NCP5010FCT1G [ONSEMI]
500 mW Boost Converter for White LEDs; 500 mW的升压转换器，用于白光LED
| 型号： | NCP5010FCT1G |
| 厂家： | 
ONSEMI |
| 描述： | 500 mW Boost Converter for White LEDs |
| 文件： | 总18页 (文件大小：174K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
NCP5010
500 mW Boost Converter for
White LEDs
The NCP5010 is a fixed frequency PWM boost converter with
integrated rectification optimized for constant current applications
such as driving white LEDs. This device features small size, minimal
external components and high−efficiency for use in portable
applications and is capable of providing up to 500 mW output power
to 2−5 series connected white LEDs. A single resistor sets the LED
current and the CTRL pin can be pulse width modulated (PWM) to
reduce the LED Current.
The device includes True−Cutoff circuitry to disconnect the load
from the battery when the device is put into standby mode. To protect
the device, an output overvoltage protection, and short circuit
protection have been incorporated. The NCP5010 is housed in a low
profile, space efficient 1.7 x 1.7 mm Flip−Chip package. The device
has been optimized for use with small inductors and ceramic
capacitors.
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MARKING
DIAGRAM
A1
8−Pin Flip−Chip
FC SUFFIX
DAXG
AYWW
CASE 499AJ
1
DAX = Specific Device Code
G
= Pb−Free Package
= Assembly Location
= Year
A
Y
WW = Work Week
Features
• 2.7 to 5.5 V Input Voltage Range
• Efficiency: 84% for 5 LED (V = 3.5 V by LED) at 30 mA and
PIN CONNECTIONS
F
4.2 V V
IN
• Low Noise 1 MHz PWM DC−DC Converter
• Open LED Protection and Short Circuit Protection
• Serial LEDs Architecture for Uniform Current Matching
• 1 mA Shutdown Current Facility with True−Cutoff
• Very Small 8−Pin Flip−Chip 1.7 x 1.7 mm Package
• This is a Pb−Free Device
A1
A2
A3
AGND CTRL
B1
NC
B3
FB
V
IN
C1
C2
C3
V
OUT
SW PGND
Top View
Typical Applications
• White LED Backlighting for Small Color LCD Displays
• Cellular Phones
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 16 of this data sheet.
• Digital Cameras
• MP3 Players
• High Efficiency Step−up Converter
90
80
70
60
50
40
30
20
10
0
V
OUT
= 5 LED (18 V)
V
OUT
= 3 LED (11 V)
V
IN
= 4.2 V
1
10
(mA)
100
I
OUT
Figure 1. Efficiency vs. Output Current
©
Semiconductor Components Industries, LLC, 2006
1
Publication Order Number:
August, 2006 − Rev. 1
NCP5010/D
NCP5010
V
bat
2.7 to 5.5 V
L1
22 mH
LED
C
in
4.7 mF 0603
X5R 6.3V
A2
A3
C1
V
OUT
ENABLE
CTRL
NC
C
out
1 mF 0805
LED
X5R 25V
NCP5010
R
fb
24
Figure 2. Typical Application Circuit
PIN FUNCTION DESCRIPTION
PIN
PIN NAME
TYPE
DESCRIPTION
A1
AGND
POWER
System ground for the analog circuitry. A high quality ground must be provided to avoid spikes and/
or uncontrolled operations. This pin is to be connected to the PGND pin.
B1
C1
V
POWER
POWER
Power Supply Input. A ceramic capacitor with a minimum value of 1 mF/6.3 V (X5R or X7R) must be
connected to this pin. This capacitor should be placed as close as possible to this pin. In addition,
one end of the external inductor is to be connected at this point.
IN
V
OUT
DC−DC converter output. This pin should be directly connected to the load and a low ESR
(<30 mW) 1 mF (min) 25 V bypass capacitor. This capacitor is required to smooth the current flowing
into the load, thus limiting the noise created by the fast transients present in this circuit. Since this is
a current regulated output, this pin has over voltage protection to protect from open load conditions.
