NX2158ds.pdf

NX2158
PWM BOOST CONTROLLER
PRODUCTION DATA SHEET
Pb Free Product
FEATURES
DESCRIPTION
The NX2158 controller IC is a boost controller IC designed for step up DC to DC converter applications. The
NX2158 operates at programmable frequency from
200kHz to 2MHz and employs cycle by cycle current
limiting by sensing the Rdson of NMOSFET.
Other features of the device are: thermal shutdown,
adaptive deadband control, internal digital soft start, VCC
UVLO and Shutdown capability via the ENBUS pin.
n Single Supply Voltage fom 3V to 5.5V
n Programmable Frequency up to 2MHz
n Internal Digital Soft Start Function
n Cycle by Cycle Current Limit by Sensing Rdson of
NMOSFET
n Pb-free and RoHS compliant
APPLICATIONS
n
USB 3.0 3.3V to 5V conversion
TYPICAL APPLICATION
2.2uH
VIN 3.3V
VOUT 5V
22uF,X5R
2*22uF
1uF
14k
10
VCC LDrv
1uF
10k
PGOOD
SW
HDrv
PGND BST
308k
68p
FB
PGOOD ENBUS RT AGND OCP COMP
15pF
22k
10k
59k
EN
20k
1nF
Figure1 - Typical application of NX2158
ORDERING INFORMATION
Device
NX2158CMTR
Temperature
0 to 70o C
Package
Frequency
3X3 MLPQ-16L 200kHz to 2MHz
Pb-Free
Yes
Package Marking : NX2158XXX XXX is date code. For example, 935 means that this NX2158 is
packaged in the 35th week of 2009
Rev.1.2
12/30/09
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
1
NX2158
ABSOLUTE MAXIMUM RATINGS(NOTE1)
VCC to GND .................................................. 6.5V
BST to GND Voltage ...................................... 6.5V
VIN to GND Voltage ........................................ 6.5V
SW to GND .................................................... -2V to 6.5V
All other pins .................................................. -0.3V to 6.5V
Storage Temperature Range ............................. -65oC to 150oC
Operating Junction Temperature Range ............. -40oC to 125oC
NOTE1: Stresses above those listed in "ABSOLUTE MAXIMUM RATINGS", 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
16-LEAD PLASTIC 3X3 MLPQ
NC
OCP
SW
NC
θ JA ≈ 46o C/W
16
15
14
13
HDRV 1
12 FB
BST 2
11 COMP
17
PAD
PGND 3
10 AGND
9 RT
5
6
7
8
VCC
NC
ENBUS
PGOOD
LDRV 4
ELECTRICAL SPECIFICATIONS
Unless otherwise specified, these specifications apply over VCC=3.3V, VENBUS=1.5V, VBST=5V, T A = 25oC. Low duty
cycle pulse testing is used which keeps junction and case temperatures equal to the ambient temperature.
PARAMETER
Reference Voltage
SYM
Ref Voltage
Ref Voltage line regulation
VREF
Supply Voltage(VCC)
VCC Voltage Range
Input Voltage Current(Static)
Input Voltage Current
(Dynamic)
Under Voltage Lockout
VCC-Threshold
VCC-Hysteresis
Rev.1.2
12/30/09
Test Condition
Min
TYP
MAX
Units
0.793
0.8
0.7
0.808
1
V
%
VCC=3V to 5.5V
Vin
V
No switching,ENBUS=0V
COMP=2.4V
VCC _UVLO VCC Rising
VCC _Hyst
VCC Falling
3
mA
3.5
mA
2.6
2.8
3
V
0.1
0.2
0.355
V
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
2
NX2158
PARAMETER
SYM
Test Condition
M in
TYP
MAX
Un its
1
0.05
1.2
0.1
1.4
0.15
V
V
ENBUS
ENBUS threshold
ENBUS Hysteresis
SS
Soft Start time
Oscillator (Rt)
Frequency
Ram p-Amplitude Voltage
Tss
Rt=44k
FS
Rt=44k
550
Rt=44k
0.4
60
V RAMP
LDRV Max Duty Cycle
HDRV Min Controlable On Time
Error Amplifiers
Transconductance
Input Bias Current
Com p SD Threshold
High Side Driver(CL =2200pF)
Output Impedance , Sourcing
Output Impedance , Sinking
1.6
1500
640
0.5
70
mS
720
0.58
80
kHz
V
%
250
nS
2500
100
0.3
umho
nA
V
1800
Ib
R source(Hdrv)
I=200mA
1.9
ohm
R sink(Hdrv)
I=200mA
1.7
ohm
ns
ns
ns
Rise Time
Fall T ime
Deadband Time
Low Side Driver (CL =2200pF)
THdrv(Rise)
THdrv(Fall)
Tdead(L to
Ldrv going Low to Hdrv
14
17
30
Output Impedance, Sourcing
Output Impedance, Sinking
Current
Rise Time
Fall T ime
Deadband Time
Rsource (Ldrv)
R sink (Ldrv)
I=200mA
I=200mA
1.9
1
ohm
ohm
13
12
10
ns
ns
ns
T Ldrv(Rise)
TLdrv(Fall)
Tdead(H to
SW going Low to Ldrv
L)
going High, 10% to 10%
OCP
OCP current
Over temperature
Threshold
Hysteresis
PGOOD
Pgood high rising threshold
Power good hysteresis
Rev.1.2
12/30/09
30
37
50
o
150
20
78
90
5
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
uA
o
95
C
C
% Vref
%
3
NX2158
PIN DESCRIPTIONS
PIN #
VCC
PIN DESCRIPTION
Voltage supply for the low side fet driver and internal logic circuit. A high
frequency 1uF ceramic capacitor must be connected from this pin to the GND
pin as close as possible.
7
ENBUS
Enable pin for the controller.
12
FB
This pin is the error amplifier inverting input.
11
COMP
This pin is the output of the error amplifier and together with FB pin is used to
compensate the voltage control feedback loop. This pin is also used as a shut
down pin. When this pin is pulled below 0.3V, both drivers are turned off and
internal soft start is reset.
2
BST
This pin supplies voltage to the high side driver. A high frequency
ceramic capacitor of 0.1 to 1 uF must be connected from this pin to ground.
15
OCP
An internal current source is flown to the OCP resistor sets the OCP voltage
across the Rdson of the low side MOSFET. Current limit point is this voltage
divided by the Rds-on.
14
SW
This pin is used by driver circuit and also sensing the RDSON of NMOSFET.
1
HDRV
PMOS MOSFET gate driver.
3
PGND
Power ground.
10
AGND
Analog ground
4
LDRV
NMOSFET gate driver.
7
RT
Oscillator's frequency can be set by using an external resistor from this pin to
GND.
8
PGOOD
Power good indicator.
17
PAD
PAD should be connected to ground.
13,16
NC
Not used.
5
Rev.1.2
12/30/09
PIN SYMBOL
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
4
NX2158
BLOCK DIAGRAM
ENBUS
FB
PGOOD
SS_finished
0.9*0.8V
VCC
1.25V
Bias
Generator
1.2V
0.8V
UVLO
BST
POR
START
HDRV
COMP
0.3V
RT
OC
OVP
START 0.8V
Latch
VCC
PWM
OSC
Digital
start Up
Driver
Logic
ramp
S
R
Q
Thermal
Shutdown
LDRV
FB
0.6V
CLAMP
COMP
1.3V
CLAMP
LDRV
START
SW
OCP
GND
START
VCC
Figure 2 - Simplified block diagram of the NX2158
Rev.1.2
12/30/09
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
5