Evaluation board available.
NX2601
DUAL SYNCHRONOUS PWM CONTROLLER WITH NMOS LDO
CONTROLLER & 5V BIAS REGULATOR
PRELIMINARY DATA SHEET
Pb Free Product
FEATURES
DESCRIPTION
n Two channel PWM with out of phase operation
The NX2601 controller IC is a triple controller with a dual
channel synchronous Buck controller IC and an LDO con-
troller designed for multiple converters such as PCIe
graphic card applications .The two synchronous PWM
controllers are 180 degree out of phase which reduces
the input ripple current, allowing to reduce the # of input
capacitors.Another main feature of the part is that it can
operate from single 12V supply while maintaining a regu-
lated 5V supply for the biasing and the internal drivers.
Other features of NX2601 are: programmable frequency
from 200kHz to 1MHz, independent digital soft start and
enable pins for each controller which allows for different
power sequencing, Adaptive driver provides optimized ef-
ficiency while maintain sufficient deadband, Vcc
undervoltage lock out and current limiting using an Rds-
on of the external MOSFET with HICCUP feature.
n Individual digital soft start for two PWM output
and LDO controller
n
n
Bus voltage operation from 2V to 25V
Hiccup Current limit by sensing Rdson of MOSFET
n Adjustable frequency up to 1Mhz per channel
n Adaptive deadband time
n Three enable pin available allows for independent
power sequencing
n MLPQ-32L package offers small size
n Pb-free and RoHS compliant
APPLICATIONS
n
n
n
PCI Graphic Card on board converters
Vddq Supply in mother board applications
On board DC to DC such as
12V to 3.3V, 2.5V or 1.8V
n
FPGA and Set Top Box Applications
TYPICAL APPLICATION
10
R11
+5V
C15
1uF
R12
5k
C17
68uF
5
23 C1
1uF
11
R13
1.65k
VCC
+5V
REG FB
PVCC1
VIN1
L1 1uH
47pF
C16
VIN1
+12V
D1
24
C3
100uF
C2
180uF
BST1
10
REG OUT
AUXVCC
LDO OUT
2N3904
M5
C4
5k
0.1uF
M1
9
8
VIN2
+3.3V
25
26
C24 1uF
R15
HDRV1
L2 0.78uH
C20
VOUT1
C18
150uF
SW1
+1.2V@15A
0
R1 10.5k
150pF
27
C7
VOUT3
+2.5V/2A
7
OCP1
LDO FB
ENLDO
2 x (2R5TPD680M6,680uF,6mohm)
R2
1.5k
R16
5k
R17
2.35k
R3
10.4k
22
21
C19
150uF
LDRV1
R18
1.5k
M2
C6
2.7nF
PGND1
Fb1
29
28
3
R5 5k
C22
OFF R25
10k
8.2nF C5
220pF
+5V
R4
20.8k
R19
1.25k
2N3904
Comp1
PVCC2
C25
1uF
ON
R26
10k
18 C8
1uF
R20
6.8k
D2
1
ENSW1
VIN1
17
C9
180uF
BST2
R21
C11
0.1uF
1.25k
M3
L4 1.5uH
16
15
HDRV2
OFF R27
10k
2N3904
VOUT2
2
6
ON
ENSW2
RT
R28
10k
SW2
+1.8V/10A
R6
14
6k
C14
OCP2
3 x (4TPE150M,150uF,18mohm)
R7
820
R8
8.7k
M4
19
LDRV2
20
12
C13
PGND2
Fb2
R24
C21
62k
3.3nF
30
31
VP
VREF
C12
R10
R9
6.97k
13
1nF
Comp2
GND
5k
10nF
4
220pF
C23
Figure1 - Typical application of 2601
PATENT PENDING
ORDERING INFORMATION
Device
NX2601CMTR
Temperature
0 to 70oC
Package
MLPQ-32L
Frequency
Pb-Free
Yes
200kHz to 1MHz
Rev. 2.3
12/01/06
1