Care must be taken to avoid EMI through the PCB copper tracks connected to this pin.
A2
C2
CTRL
SW
INPUT
An Active High logic level on this pin enables the device. A built−in pulldown resistor disables the
device if the pin is left open. This pin can also be used to control the average current into the load
by applying a low frequency PWM signal. If a PWM signal is applied, the frequency should be high
enough to avoid optical flicker but be no greater than 1 kHz.
POWER
Power switch connection for inductor. Typical application will use a coil from 10 mH to 22 mH and
must be able to handle at least 350 mA. If the desired output power is above 300 mW, the inductor
should have a DCR < 1.4 W.
A3
B3
NC
FB
N/A
Not Connected
INPUT
Feedback voltage input used to close the loop by means of a sense resistor connected between the
primary LED branch and the ground. The output current tolerance is depends upon the accuracy of
this resistor and a 5% or better accuracy metal film resistor is recommended. An analog dimming
signal can be applied to this point to reduce the output current. Please refer to the application
section for additional details.
C3
PGND
POWER
Power ground. A high quality ground must be used to avoid spikes and/or uncontrolled operation.
Care must be taken to avoid high−density current flow in a limited PCB copper track. This pin is to
be connected to the AGND pin.
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NCP5010
MAXIMUM RATINGS
Rating
Symbol
Value
7.0
Unit
V
Power Supply Voltage (Note 2)
Over Voltage Protection
V
IN
V
OUT
24
V
Human Body Model (HBM) ESD Rating (Note 3)
Machine Model (MM) ESD Rating (Note 3)
ESD HBM
ESD MM
CTRL
2000
200
V
V
Digital Input Voltage
Digital Input Current
−0.3 < V < V +0.3
V
IN
bat
1.0
mA
Power Dissipation @ T = +85 °C
P
D
150
mW
A
Thermal Resistance Junction−to−Air
8−Pin Flip−Chip Package
R
q
JA
°C/W
(Note 6)
Operating Ambient Temperature Range
Operating Junction Temperature Range
Storage Temperature Range
T
−40 to +85
−40 to +125
−65 to +150
°C
°C
°C
A
T
J
T
stg
Maximumratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit values
(not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied, damage
may occur and reliability may be affected.
1. Maximum electrical ratings are defined as those values beyond which damage to the device may occur at T = 25°C.
A
2. According to JEDEC standard JESD22−A108B.
3. This device series contains ESD protection and passes the following tests:
Human Body Model (HBM) 2.0 kV per JEDEC standard: JESD22−A114 for all pins.
Machine Model (MM) 200 V per JEDEC standard: JESD22−A115 for all pins.
4. Latchup Current Maximum Rating: 100 mA per JEDEC standard: JESD78.
5. Moisture Sensitivity Level (MSL): 1 per IPC/JEDEC standard: J−STD−020A.
6. For the 8−Pin Flip−Chip CSP Package, the R
is highly dependent on the PCB Heatsink area. For example R
can be to 195°C/W with
q
JA
q
JA
50 mm total area and also 135°C/W with 500 mm. All the bumps have the same thermal resistance and need to be connected thereby optimizing
the power dissipation.
