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NX2147
SINGLE CHANNEL MOBILE PWM CONTROLLER WITH
DYNAMIC VOLTAGE ADJUSTMENT
PRODUCTION DATA SHEET Pb Free Product
FEATURES
DESCRIPTION
Output voltage can be dynamically changed
Internal Boost Schottky Diode
Ultrasonic mode operation available
Bus voltage operation from 4.5V to 22
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
The NX2147 controller IC is a step down switching con- n
troller with ability to dynamically adjust the output volt- n
age designed for applications such as Graphic Proces- n
sor Core voltage in Notebook PC products. It allows n
this by adjusting the reference input of the PWM n
comprator as oppose to the traditional method of feedback adjustment. This device has three mode of opera- n
tions; a) Constant ON Time Synchronous Mode, b) Non
Synchronous PFM mode or c) Ultrasonic PFM mode of n
operation. When selected in Non Synchronous mode,
the device automatically disables the synchronous
MOSFET in order to improve efficiency at light load. n
This device provides excellent dynamic response and n
nearly constant frequency for operation from 4.5V to n
22V of input voltage operation. Other features of the n
device are; internal logic level signal MOSFETs for output dynamic voltage adjustment, internal boost schotcky n
diode, less than 1uA VIN shutdown current, adjustable n
current limiting using lower MOSFET Rds-On and feed- n
back UVLO followed by latchdown, overvoltage protection , internal digital soft start and soft stop shutdown n
using and internal 20 ohm MOSFET pull down.
9
5V
10
1u
2
PVCC
TON
APPLICATIONS
Notebook PCs and Desknotes
Tablet PCs/Slates
On board DC to DC such as
12V to 3.3V, 2.5V or 1.8V
Hand-held portable instruments
TYPICAL APPLICATION
1MEG
16
VIN 7V~22V
1n
VCC
2x10uF
1u
14
ENSW
/MODE
GPIO0
6
GPIO1
NX 2 1 4 7
15
10 VREF_OC
100k
88.7k
10n
200k
4
634k
5
D1
D0
SW 11
LDRV 8
PGND
3 VP
0.1u
HDRV 12
BST 13
VOUT
FDS6294
2.2
1u
1uH
FDS6676AS
GPIO0 GPIO1 VOUT(V)
1
1
1.17
0
1
1.09
1
0
0.95
0
0.9
0
Vout (see table above) /12A
2R5TPE330MC
330uF
LOAD
7
1
AGND
6
Figure1 - Typical application of NX2147
ORDERING INFORMATION
Device
NX2147CMTR
Rev. 1.6
Rev. 1.9
03/09/09
06/13/12
Temperature
-10 o C to 100 o C
Package
3X3 MLPQ-16L
Pb-Free
Yes
1
NX2147
ABSOLUTE MAXIMUM RATINGS
VCC,PVCC to GND & BST to S W voltage ............ -0.3V to 6.5V
VIN,TON to GND .................................................. -0.3V to 28V
HDRV to S W Voltage .......................................... -0.3V to 6.5V
SW to GND ......................................................... -2V to 30V
All other pins ........................................................ VCC+0.3V
Storage Temperature Range ..................................-65 oC to 150 oC
Operating Junction Temperature Range .................-40 oC to 150 oC
ESD Susceptibility ............................................... 2kV
CAUTION: Stresses above those listed in "ABSOLUTE MAXIMUM R ATINGS", may cause permanent
damage to the device. This is a stress only rating and operation of the device at these or any other conditions
above those indicated in the operational sections of this specification is not implied.
PACKAGE INFORMATION
TON
ENSW/MODE
GPIO0
BST
3x3 16-LEAD PLASTIC MLPQ
16
15
14
13
θ JA ≈ 46o C/W
12 HDRV
VOUT 1
D1
4
10 VREF_OC
9 PVCC
5
6
7
8
LDRV
3
PGND
VP
11 SW
17(PAD)
AGND
GPIO1
2
D0
VCC
ELECTRICAL SPECIFICATIONS
Unless otherwise specified, these specifications apply over Vcc =5 V, VIN=15V and T A =25oC, unless otherwise
specified.
