ONSEMI NCP1522ASNT1G

NCP1522
3.0 MHz, 600 mA,
High−Efficiency, Low
Quiescent Current,
Adjustable Output Voltage
Step−Down Converter
The NCP1522 step−down PWM DC−DC converter is optimized
for portable applications powered from one cell Li−ion or three cell
Alkaline/NiCd/NiMH batteries. The device is available in an
adjustable output voltage from 0.9 V to 3.3 V. It uses synchronous
rectification to increase efficiency and reduce external part count.
The device also has a built−in 3.0 MHz (nominal) oscillator which
reduces component size by allowing a small inductor and capacitors.
Automatic switching PWM/PFM mode offers improved system
efficiency.
Finally, it includes an integrated soft−start, cycle−by−cycle current
limiting, and thermal shutdown protection. The NCP1522 is
available in a space saving, low profile TSOP5 package.
Features
• 93.8% of Efficiency for 3.3 V Output and 4.5 V Input and 120 mA
•
•
•
•
•
•
•
•
•
•
Load Current
Sources up to 600 mA
3.0 MHz Switching Frequency
Adjustable Output Voltage from 0.9 V to 3.3 V
60 mA Quiescent Current (Typ)
Synchronous Rectification for Higher Efficiency
2.7 V to 5.5 V Input Voltage Range
Thermal Limit Protection
Shutdown Current Consumption of 0.3 mA
Short Circuit Protection
This is a Pb−Free Device
L
1
VIN
2
GND
LX
EN
1
DBRAYWG
G
1
A
= Assembly Location
Y
= Year
W
= Work Week
G
= Pb−Free Package
(Note: Microdot may be in either location)
VIN
1
GND
2
EN
3
5
LX
4 FB
ORDERING INFORMATION
Device
NCP1522ASNT1G
Package
Shipping
TSOP−5 3000/Tape & Reel
(Pb−Free)
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specification
Brochure, BRD8011/D.
VOUT
COUT
R1
3
5
5
CIN
OFF ON
5
TSOP−5
ASN SUFFIX
CASE 483
(Top View)
Cellular Phones, Smart Phones and PDAs
MP3 Players and Portable Audio Systems
Wireless and DSL Modems
Portable Equipment
USB Powered Devices
Digital Still/Video Cameras
VIN
MARKING
DIAGRAM
PIN CONNECTIONS
Typical Applications
•
•
•
•
•
•
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FB
Cff
4
R2
Figure 1. Typical Application
© Semiconductor Components Industries, LLC, 2006
August, 2006 − Rev. 3
1
Publication Order Number:
NCP1522/D
NCP1522
100
Eff (%)
90
80
70
Vout = 3.3 V
Vin = 4.5 V
TA = 25°C
60
50
0
100
200
300
Iout (mA)
400
500
600
Figure 2. Efficiency vs. Output Current
Q1
Vbattery
Q2
VIN
1
LX
5
PWM/BURST
CONTROL
2.2 mH
4.7 mF
4.7 mF
GND
2
Enable
EN
3
R1
ILIMIT
LOGIC
CONTROL
& THERMAL
SHUTDOWN
FB
4
REFERENCE
VOLTAGE
R2
Figure 3. Simplified Block Diagram
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2
18 pF
NCP1522
PIN FUNCTION DESCRIPTION
Pin No.
Symbol
Function
Description
1
VIN
Analog Input
2
GND
Analog/Power Ground
3
EN
Digital Input
Enable for Switching Regulator. This pin is active high. Do not float this pin.
4
FB
Analog Input
Feedback voltage from the output of the power supply. This is the input to the
error amplifier.
5
LX
Analog Output
Connection from Power MOSFETs to the Inductor. For one option, an output
discharge circuit sinks current from this pin.
Power Supply Input for Analog VCC.
Ground connection for the NFET Power Stage and the Analog Sections of the IC.
