NX2147

1

Rev. 1.6

03/09/09

Rev. 1.8

12/28/09

TYPICAL APPLICATION

DESCRIPTION

The NX2147 controller IC is a step down switching con-

troller with ability to dynamically adjust the output volt-

age designed for applications such as Graphic Proces-

sor Core voltage in Notebook PC products. It allows

this by adjusting the reference input of the PWM

comprator as oppose to the traditional method of feed-

back adjustment. This device has three mode of opera-

tions; a) Constant ON Time Synchronous Mode, b) Non

Synchronous PFM mode or c) Ultrasonic PFM mode of

operation. When selected in Non Synchronous mode,

the device automatically disables the synchronous

MOSFET in order to improve efficiency at light load.

This device provides excellent dynamic response and

nearly constant frequency for operation from 4.5V to

24V of input voltage operation. Other features of the

device are; internal logic level signal MOSFETs for out-

put dynamic voltage adjustment, internal boost schotcky

diode, less than 1uA VIN shutdown current, adjustable

current limiting using lower MOSFET Rds-On and feed-

back UVLO followed by latchdown, overvoltage protec-

tion , internal digital soft start and soft stop shutdown

using and internal 20 ohm MOSFET pull down.

n Output voltage can be dynamically changed

n Internal Boost Schottky Diode

n

Ultrasonic mode operation available

n Bus voltage operation from 4.5V to 24V

n Less than 1uA VIN shutdown current with Enable

low

n Excellent dynamic response with constant on time

control

n Selectable between Synchronous CCM mode and

diode emulation mode to improve efficiency at

light load

n Programmable switching frequency

n Current limit and FB UVLO with latch off

n Over voltage protection with latch off

n Pb-free and RoHS compliant

ORDERING INFORMATION

FEATURES

SINGLE CHANNEL MOBILE PWM CONTROLLER WITH

DYNAMIC VOLTAGE ADJUSTMENT

APPLICATIONS

n Notebook PCs and Desknotes

n Tablet PCs/Slates

n On board DC to DC such as

12V to 3.3V, 2.5V or 1.8V

n Hand-held portable instruments

PRODUCTION DATA SHEET

Figure1 - Typical application of NX2147

Device

Temperature

Package

Pb-Free

NX2147CMTR

3X3 MLPQ-16L

Yes

Pb Free Product

7

VIN 7V~22V

TON

HDRV

BST

SW

LDRV

VREF_OC

VOUT

ENSW

/MODE

5V

10

VCC

PVCC

Vout (see table above) /12A

AGND

1MEG

9

2

15

6

1

10

8

11

13

12

16

1u

1u

2R5TPE330MC

200k

1u

2x10uF

1n

FDS6294

FDS6676AS

1uH

330uF

PGND

D1

4

D0

5

GPIO0

14

GPIO1

6

VP

3

10n

0.1u

100k

88.7k

634k

LOAD

2.2

GP IO0 GP IO1 VOUT(V)

1

1

1.17

0

1

1.09

1

0

0.95

0

0

0.9