PARAMETER
SYM
Test Condition
Min
TYP
MAX
Units
22
V
uA
5.5
V
VIN
Recommended voltage range
Shut down current
VCC,PVCC Supply
Input voltage range
Operating quiescent current
Shut down current
Rev. 1.6
Rev. 1.9
03/09/09
06/13/12
4.5
ENSW=GND
Vcc
1
4.5
No switching, ENSW=5V
ENSW=GND
1.6
1
mA
uA
2
NX2147
PARAMETER
VCC UVLO
Under-voltage Lockout
threshold
Falling VCC threshold
ON and OFF time
SYM
Test Condition
Min
VCC _UVLO
TON operating current
VIN=15V, Rton=1Mohm
VIN=9V,VP=VOUT=0.75V,Rt
on=499k
ON -time
Minimum off time
VREF_OC voltage
VREF_OC voltage
Line regulation
OUTPUT voltage
Output range
VOUT shut down discharge
resistance
VCC from 4 to 5.5
380
2.475
-2
ENSW/MODE=GND
Low Side Driver
(CL=3300pF)
Output Impedance, Sourcing
Current
Output Impedance, Sinking
Current
Rise Time
Fall Time
Deadband Time
Over temperature
Threshold
Hysteresis
Rev. 1.6
Rev. 1.9
03/09/09
06/13/12
MAX
Units
4.1
3.9
V
V
15
uA
390
590
2.5
0.75
Soft start time
GPIO threshold
Output high
Output low
DO,D1 internal pull down
MOSFET
impedance
SW zero cross comparator
Offset voltage
High Side Driver
(CL=3300pF)
Output Impedance , Sourcing
Current
Output Impedance , Sinking
N
Current
Rise Time
Fall Time
Deadband Time
TYP
800
ns
ns
2.525
2
V
%
3.3
V
30
ohm
1.5
ms
2
0
5
0.8
V
V
13
mohm
5
mV
R source(Hdrv)
I=200mA
1.5
ohm
R sink (Hdrv)
I=200mA
1.5
ohm
THdrv(Rise)
10% to 90%
THdrv(Fall)
90% to 10%
Tdead(L to Ldrv going Low to Hdrv going
H)
High, 10% to 10%
50
50
30
ns
ns
ns
R source(Ldrv)
I=200mA
1.5
ohm
Rsink(Ldrv)
I=200mA
0.5
ohm
50
50
10
ns
ns
ns
TLdrv(Rise)
10% to 90%
TLdrv(Fall)
90% to 10%
Tdead(H to SW going Low to Ldrv going
L)
High, 10% to 10%
155
15
o
C
C
o
3
NX2147
PARAMETER
ENSW/MODE threshold and
bias current
SYM
Test Condition
PFM/Non Synchronous Mode
Ultrasonic Mode
Synchronous Mode
Shutdown mode
Input bias current
Under voltage protection
Under voltage trigger point
Over voltage protection
Over voltage tripp point
Internal Schottky Diode
Forward voltage drop
Rev. 1.6
Rev. 1.9
03/09/09
06/13/12
Leave it open or use limits in
spec
Min
TYP
80%
VCC
60%
VCC
MAX
VCC+0
.3V
80%
VCC
60%
VCC
0.8
V
V
ENSW/MODE=VCC
1
V
V
uA
ENSW/MODE=GND
-1
uA
70
%VP
125
%VP
500
mV
forward current=50mA
2
0
Units
4
NX2147
PIN DESCRIPTIONS
PIN NUMBER PIN SYMBOL
PIN DESCRIPTION
This pin is directly connected to the output of the switching regulator and
senses the VOUT voltage. An internal MOSFET with 20ohms rdson discharges the output during turn off.