MAXIMUM RATINGS
Symbol
Value
Unit
Minimum Voltage All Pins
Rating
Vmin
−0.3
V
Maximum Voltage All Pins (Note 1)
Vmax
7.0
V
Maximum Voltage Enable, FB, LX
Vmax
VIN + 0.3
V
Thermal Resistance, Junction −to−Air
RqJA
200
_C/W
Operating Ambient Temperature Range
TA
−40 to 85
_C
Storage Temperature Range
Tstg
−55 to 150
_C
Junction Operating Temperature
Tj
−40 to 125
_C
Latch−up Current Maximum Rating (TA = 85°C) (Note 2)
Lu
+/−100
mA
2.0
200
kV
V
ESD Withstand Voltage (Note 3)
Human Body Model
Machine Model
Vesd
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
1. According to JEDEC standard JESD22−A108B.
2. Latchup current maximum rating per JEDEC standard: JESD78.
3. This device series contains ESD protection and exceeds the following tests:
Human Body Model (HBM) per JEDEC standard: JESD22−A114.
Machine Model (MM) per JEDEC standard: JESD22−A115.
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NCP1522
ELECTRICAL CHARACTERISTICS (Typical values are referenced to TA = +25°C, Min and Max values are referenced −40°C to
+85°C ambient temperature, unless otherwise noted, operating conditions VIN = 3.6 V, VOUT = 1.8 V, unless otherwise noted.)
Characteristic
Symbol
Min
Typ
Max
Unit
VIN
2.7
−
5.5
V
Undervoltage Lockout (VIN Falling)
VUVLO
2.3
2.5
2.6
V
Quiescent Current (PFM No Load)
Iq
−
60
95
mA
Standby Current, EN Low
Istb
−
0.3
1.2
mA
Oscillator Frequency
Fosc
2.400
3.0
3.600
MHz
Peak Inductor Current
ILIM
−
1200
−
mA
Feedback Reference Voltage
Vref
−
0.6
−
V
FB Pin Tolerance
VFBtol
−3.0
−
3.0
%
Reference Voltage Line Regulation
DVFB
−
0.1
−
%
Output Voltage Accuracy (Note 4)
VOUT
−3%
Vnom
+3%
V
Minimum Output Voltage
VOUT
−
0.9
−
V
Maximum Output Voltage
VOUT
−
3.3
−
V
DVOUT
−
0.1
−
%
−
−
0.0005
0.001
−
−
%/mA
%/mA
VOUT
−
35
−
mV
−
−
−
100
%
RLxH
−
300
−
mW
N−Ch On−Resistance
RLxL
−
300
−
mW
P−Ch Leakage Current
ILeakH
−
0.05
−
mA
N−Ch Leakage Current
ILeakL
−
0.01
−
mA
Enable Pin High
VENH
1.2
−
−
V
Enable Pin Low
VENL
−
−
0.4
V
EN << H >> Input Current, EN = 3.6 V
IENH
−
2.0
−
mA
Soft−Start Time
Tstart
−
350
500
ms
Thermal Shutdown Threshold
TSD
−
160
−
°C
Thermal Shutdown Hysteresis
TSDH
−
25
−
°C
Input Voltage Range
Output Voltage Line Regulation (Vin = 2.7–5.5)
Io = 200 mA
Voltage Load Regulation
(IO = 200 mA to 300 mA)
(IO = 200 mA to 600 mA)
VLOADREG
Load Transient Response (300 mA to 600 mA Load Step, Trise 1.0 ms)
