NX2116/2116A/2116B/2117/2117A

1

Rev. 3.0

03/14/06

TYPICAL APPLICATION

DESCRIPTION

The NX2116/2117 family of products are synchronous

Buck controller IC designed for step down DC to DC

converter applications. They are optimized to convert

bus voltages from 2V to 25V to as low as 0.8V output

voltage. The NX2116 and 2117 offer an Enable pin that

can be used to program the converter's start up voltage

using an external divider from bus voltage. These prod-

ucts operate at fixed internal frequency of 300kHz, ex-

cept that NX2116A operates at 600kHz and 2116B at

1MHz frequency. These products employ loss-less cur-

rent limiting protection by sensing the Rdson of syn-

chronous MOSFET followed by latch out feature. Feed-

back under voltage triggers Hiccup.

Other features are; 5V gate drive, Power good indica-

tor, Adaptive deadband control, Internal digital soft start;

Vcc undervoltage lock out and shutdown capability via

the enable pin or comp pin.

n Bus voltage operation from 2V to 25V

n Power Good indicator available in NX2116

n Fixed 300kHz, 600kHz and 1MHz for NX2116 and

300kHz, 600kHz for NX2117 family.

n Internal Digital Soft Start Function

n Less than 50 nS adaptive deadband

n Enable pin to program BUS UVLO for NX2116/2117

n Programmable current limit triggers latch out by

sensing Rdson of

Synchronous MOSFET

n No negative spike at Vout during startup and

shutdown

ORDERING INFORMATION

FEATURES

SYNCHRONOUS PWM CONTROLLER WITH

CURRENT LIMIT, POWER GOOD & OVER VOLTAGE

APPLICATIONS

n Graphic Card on board converters

n Memory Vddq Supply

n On board DC to DC such as 2V to 3.3V, 2.5V or

1.8V

n ADSL Modem

PRELIMINARY DATA SHEET

Device

Temperature

Package

Frequency

Pb-Free

NX2116CMTR

MLPD-10L

300kHz

Yes

NX2116ACMTR

MLPD-10L

600kHz

Yes

NX2116BCMTR

MLPD-10L

1MHz

Yes

NX2117CUTR

MSOP-10L

300kHz

Yes

NX2117ACUTR

MSOP-10L

600kHz

Yes

Figure 1 - Typical application of 2116

C5

1uF

Cin

Vin1

+12V

D1

M1

M2

L1 1uH

C2

1.5nF

C7

0.1uF

R2

16k

17.4k

R4

20k

R1

33pF

C1

68k

R5

12.4k

R6

Vcc

BST

Fb

Comp

SW

Hdrv

Ldrv

4

2

1

10

3

7

8

EN

6

C4

1uF

10

R3

+1.8V,9A

Vout

270uF,18mohm

2x (220uF,12mohm)

Co

Gnd

11

L2 1uH

C3

39uF

OFF

ON

2N3904

10k

R8

R7

10k

C8

1nF

2.61k

R9

Pgood

1k

R10

+5V

5

OCP

9

3.7k

R11

Vin2

+5V

MBR0530T1

Pb Free Product