1
VOUT
2
VCC
3
VP
This pin is connected via resistor divider to VREF_OC pin to set the output
DC voltage from 0.5V to VREF 2.5 V.
4
D1
This pin is a drain of an internal signal MOSFE T. When it is connected via
resistor to the VP pin,and the GPIO0 pin is set lo w, it reduces the VP
voltage by paralleling this resistor to the fixed resistor from VP to GND.
5
D0
This pin is a drain of an internal signal MOSFE T. When it is connected via
resistor to the VP pin,and the GPIO_1 pin is set lo w, it reduces the VP
voltage by paralleling this resistor to the fixed resistor from VP to GND.
6
GPIO1
A logic level input signal that controls the D1 pin. A low signal turns the
internal D1 MOSFET on and a High turns it off.
7
PGND
Power ground.
8
LDRV
Low side gate driver output.
9
PVCC
Provide the voltage supply to the lower MOSFET drivers. Place a high
frequency decoupling capacitor 1uF X5R to this pin.
10
VREF_OC
11
SW
12
HDRV
13
BST
14
GPIO0
A logic level input signal that controls the D0 pin. A low signal turns the
internal D0 MOSFET on and a High turns it off.
15
ENSW/
MODE
Switching converter enable input. Connect to VCC for PFM/Non synchronous
mode, connected to an external resistor divider equals to 70%VCC for ultrasonic, connected to GND for shutdown mode, floating or connected to 2V for
the synchronous mode.
16
TON
VIN sensing input. A resistor connects from this pin to VIN will set the frequency. A 1nF capacitor from this pin to GND is recommended to ensure the
proper operation.
17
PAD
Analog ground.
Rev. 1.6
Rev. 1.9
03/09/09
06/13/12
This pin supplies the internal 5V bias circuit. A 1uF X7R ceramic capacitor is
placed as close as possible to this pin and ground pin.
Reference output voltage. A resistor divider from this pin to VP pin sets the
output voltage. The total resistance from this pin to GND also sets the OCP
threshold voltage. Note that when GPIO0 and GPIO1 pins are high the
reference divider is at its highest voltage. The nominal voltage of Vref is
2.5V.
This pin is connected to source of high side FE Ts and provide return path for
the high side driver. It is also the input of zero current sensing comparato r.
High side gate driver output.
This pin supplies voltage to high side FET drive r. A high freq 1uF X7R
ceramic capacitor and 2.2ohm resistor in series are recommended to be
placed as close as possible to and connected to this pin and S W pin.
5
NX2147
BLOCK DIAGRAM
VCC(2)
Bias
TON(16)
VIN
4.3/4.1
ON time
pulse
genearation
VOUT
Disable_B
POR
Thermal
shutdown
start
HDRV(12)
FET Driver
HD_IN
Q
SW(11)
1.8V
5V
PVCC(9)
VREF_OC(10)