Duty Cycle
P−Ch On−Resistance
4. The overall output voltage tolerance depends upon the accuracy of the external resistor (R1, R2).
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100
100
90
90
QUIESCENT CURRENT (mA)
QUIESCENT CURRENT (mA)
NCP1522
80
70
60
50
40
30
20
EN = VIN
10
IOUT = 0 mA
0
2.7
3.2
3.7
4.2
4.7
5.2
80
70
VIN = 5.5 V
60
50
VIN = 2.7 V
40
30
20
10
0
−40
5.7
−20
VIN, INPUT VOLTAGE (V)
0
20
40
60
80
100
TEMPERATURE (°C)
Figure 4. Quiescent Current vs. Supply Voltage
Figure 5. Quiescent Current vs. Temperature
100
1.0
IOUT = 0 mA
0.8
95
EFFICIENCY (%)
SHUTDOWN CURRENT (mA)
EN = 0 V
0.6
0.4
0.2
TA = −40°C
90
TA = 25°C
85
80
TA = 85°C
75
70
0
2.7
3.2
3.7
4.2
4.7
0
100
VIN, INPUT VOLTAGE (V)
200
300
400
600
IOUT, OUTPUT CURRENT (mA)
Figure 7. Efficiency vs. Output Current
(VOUT = 1.8 V, VIN = 3.6 V)
Figure 6. Shutdown Current vs. Supply Voltage
100
100
90
TA = −40°C
TA = −40°C
EFFICIENCY (%)
EFFICIENCY (%)
500
TA = 25°C
80
70
90
TA = 25°C
TA = 85°C
80
60
TA = 85°C
70
50
0
100
200
300
400
500
600
0
IOUT, OUTPUT CURRENT (mA)
100
200
300
400
500
IOUT, OUTPUT CURRENT (mA)
Figure 9. Efficiency vs. Output Current
(VOUT = 3.3 V, VIN = 4.5 V)
Figure 8. Efficiency vs. Output Current
(VOUT = 0.9 V, VIN = 3.6 V)
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5
600
100
3.6
90
3.4
FREQUENCY (MHz)
EFFICIENCY (%)
NCP1522
80
VOUT = 0.9 V
70
VOUT = 1.8 V
60
VOUT = 3.3 V
50
3.2
IOUT = 300 mA
3.0
IOUT = 600 mA
2.8
2.6
40
30
0
100
200
300
400
500
2.4
2.7
600
3.2
3.7
3.6
LOAD REGULATION (%)
FREQUENCY (MHz)
3.4
VIN = 5.5 V
3.0
VIN = 3.6 V
2.6
IOUT = 300 mA
2.4
−40
−20
0
20
40
5.2
5.7
Figure 11. Frequency vs. Input Voltage
Figure 10. Efficiency vs. Output Current
(VIN = 4.0 V)
2.8
4.7
VIN, INPUT VOLTAGE (V)
IOUT, OUTPUT CURRENT (mA)
3.2
4.2
60
80
3.0
2.5
2.0
1.5
1.0
0.5
0.0
VOUT = 0.9 V
VOUT = 1.8 V
VOUT = 3.3 V
−0.5
−1.0
−1.5
−2.0
−2.5
−3.0
100
0
100
TEMPERATURE (°C)
200
300
400
500
600
700
IOUT, OUTPUT CURRENT (mA)
Figure 13. Load Regulation
Figure 12. Frequency vs. Temperature
2.0
300
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE (V)
VOUT = 1.8 V
1.5
1.0
0.5
0.2
0.4
0.6
0.8
1.0
1.2
1.4
TA = 25°C
200
150
100
50
0
2.7
0.0
0
250
VIN, ENABLE INPUT VOLTAGE (V)
3.2
3.7
4.2
4.7
5.2
VIN, INPUT VOLTAGE (V)
Figure 14. Output Voltage vs. Enable Input Pin
Voltage
Figure 15. PFM/PWM Threshold vs. Input
Voltage
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6
5.7
NCP1522
2.0
2.0
1.5
1.0
OUTPUT VOLTAGE (%)
IOUT = 100 mA
0.5
IOUT = 300 mA
0.0
−0.5
IOUT = 600 mA
−1.0
−1.5
1.0
IOUT = 100 mA
0.5
IOUT = 300 mA
0.0
−0.5
IOUT = 600 mA
−1.0
−1.5
VIN = 3.6 V
−2.0
−50
VIN = 3.6 V
0
50
100
−2.0
−50
150
0
TEMPERATURE (°C)
50
Figure 17. Output Voltage Accuracy
(VOUT = 1.8 V)
2.0
1.5
1.0
0.5
IOUT = 300 mA
IOUT = 100 mA
0.0
IOUT = 600 mA
−0.5
−1.0
−1.5
VIN = 4.0 V
−2.0
−50
100
TEMPERATURE (°C)
Figure 16. Output Voltage Accuracy
(VOUT = 0.9 V)
OUTPUT VOLTAGE (%)
OUTPUT VOLTAGE (%)
1.5
0
50
100
TEMPERATURE (°C)
Figure 18. Output Voltage Accuracy
(VOUT = 3.3 V)
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150
150
NCP1522
IOUT
IOUT
200 mA/Div
200 mA/Div
VOUT
VOUT
20 mV/Div
20 mV/Div
10 ms/Div
10 ms/Div
Figure 20. Load Transient Response in PWM
Operation (VIN = 3.6 V)
Figure 19. Load Transient Response in PWM
Operation (VIN = 3.6 V)
2.5 ms/Div
EN
2 V/Div
ILX
500 mA/Div
VOUT
500 mV/Div
VOUT
500 mV/Div
100 ms/Div
Figure 21. Soft Start Time (VIN = 3.6 V)
Figure 22. Short Circuit Protection (VIN = 3.6 V)
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NCP1522
OPERATION DESCRIPTION
Overview
The NCP1522 uses a constant frequency, voltage mode
step−down architecture. Both the main (P−Channel
MOSFET) and synchronous (N−Channel MOSFET)
switches are internal.