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NCP5010
ELECTRICAL CHARACTERISTICS (Limits apply for T between −40°C to +85°C and V = 3.6 V, unless otherwise noted)
A
IN
Pin
B1
Symbol
Rating
Min
Typ
Max
5.5
Unit
V
V
IN
Supply Voltage
2.7
C2
I
Switch Current Limit
280
420
0.6
1.0
95
560
1.0
mA
W
PEAK_MAX
NMOS R
Internal Switch On Resistor
PWM Oscillator Frequency
Maximum Duty Cycle
DS(on)
F
0.8
91
1.2
MHz
%
OSC
M
DUTY
E
FF
Efficiency (Note 7)
84
%
C1
C1
C1
OVP
OVP
Overvoltage Clamp Voltage
Overvoltage Clamp Hysteresis
Output power (Note 8)
20
22
V
ON
1.0
V
H
P
OUT
mW
V
IN
V
IN
= 3.1 V
< 3.1 V
500
300
C1
B3
I
Minimum Output Current Controlled No Skip Mode
(Note 9)
1.0
mA
mV
OUT
F
Feedback Voltage Threshold in Steady State
Overtemperature range
At 25°C
BV
475
490
500
500
525
510
C1
B1
F
Feedback Voltage Line Regulation (Notes 9 and 10)
From DC to 100 Hz
%/V
V
BVLR
0.2
0.5
U
V
IN
Undervoltage Lockout measured at 25°C
Threshold to Enable the Converter
Threshold to Disable the Converter
VLO
2.2
2.0
2.4
2.2
2.6
2.4
B1
C1
B1
U
Undervoltage Lockout Hysteresis
Short Circuit Output Current
200
20
mV
mA
VLOH
I
OUTSC
S
CPT
Short Circuit Protection Threshold
% of V
IN
Detected
Released
35
47
50
67
65
87
B1
C2
ISTDB
Stand by Current, I
= 0 mA, CTRL = Low
2.0
mA
OUT
V
bat
= 4.2 V
I
Q
Quiescent Current
Device Not Switching (BF = VIN)
mA
0.4
1.0
Device Switching (R disconnected)
FB
A2
A2
A2
V
V
Voltage Input Logic Low
0.3
V
V
IL
Voltage Input Logic High
CTRL Pin Pulldown Resistance
1.2
IH
R
175
370
kW
CTRL
7. Efficiency is defined by 100 * (P / P ) at 25°C
out
in
V
= 4.2 V with L= Coilcraft DT1608C−223
IN
I
= 30 mA, Load = 5 LEDs (V = 3.5 V per LED) bypassed by 1 mF X5R
OUT
F
8. Guaranteed by design and characterized with L = 22 mH, DCR = 0.7 W max.
9. Load = 4 LEDs (V = 3.5 V by LED), C = 1 mF X5R, L= Coilcraft DT1608C−223.
F
OUT
= 15 mA.
10.V = 3.6 V, Ripple = 0.2 V P−P, I
IN
OUT
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NCP5010
TYPICAL OPERATING CHARACTERISTICS
Condition: Efficiency = 100 x (Number of LED stacked x VLED x ILED)/PIN
90
80
70
60
50
90
80
V
IN
= 3.3 V
V
= 2.7 V
IN
V
= 4.2 V
70
60
50
V
IN
= 3.3 V
IN
V
= 2.7 V
IN
V
= 4.2 V
IN
0
10
20
30
40
(mA)
50
60
70
0
10
20
30
I
40
(mA)
50
60
70
I
OUT
OUT
Figure 3. Efficiency vs. Current @ 3 LEDS (10.5 V)
L = Coilcraft DT1608C−223
Figure 4. Efficiency vs. Current @ 3 LEDS (10.5 V)
L = TDK VLF4012AT−220
90
80
70
60
50
90
80
V
= 3.3 V
IN
V
IN
= 2.7 V
V
= 3.3 V
V
= 4.2 V
IN
IN
V
IN
= 2.7 V
70
60
V
= 4.2 V
IN
50
0
10
20
30
I
40
(mA)
50
60
70
0
10
20
30
I
40
50
60
70
(mA)
OUT
OUT
Figure 5. Efficiency vs. Current @ 4 LEDS (14 V)
L = Coilcraft DT1608C−223
Figure 6. Efficiency vs. Current @ 4 LEDS (14 V)
L = TDK VLF4012AT−220
90
80
70
60
50
90
80
70
60
50
V
IN
= 3.3 V
V
= 2.7 V
IN
V
= 4.2 V
V
IN
= 3.3 V
IN
V
IN
= 2.7 V
V
= 4.2 V
IN
0
10
20
30
40
(mA)
50
60
70
0
10
20
30
40
(mA)
50
60
70
I
OUT
I
OUT
Figure 7. Efficiency vs. Current @ 5 LEDS (17.5 V)
L = Coilcraft DT1608C−223
Figure 8. Efficiency vs. Current @ 5 LEDS (17.5 V)