VREF
R1
VIN
ODB
HD
R
S
BST(13)
LDRV(8)
Mini offtime
400ns
OCP_COMP
VP(3)
PGND(7)
R2
start
POR
FBUVLO_latch
soft start
ENSW
/MODE(15)
HD
VCC
1M
1M
Disable
MODE
SELECTION
8k
PFM_nonultrasonic
Sync
VREF_OC
R1+R2
VOUT
1.25*Vref/0.7VREF OCP_COMP
OVP
AGND(PAD)
Diode
emulation
FBUVLO_latch
FB
0.7*Vref
VOUT(1)
DO(5)
VOUT
SCHIMTTER
TRIGGER
start
GPIO0(14)
D1(4)
SCHIMTTER
TRIGGER
GPIO1(6)
Figure 2 - Simplified block diagram of the NX2147
Rev. 1.6
Rev. 1.9
03/09/09
06/13/12
6
NX2147
TYPICAL APPLICATION
(VIN=7V to 22V, VOUT=1.09V/12A)
9
5V
R1
10
C1
1u
2
C2
1u
PVCC
TON
6
GPIO0
GPIO1
NX2147
14
10 VREF_OC
R2
100k
C3
0.1u
R3
88.7k
C4
10n
C5
1n
VCC
ENSW
15
/MODE
3 VP
R4
200k
4
D1
R5
634k
5
D0
R6
499k
16
HDRV 12
R8 2.2
BST 13
SW 11
VIN 7V~22V
CI1
2x10uF
M1
FDS6294
C6
1u
M2
LDRV 8
FDS6676AS
Lo
1uH
R7
10
C7
470p
Vout (see table below) /12A
CO1
2R5TPE330MC
330uF
LOAD
PGND 7
VOUT
1
AGND
6
VOUT TABLE:
GPIO0 GPIO1 VOUT(V)
1
1
1.17
0
1
1.09
1
0
0.95
0
0
0.9
Figure 3 - Demo board schematic
Rev. 1.6
Rev. 1.9
03/09/09
06/13/12
7
NX2147
Bill of Materials
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Rev. 1.6
Rev. 1.9
03/09/09
06/13/12
Quantity
2
1
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
CI1
CO1
C1,C2
C3,C6
C4
C5
C7
Lo
M1
M2
R1
R2
R3
R4
R5
R6
R7
R8
U1
Reference
Value
10uF/X5R/25V
2R5TPE330MC
1uF
0.1uF
10nF
1nF
470p
RL-8250-1.4-1R0M
FDS6294
FDS6676AS
10
100k
88.7k
200k
634k
499k
10
2.2
NX2147
Manufacture
SANYO
RENCO
FAIRCHILD
FAIRCHILD
NEXSEM INC.
8
NX2147
Demoboard waveforms
Fig.5 10A step response( CH1 VOUT AC 50mV/DIV,
CH4 Output current 5A/DIV)
Fig.6 Soft turn off(CH1 ENS W 2V/DIV, CH2 VOUT
0.5V/DIV)
Fig.7 D0=0, D1 from low to high(CH1 D0 2V/DI V,
CH2 VOUT 0.1V/DIV 0.8V OFFSE T, CH3 INDUCTOR CURRENT 5A/DIV, CH4 VP 0.1V/DIV 0.8V
OFFSET)
OUTPUT EFFICIENCY (%)
Fig.4 Start up( CH1 VOUT 1V/DI V, CH4 Output
current 5A/DIV)
95
OUTPUT EFFICIENCY (VIN=12V,VOUT=1.09V)
90
85
80
75
70
65
60
55
50
Fig.8 D1=0, D0 from low to high(CH1 D0 2V/DI V,
CH2 VOUT 0.1V/DIV 0.8V OFFSE T, CH3 INDUCTOR CURRENT 5A/DIV, CH4 VP 0.1V/DIV 0.8V
OFFSET)
Rev. 1.6
Rev. 1.9
03/09/09
06/13/12
10
100
1000
10000
OUTPUT CURRENT (mA)
Fig.9 Output efficiency
9
NX2147
MLPQ 16 PIN 3 x 3 PACKAGE OUTLINE DIMENSIONS
SYMBOL
NAME
A
A1
A3
B
D
D2
E
E2
e
L
M
Rev. 1.6
Rev. 1.9
03/09/09
06/13/12
Dimensions In Millimeters
MIN
0.700
0.000
0.180
2.950
1.600
2.950
1.600
0.325
0.203REF
0.50BSC
1.5REF
Dimensions In Inches
MAX
0.800
0.050
MIN
0.028
0.000
0.300
3.050
1.750
3.050
1.750
0.007
0.116
0.063
0.116
0.063
0.450
0.013
0.008REF
0.50BSC
0.059REF
MAX
0.031
0.002
0.012
0.120
0.069
0.120
0.069
0.018
10