NX2309 Datasheet, PDF (1/16 Pages) Microsemi Corporation – SINGLE SUPPLY 12V SYNCHRONOUS PWM CONTROLLER WITH NMOS LDO CONTROLLER

Evaluation board available.
NX2309
SINGLE SUPPLY 12V SYNCHRONOUS PWM CONTROLLER
WITH NMOS LDO CONTROLLER
PRELIMINARY DATA SHEET
Pb Free Product
DESCRIPTION
FEATURES
The NX2309 controller IC is a combination synchronous ^{n 12V PWM controller plus LDO controller}
Buck and LDO controller IC designed to convert single ^{n Fixed hiccup current limit by sensing Rdson of}
12V supply to low cost dual on board supply applica- ^MOSFET
tions. The synchronous controller is used for high cur- ^{n 12V high side and low side driver}
rent high efficiency step down DC to DC converter appli- ^{n Fixed internal 300kHz for switching controller}
cations while the LDO controller in conjunction with an ^{n Dual Independent Digital Soft Start Function}
external low cost N ch MOSFET can be used as a very ^{n Adaptive Deadband Control}
low drop out regulator in applications such as converting ^{n Shut Down switching via pulling down COMP pin}
3.3V to 2.5V output. Internal UVLO keeps both regula- ^{n Pb-free and RoHS compliant}
tors off until the supply voltage exceeds 9V where inde-
pendent internal digital soft starts get initiated to ramp
up both outputs.The switching section has fixed hiccup
current limit by sensing the Rdson of synchronous
MOSFET. The LDO controller has Feedback Under
n
n
n
Voltage Lock Out as a short circuit protection.Other fea-
tures includes: 12V gate drive capability , Adaptive dead
n
APPLICATIONS
PCI Graphic Card on board converters
Mother board On board DC to DC applications
On board Single Supply 12V DC to DC such as
12V to 3.3V, 2.5V or 1.8V
Set Top Box and LCD Display
band control.
TYPICAL APPLICATION
VOUT1
+1.8V
VOUT2
+1.2V/2A
R14 10
C9
47uF
M3
IRFR3706
C10 150pF
C8
150uF
25mohm
R8
5k
R9
10k
C12
1uF
VCC
LDO OUT
LDO FB
BST
HDRV
C13
200pF
COMP
R5
5.36k
C5
6.8nF
FB
GND
SW
LDRV
D1 MBR0530T1 _{L1 1uH}
C2
C3
C4
180uF
47uF
0.1uF M1
IRFR3709Z
L2 1.5uH
M2
IRFR3709Z
R2
1.43k
R3
10k
C6
2.7nF
VIN1
+12V
VOUT1
+1.8V/10A
C7
4SEPC560M
560uF,7mohm
R4
8k
Device
NX2309CUTR
NX2309CMTR
Figure1 - Typical application of NX2309
ORDERING INFORMATION
Temperature
0 to 70^oC
0 to 70^oC
Package
MSOP - 10L
MLPD - 10L
Frequency
300kHz
300kHz
Pb-Free
Yes
Yes
Rev. 2.0
1
12/19/05