It delivers a constant voltage from either a single Li−Ion
or three cell NiMH/NiCd battery to portable devices such
as cell phones and PDA. The output voltage is set by
external resistor divider. The NCP1522 sources at least
600 mA depending on external components chosen.
The NCP1522 works with two modes of operation; PWM
depending on the current required. The device operates in
PWM/PFM mode at load currents of approximately 80 mA
or higher, having voltage tolerance of "3% with 90%
efficiency or better. Lighter load currents cause the device
to automatically switch into PFM mode for reduced current
consumption (IQ = 60 mA typ) and extended battery life.
Additional features include soft−start, undervoltage
protection, current overload protection, and thermal
shutdown protection. As shown in Figure 1, only six
external components are required for implementation. The
part uses an internal reference voltage of 0.6 V. It is
recommended to keep the part in shutdown until the input
voltage is 2.7 V or higher.
125 ns/div
Figure 23. PWM Switching Waveform
(Vin = 3.6 V, Vout = 1.8 V, Iout = 300 mA)
PFM Operating Mode
Under light load conditions, the NCP1522 enters in low
current PFM mode operation to reduce power
consumption. The output regulation is implemented by
pulse frequency modulation. If the output voltage drops
below the threshold of PFM comparator (typically
Vnom−2%), a new cycle will be initiated by the PFM
comparator to turn on the switch Q1. Q1 remains ON until
the peak inductor current reaches 200 mA (nom). Then
ILIM comparator goes high to switch off Q1. After a short
dead time delay, switch rectifier Q2 is turned ON. The
negative current detector (NCD) will detect when the
inductor current drops below zero and sends the signal to
turn off Q2. The output voltage continues to decrease
through discharging the output capacitor. When the output
voltage falls below the threshold of the PFM comparator,
a new cycle starts immediately.
PWM Operating Mode
In this mode, the output voltage of the NCP1522 is
regulated by modulating the on−time pulse width of the
main switch Q1 at a fixed frequency of 3.0 MHz. The
switching of the PMOS Q1 is controlled by a flip−flop
driven by the internal oscillator and a comparator that
compares the error signal from an error amplifier with the
PWM ramp. At the beginning of each cycle, the main
switch Q1 is turned ON by the rising edge of the internal
oscillator clock. The inductor current ramps up until the
sum of the current sense signal and compensation ramp
becomes higher than the error voltage amplifier. Once this
has occurred, the PWM comparator resets the flip−flop, Q1
is turned OFF and the synchronous switch Q2 is turned ON.
Q2 replaces the external Schottky diode to reduce the
conduction loss and improve the efficiency. To avoid
overall power loss, a certain amount of dead time is
introduced to ensure Q1 is completely turned OFF before
Q2 is being turned ON.
5 ms/div
Figure 24. PFM Mode Switching Waveform
(Vin = 3.6 V, Vout = 1.8 V, Iout = 30 mA)
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NCP1522
consumption will be 0.3 mA (typical value). Applying a
voltage above 1.2 V to EN pin will enable the device for
normal operation. The device will go through soft−start to
normal operation, however, the EN pin should be tied low
while the input voltage on VIN pin is rising up.