L = TDK VLF4012AT−220
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NCP5010
TYPICAL OPERATING CHARACTERISTICS
Condition: Efficiency = 100 x (Number of LED stacked x VLED x ILED)/PIN
90
80
70
60
50
40
30
20
90
I
= 33 mA
OUT
I
= 33 mA
OUT
80
70
60
50
40
30
20
I
= 10 mA
= 1 mA
OUT
I
= 10 mA
= 1 mA
OUT
I
= 23 mA
OUT
I
= 23 mA
OUT
I
OUT
I
OUT
2.5
3.0
3.5
4.0
4.5
5.0
5.5
2.5
3.0
3.5
4.0
4.5
5.0
5.5
100
100
V
(V)
V
(V)
IN
IN
Figure 9. Efficiency vs. VIN @ 3 LEDS (10.5 V)
L = Coilcraft DT1608C−223
Figure 10. Efficiency vs. VIN @ 4 LEDS (14 V)
L = Coilcraft DT1608C−223
90
80
70
60
50
40
30
20
510
505
500
I
= 28 mA
OUT
I
= 10 mA
= 1 mA
OUT
V
IN
= 3.6 V
I
= 23 mA
OUT
V
= 5.5 V
IN
I
OUT
V
IN
= 2.7 V
495
490
2.5
3.0
3.5
4.0
4.5
5.0
5.5
−40
−20
0
20
40
60
80
TEMPERATURE (°C)
V
(V)
IN
Figure 11. Efficiency vs. VIN @ 5 LEDS (17.5 V)
L = Coilcraft DT1608C−223
Figure 12. Feedback Voltage vs. Temperature
1.04
1.02
1.00
0.98
0.96
900
800
700
600
500
400
300
V
IN
= 3.6 V
V
= 3.6 V
IN
V
= 5.5 V
IN
V
= 2.7 V
IN
V
= 5.5 V
80
IN
V
IN
= 2.7 V
0
−40
−20
0
20
40
60
−40
−20
20
40
60
80
100
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 13. Oscillator Frequency vs. Temperature
Figure 14. NMOS RDS(on) vs. Temperature
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NCP5010
TYPICAL OPERATING CHARACTERISTICS
3
2
1
0
3 LEDs
4 LEDs
5 LEDs
2.5
3.0
3.5
4.0
(V)
4.5
5.0
5.5
V
IN
Figure 16. Typical VOUT Ripple in OVP Conditions
1 VOUT, 500 mV/div, AC 3 VOUT, 5 V/div, DC
Figure 15. Typical Skip Mode Threshold vs. VIN
(COUT = 1 mF X5R 25 V)
Figure 17. Continuous Current Mode (CCM)
Figure 18. Discontinuous Current Mode (DCM)
1 SW, 5 V/div DC, 4 ILED, 50 mA/div, DC, IOUT = 15 mA
1 SW, 5 V/div DC, 4 ILED, 50 mA/div, DC, IOUT = 1 mA
Figure 19. Startup for LED Operating, 4 LEDS
RBF = 22 W, 1 CTRL, 2 V/div DC, 2 FB, 500 mV/div DC,
4 IL 100 mA/div, T = 100 ms/div
Figure 20. Duty Cycle Control Waveforms
1 CTRL, 2 V/div DC, 2 FB, 500 mV/div DC,
4 IL 100 mA/div, T = 1 ms/div
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NCP5010
TYPICAL OPERATING CHARACTERISTICS
Figure 21. Typical Ripple for Voltage Operation
1 SW, 10 V/div DC, 2 FB, 500 mV/div DC, 3 VOUT
20 mV/div AC, T = 500 ns/div
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NCP5010
DETAIL OPERATING DESCRIPTION
V
Bat
L
2.7 to 5.5 V
C
in
22 mH
SW
V
1 mF, 6.3 V X5R 0603
IN
B1
C2
A1
AGND
OVP
COMP
OVP
UVLO
COMP
−
+
+
UVLO
UVLO REF
−
MAX DUTY
OVP REF
CYCLE COMP
V
C1
THERMAL
OUT
−
M DUTY REF
MAX D
PROTECTION
FB
C
1 mF
25 V
out
+
−
B3
ERROR
AMP
+
−
RST
PWM
COMP
+
DRIVER
FB REF
X5R 0805
RAMP
COMP
SHORT
CIRCUIT
PROTECTION
SET
ONE
SHOT
SENSE
CURRENT
V
IN
R
FB
+
IPEAK MAX
IPEAK
COMP
−
OSC
1 Mhz
250 k
IPEAK MAX
CTRL A2
C3
PGND
Figure 22. Functional Block Diagram
Operation
The internal oscillator provides a 1 MHz clock signal to
trigger the PWM controller on each rising edge (SET signal)
which starts a cycle. During this phase the low side NMOS
switch is turned on thus increasing the current through the
inductor. The switch current is measured by the SENSE
