NX2147 Datasheet, PDF (1/11 Pages) Microsemi Corporation – SINGLE CHANNEL MOBILE PWM CONTROLLER WITH DYNAMIC VOLTAGE ADJUSTMENT

NX2147
SINGLE CHANNEL MOBILE PWM CONTROLLER WITH
DYNAMIC VOLTAGE ADJUSTMENT
PRODUCTION DATA SHEET Pb Free Product
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
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comprator as oppose to the traditional method of feed-
back adjustment. This device has three mode of opera-
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tions; a) Constant ON Time Synchronous
Synchronous PFM mode or c) Ultrasonic
Mode, b) Non
PFM mode of
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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
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FEATURES
Output voltage can be dynamically changed
Internal Boost Schottky Diode
Ultrasonic mode operation available
Bus voltage operation from 4.5V to 24V
Less than 1uA VIN shutdown current with Enable
low
Excellent dynamic response with constant on time
control
Selectable between Synchronous CCM mode and
diode emulation mode to improve efficiency at
light load
Programmable switching frequency
Current limit and FB UVLO with latch off
Over voltage protection with latch off
Pb-free and RoHS compliant
device are; internal logic level signal MOSFETs for out-
APPLICATIONS
put dynamic voltage adjustment, internal boost schotcky _{n Notebook PCs and Desknotes}
diode, less than 1uA VIN shutdown current, adjustable _{n Tablet PCs/Slates}
current limiting using lower MOSFET Rds-On and feed- _{n On board DC to DC such as}
back UVLO followed by latchdown, overvoltage protec- _{12V to 3.3V, 2.5V or 1.8V}
tion , internal digital soft start and soft stop shutdown _{n Hand-held portable instruments}
using and internal 20 ohm MOSFET pull down.
TYPICAL APPLICATION
5V
9 _PVCC
16
1MEG
10
2 _VCC
TON
1n
VIN 7V~22V
1u
1u
2x10uF
GPIO0 GPIO1 VOUT(V)
1
1
1.17
15
ENSW
/MODE
HDRV ¹²
BST ^{13 2.2}
1u
FDS6294
0
1
1
0
0
0
1.09
0.95
0.9
14 _GPIO0
SW ¹¹
1uH
Vout (see table above) /12A
6 _GPIO1
10 _{VREF_OC}
LDRV ⁸
FDS6676AS
2R5TPE330MC
330uF
LOAD
100k
0.1u
88.7k
10n
3 _VP
200k
4
D1
634k
5
D0
AGND
6
PGND ⁷
VOUT ¹
Figure1 - Typical application of NX2147
ORDERING INFORMATION
Device
Temperature
Package
NX2147CMTR -10^o C to 100^o C 3X3 MLPQ-16L
Pb-Free
Yes
Rev. 1.6
03R/0e9v./019.8
1
12/28/09