Cycle−by−Cycle Current Limitation
From the block diagram (Figure 3), an ILIM comparator
is used to realize cycle−by−cycle current limit protection.
The comparator compares the LX pin voltage with the
reference voltage, which is biased by a constant current. If
the inductor current reaches the limit, the ILIM comparator
detects the LX voltage falling below the reference voltage
and releases the signal to turn off the switch Q1. The
cycle−by−cycle current limit is set at 1200 mA (nom).
Thermal Shutdown
Internal Thermal Shutdown circuitry is provided to
protect the integrated circuit in the event that the maximum
junction temperature is exceeded. If the junction
temperature exceeds 160_C, the device shuts down. In this
mode switch Q1 and Q2 and the control circuits are all
turned off. The device restarts in soft−start after the
temperature drops below 135_C. This feature is provided
to prevent catastrophic failures from accidental device
overheating and it is not intended as a substitute for proper
heatsinking.
Short Circuit Protection
When the output is shorted to ground, the device limits
the inductor current. The duty−cycle is minimum and the
consumption on the input line is 300 mA (Typ). When the
short circuit condition is removed, the device returns to the
normal mode of operation.
Soft−Start
The NCP1522 uses soft−start (300 ms Typ) to limit the
inrush current when the device is initially enabled.
Soft−start is implemented by gradually increasing the
reference voltage until it reaches the full reference voltage.
During startup, a pulsed current source charges the internal
soft−start capacitor to provide gradually increasing
reference voltage. When the voltage across the capacitor
ramps up to the nominal reference voltage, the pulsed
current source will be switched off and the reference
voltage will switch to the regular reference voltage.
Low Dropout Operation
The NCP1522 offers a low input to output voltage
difference. The NCP1522 can operate at 100% duty cycle.
In this mode the PMOS (Q1) switches completely on.
The minimum input voltage to maintain regulation can
be calculated as:
VIN(min) + VOUT(max)
) (IOUT (RDS(on) ) RINDUCTOR))
(eq. 1)
•
•
•
•
Shutdown Mode
When the EN pin has a voltage applied of less than 0.4 V,
the NCP1522 will be disabled. In shutdown mode, the
internal reference, oscillator and most of the control
circuitries are turned off. Therefore, the typical current
VOUT: Output Voltage (Volts)
IOUT: Max Output Current
RDS(on): P−Channel Switch RDS(on)
RINDUCTOR: Inductor Resistance (DCR)
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NCP1522
APPLICATION INFORMATION
Output Voltage Selection
The corner frequency is given by:
The output voltage is programmed through an external
resistor divider connected from VOUT to FB then to GND.
For low power consumption and noise immunity, the
resistor from FB to GND (R2) should be in the
[100 k−600 k] range. If R2 is 200 k given the VFB is 0.6 V,
the current through the divider will be 3.0 mA.
The formula below gives the value of VOUT, given the
desired R1 and the R1 value:
(1 ) R1)
R2
VOUT + VFB
•
•
•
•
fc +
1
COUT
+
1
2p Ǹ2.2 mH
4.7 mF
+ 49.5 kHz
(eq. 3)
The device is intended to operate with inductance
between 1.0 mH and maximum of 4.7 mH.
If the corner frequency is moved, it is recommended to
check the loop stability depending on the output ripple
voltage accepted and output current required. For lower
frequency, the stability will be increased; a larger output
capacitor value could be chosen without critical effect on
the system. On the other hand, a smaller capacitor value
increases the corner frequency and it should be critical for
the system stability. Take care to check the loop stability.
The phase margin is usually higher than 45°.
(eq. 2)
VOUT: Output Voltage (Volts)
VFB: Feedback Voltage = 0.6 V
R1: Feedback Resistor from VOUT to FB
R2: Feedback Resistor from FB to GND
Table 2. L−C Filter Example
Input Capacitor Selection
In PWM operating mode, the input current is pulsating
with large switching noise. Using an input bypass capacitor
can reduce the peak current transients drawn from the
input supply source, thereby reducing switching noise
significantly. The capacitance needed for the input bypass
capacitor depends on the source impedance of the input
supply.