CURRENT and added to the RAMP COMP signal. Then
PWM COMP compares the output of the adder and the signal
from ERROR AMP. When the comparator threshold is
exceeded, the NMOS switch is turned off until the rising edge
of the next clock cycle. In addition, there are six functions
which can reset the flip−flop logic to switch off the NMOS.
The MAX DUTY CYCLE COMP monitors the pulse width
and if it exceeds 95% (nom) of the cycle time the switch will
be turned off. This limits the switch from being on for more
than one cycle. Due to IPEAK COMP, the current through the
The NCP5010 DC−DC converter is based on a Current
Mode PWM architecture which regulates the feedback
voltage at 500 mV under normal operating conditions. The
boost converter operates in two separate phases (See
Figure 23). The first one is T
charged by current from the battery to store up energy,
followed by T step where the power is transmitted
when the inductor is
ON
OFF
through the internal rectifier to the load. The capacitor
C
is used to store energy during the T
time and to
stage thus
OUT
OFF
supply current to the load during the T
constantly powering the load.
ON
Start
Cycle
SW
inductor is monitored and compared with the I
PEAK_MAX
I
peak
1 MHz
threshold set at 440 mA (nom). If the current exceeds this
value, the controller is will turn off the NMOS switch for the
remainder of the cycle. This is a safety function to prevent any
excessive current that could overload the inductor and the
power stage. The four other safety circuits are SHORT
CIRCUIT PROTECTION, OVP, UVLO, and THERMAL
PROTECTION. Please refer to the detail in following
sections.
IL
I
valley
T
on
T
off
I
SW
The loop stability is compensated by the ERROR AMP
built in integrator. The gain and the loop bandwidth are
fixed internally and provides a phase margin greater than
45° whatever the current supplied.
I
out
Figure 23. Basic DC−DC Operation
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NCP5010
300
250
200
150
100
50
LED Current Selection
The feedback resistor (R ) determines the average
maximum current through the LED string. The control loop
regulated the current such that the average voltage at the FB
input is 500 mV (nom). For example, should one need a
FB
L = 10 mH
20 mA output current in the primary branch, R should be
selected according to the following equation:
FB
F
500 mV
20 mA
BV
R
FB
+
+
+ 25 W
I
OUT
L = 15 mH
L = 22 mH
30
In white LED applications it is desirable to operate the
LEDs at a specific operating current as the color will shift
as the bias current is changed. As a result of this effect, it
is recommended to dim the LED string by a pulse width
modulation techniques. A low frequency PWM signal can
be applied to the CTRL input and by varying the duty cycle
the brightness of the LED can be changed. To avoid any
optical flicker, the frequency must be higher than 100 Hz
and preferably less than 1 kHz. Due to the soft−start
function set at 600 ms (nom) with higher frequency the
device remains active but the brightness can decrease.
