7

44411f

LTC4441/LTC4441-1

BLOCK DIAGRA

1.09V

IN

1.21V

UVLO

REG

EN

INB

1.21V

0.45V

SHUTDOWN

FB

EN/SHDN

SGND

SHDN

THERMAL

SHUTDOWN

BIAS

LEADING

EDGE DELAY

Q1

P1

OUT

PGND

RBLANK

BLANK

4441 BD

N1

MB

FOR 10-LEAD

LTC4441

ONLY

APPLICATIO S I FOR ATIO

Overview

Power MOSFETs generally account for the majority of

power lost in a converter. It is important to choose not only

the type of MOSFET used, but also its gate drive circuitry.

The LTC4441/LTC4441-1 is designed to drive an N-chan-

nel power MOSFET with little efficiency loss. The LTC4441/

LTC4441-1 can deliver up to 6A of peak current using a

combined NPN Bipolar and MOSFET output stage. This

helps to turn the power MOSFET fully “on” or “off” with a

very brief transition region.

The LTC4441/LTC4441-1 includes a programmable linear

regulator to regulate the gate drive voltage. This regulator

provides the flexibility to use either standard threshold or

logic level MOSFETs.

An internal, P-channel low dropout linear regulator pro-

driver logic circuitry as shown in Figure 1. The regulator

output voltage can be programmed between 5V and 8V

SGND and a center tap connected to the FB pin. The

regulator needs an R1 value of around 330k to ensure loop