LM2744 datasheet(2/32 Pages) TI1

2 / 32 page

BOOT

ISEN

PGND

VCC

PWGD

FREQ

SS/TRACK

SGND

EAO

VREF

BOOT

ISEN

SGND

VCC

PWGD

FREQ

SS/TRACK

VREF

EAO

PGND

VCC = 3.3V

VIN = 3.3V

VOUT = 1.2V@4A

RFB2

CC2

RC1

RCS

RFADJ

RCC

CCC

CBOOT

CIN1,2

CC1

RFB1

CO1,2

LM2744

RC2

CC3

RPULL-UP

External

Reference

0.5 to 1.5V

CSS

LM2744

SNVS292E – SEPTEMBER 2004 – REVISED JANUARY 2012

www.ti.com

Typical Application

Figure 1. Typical Application Circuit

Connection Diagram

Figure 2. 14-Lead Plastic TSSOP

θJA = 155°C/W

Pin Functions

Pin Descriptions

BOOT (Pin 1) - Bootstrap pin. This is the supply rail for the high-side gate driver. When the high-side MOSFET turns on, the voltage on this

pin should be at least one gate threshold above the regulator input voltage VIN to properly turn on the MOSFET. See MOSFET Gate Drivers

in the Application Information section for more details on how to select MOSFETs.

LG (Pin 2) - Low-gate drive pin. This is the gate drive for the low-side N-channel MOSFET. This signal is interlocked with the high-side gate

drive HG (Pin 14), so as to avoid shoot-through.

PGND (Pin 3) - Power ground. This is also the ground for the low-side MOSFET driver. This pin must be connected on the PCB ground

plane, which is usually also the system ground.

SGND (Pin 4) - Signal ground. It should be connected appropriately to the ground plane with due regard to good layout practices in

switching power regulator circuits.

VCC (Pin 5) Supply rail for the control sections of the IC.

PWGD (Pin 6) - Power Good pin. This is an open drain output, which is typically meant to be connected to VCC or any other low voltage

source through a pull-up resistor. The voltage on this pin is thus pulled low under output fault conditions (undervoltage or overvoltage) and

also under UVLO.

ISEN (Pin 7) - Current limit threshold setting pin. This sources a fixed 40 µA current. A resistor of appropriate value should be connected

between this pin and the drain of the low-side MOSFET (switch node).

EAO (Pin 8) - Output of the error amplifier. The voltage level on this pin is compared with an internally generated ramp signal to determine

the duty cycle. This pin is necessary for compensating the control loop.

Submit Documentation Feedback

Product Folder Links: LM2744

LM2744 Datasheet(PDF) 2 Page - Texas Instruments

LM2744 Datasheet(HTML) 2 Page - Texas Instruments

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

Datasheet Download

Link URL