The maximum RMS current occurs at 50% duty cycle
with maximum output current, which is IO, max/2.
For NCP1522, a low profile, low ESR ceramic capacitor
of 4.7 mF should be used for most of the cases. For effective
bypass results, the input capacitor should be placed as close
as possible to the VIN pin.
Inductance (L)
TDK
C2012X5ROJ475KB
mH
10
mF
2.2
mH
4.7
mF
4.7
mH
2.2
mF
ǒ
V
V
DIL + OUT 1− OUT
L fSW
VIN
Ǔ
(eq. 4)
DIL peak to peak inductor ripple current
L inductor value
fSW switching frequency
GRM21BR71C475KA
JMK212BY475MG
1.0
The inductor parameters directly related to device
performances are saturation current and DC resistance and
inductance value. The inductor ripple current (ÄIL)
decreases with higher inductance:
GRM188R60J475KE
Taiyo Yuden
Output Capacitor (Cout)
Inductor Selection
Table 1. List of Input Capacitor
Murata
2p ǸL
The saturation current of the inductor should be rated
higher than the maximum load current plus half the ripple
current:
C1632X5ROJ475KT
DI
IL(MAX) + IO(MAX) ) L
2
Output L−C Filter Design Considerations
The NCP1522 is built in 3.0 MHz frequency and uses
voltage mode architecture. The correct selection of the
output filter ensures good stability and fast transient
response.
Due to the nature of the buck converter, the output L−C
filter must be selected to work with internal compensation.
For NCP1522, the internal compensation is internally fixed
and it is optimized for an output filter of L = 2.2 mH and
COUT = 4.7 mF.
(eq. 5)
IL(MAX) Maximum Inductor Current
IO(MAX) Maximum Output Current
The inductor’s resistance will factor into the overall
efficiency of the converter. For best performances, the DC
resistance should be less than 0.3 W for good efficiency.
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NCP1522
Table 3. List of Inductor
Table 4. List of Output Capacitor
GRM188R60J475KE
4.7 mF
VLF3010AT Series
GRM21BR60J106ME19L
10 mF
Taiyo Yuden
LQ CBL2012
GRM188R60OJ106ME
10 mF
Coil craft
DO1605−T Series
JMK212BY475MG
4.7 mF
JMK212BJ106MG
10 mF
C2012X5ROJ475KB
4.7 mF
C1632X5ROJ475KT
4.7 mF
C2012X5ROJ106K
10 mF
FDK
MIPW3226 Series
TDK
Murata
Taiyo Yuden
LPO3010
TDK
Output Capacitor Selection
Selecting the proper output capacitor is based on the
desired output ripple voltage. Ceramic capacitors with low
ESR values will have the lowest output ripple voltage and
are strongly recommended. The output capacitor requires
either an X7R or X5R dielectric.
The output ripple voltage in PWM mode is given by:
DVOUT + DIL
ǒ4
1
fSW−3
COUT
Feed−Forward Capacitor Selection
The feed−forward capacitor sets the feedback loop
response and is critical to obtain good loop stability.
Given that the compensation is internally fixed, an 18 pF
or higher ceramic capacitor is needed. Choose a small
ceramic capacitor X7R or X5R or COG dielectric.
Ǔ
) ESR (eq. 6)
In PFM mode (at light load), the output voltage is
regulated by pulse frequency modulation. The output
voltage ripple is independent of the output capacitor value.
It is set by the threshold of PFM comparator.
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NCP1522
APPLICATION BOARD
PCB Layout Recommendations
2. Place the power components (i.e., input capacitor,
inductor and output capacitor) as close together
as possible for best performance. All connecting
traces must be short, direct, and wide to reduce
voltage errors caused by resistive losses through
the traces.
3. Separate the feedback path of the output voltage
from the power path. Keep this path close to the
NCP1522 circuit. And also route it away from
noisy components. This will prevent noise from
coupling into the voltage feedback trace.
4. Place the DC−DC converter away from noise
sensitive circuitry, such as RF circuits.
The following shows the NCP1522 demo board
schematic, layout, and bill of materials:
Good PCB layout plays an important role in switching
mode power conversion. Careful PCB layout can help to
minimize ground bounce, EMI noise and unwanted
feedback that can affect the performance of the converter.
