. As the top MOSFET turns off, the bottom

MOSFET turns on with a small time delay (dead time) to

avoid shoot-through current. The next switching cycle is

initiated when the current comparator, ICMP, senses that

inductor current has reached the valley threshold point

(Refer to Functional Diagram)

LTC3415 Datasheet(PDF) 10 Page - Linear Technology

LTC3415 Datasheet(HTML) 10 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

Datasheet Download

Link URL