Hints suggested below can be used as a guideline in most
situations.
1. Use star−ground connection to connect the IC
ground nodes and capacitor GND nodes together
at one point. Keep them as close as possible, and
then connect this to the ground plane through
several vias. This will reduce noise in the ground
plane by preventing the switching currents from
flowing through the ground plane.
L
VIN
1
VIN
2
GND
LX
VOUT
5
CIN
COUT
R1
OFF ON
3
EN
FB
4
R2
Figure 25. NCP1522 Board Schematic
Figure 26. NCP1522 Board Layout
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13
Cff
NCP1522
U1
J1
1
2
VFVIN
VIN
C1
4.7 mF
Power
1
0
LX
LX
1
EN
FB
L1
OUTPUT
1
2
VOUT
2
2.2 mH
2 GND
EN 3
0
VP
5
C2
4.7 mF
R1
220 R
C3
18 pF
J3
0
4
R2
220 R
NCP152x
VP
J5
1
2
3
EN
J4
R3
220 K
BNCH
0
0
Figure 27. Schematics
Figure 28. Silkscreen Layer
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14
0
CON3
0
NCP1522
Figure 29. Board Layout (Top View)
Figure 30. Board Layout (Bottom View)
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15
NCP1522
Bill of Materials
Item
Part Description
Ref
PCB Footprint
Manufacturer
Manufacturer
Reference
U1
TSOP−5
On Semiconductor
NCP1522
1
NCP1522 DC−DC Converter
2
4.7 mF Ceramic Capacitor
6.3 V X5R
C1, C2
0805
Murata
GRM21 Series
3
18 pF Ceramic Capacitor
50 V COG
C3
0603
Murata
GRM188 Series
4
SMD Resistor 220 K
R1, R2, R3
0805
Vishay−Draloric
CRCW0805
5
SMD Inductor
L1
1605
Coilcraft
DO1605 Series
6
I/O Connector can be plugged by
BLZ5.08/2 (Weidmüller reference)
J1, J3
−
Weidmüller
SL5.08/2/90B
7
Jumper Header vertical mount 3*1,
2.54 mm
J5
−
Tyco Electronics/AMP
5−826629−0
8
Jumper Connector, 400 mils
J6, J7
−
Harwin
D3082−B01
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16
NCP1522
PACKAGE DIMENSIONS
TSOP−5
SN SUFFIX
CASE 483−02
ISSUE F
NOTE 5
2X
0.10 T
2X
0.20 T
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ASME Y14.5M, 1994.
2. CONTROLLING DIMENSION: MILLIMETERS.
3. MAXIMUM LEAD THICKNESS INCLUDES
LEAD FINISH THICKNESS. MINIMUM LEAD
THICKNESS IS THE MINIMUM THICKNESS
OF BASE MATERIAL.
4. DIMENSIONS A AND B DO NOT INCLUDE
MOLD FLASH, PROTRUSIONS, OR GATE
BURRS.
5. OPTIONAL CONSTRUCTION: AN
ADDITIONAL TRIMMED LEAD IS ALLOWED
IN THIS LOCATION. TRIMMED LEAD NOT TO
EXTEND MORE THAN 0.2 FROM BODY.
D 5X
0.20 C A B
5
1
4
2
3
M
B
S
K
L
DETAIL Z
G
A
DIM
A
B
C
D
G
H
J
K
L
M
S
DETAIL Z
J
C
0.05
SEATING
PLANE
H
T
MILLIMETERS
MIN
MAX
3.00 BSC
1.50 BSC
0.90
1.10
0.25
0.50
0.95 BSC
0.01
0.10
0.10
0.26
0.20
0.60
1.25
1.55
0_
10 _
2.50
3.00
SOLDERING FOOTPRINT*
0.95
0.037
1.9
0.074
2.4
0.094
1.0
0.039
0.7
0.028
SCALE 10:1
mm Ǔ
ǒinches
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
ON Semiconductor and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any
liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental
damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over
time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under
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or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death
may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees,
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NCP1522/D