Nevertheless in this case, a dimming control using a
filtered PWM signal (See Figure 33) can be used. Also for
DC voltage control the same technique is suitable and the
filter is takes away.
VIN = 3.1 V
VIN = 4.2 V
10
20
40
50
60
70
80
I
(mA)
OUT
Figure 24. Peak Inductor Currents vs. IOUT (mA)
@ 3 LEDs, 10.5 V
300
L = 10 mH
250
200
150
Inductor Selection
L = 15 mH
To choose the inductor there are three different electrical
parameters that need to be considered, the absolute value
of the inductor, the saturation current and the DCR. In
normal operation, this device is intended to operate in
Continuous Conduction Mode (CCM) so the following
equation below can be used to calculate the peak current:
100
VIN = 3.1 V
VIN = 4.2 V
L = 22 mH
50
10
20
30
40
50
(mA)
60
70
80
I
OUT
I
V
2LF
D
OUT
IN
Figure 25. Peak Inductor Currents vs. IOUT (mA)
@ 4 LEDs, 14 V
I
+
)
PEAK
(
)
h 1 * D
In the equation above, V is the battery voltage, I
the load current, L the inductor value, F the switching
frequency, and the duty cycle D is given by:
is
IN
OUT
300
250
V
IN
D + ǒ1 *
Ǔ
V
OUT
200
L = 10 mH
h is the global converter efficiency which can vary with
load current (see Figure 3 thru Figure 8). A good
approximation is to use h = 0.8. Figure 24 − Figure 26 are
a graphical representation of the above equations, as a
150
L = 15 mH
function of the desired I
, V , and number of LEDs in
L = 22 mH
OUT IN
100
VIN = 3.1 V
series (V = 3.5 V nominal). The curves are limited to an
F
VIN = 4.2 V
I
of 300 mA. It is important to analyze this at
PEAK_MAX
50
10
worst case Vf conditions to ensure that the inductor current
rated is high enough such that it not saturate.
20
30
40
50
60
70 80
I
(mA)
OUT
The recommended inductor value should range between
10 mH and 22 mH. As can be seen from the curves, as the
inductor size is reduced, the peak current for a given set of
conditions increases along with higher current ripple so it
is not possible to deliver maximum output power at lower
inductor values.
Figure 26. Peak Inductor Currents vs. IOUT (mA)
@ 5 LEDs, 17.5 V
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NCP5010
Finally an acceptable DCR must be selected regarding
losses in the coil and must be lower than 1.4 W to limit
excessive voltage drop. In addition, as DCR is reduced,
overall efficiency will improve. Some recommended
inductors include but are not limited to:
reaches 66% of V , then the PWM circuitry is enabled. In
normal conditions when the device is enabled by an active
high signal on CTRL, the short circuit condition continues
until the output capacitor is charged by the limited current
IN
up to 66% of V .
IN
TDK VLF4012AT−220MR51
TDK VLP4612T−220MR34
TDK VLP5610T−220MR45
Coilcraft LPO6610−223M
Coilcraft DO1605T−223MX
Coilcraft DT1608C−223
V
OUT
2/3 V
1/2 V
IN
IN
T
Normal
Running Occurs Current limited at 20mA Detected Converter
Converter in Standby
SC
Short−Circuit Condition End of Short−Circuit
Capacitor Selection
Starts Again
To minimize the output ripple, a low ESR multi−layer
ceramic capacitor type X5R or equivalent should be
selected. For LED driver applications a 1 mF (min) 25 V is
adequate. The NCP5010 can be operated in a voltage mode
configuration (see Figure 34) for applications such as
OLED power. Under these conditions, C
increased to 2.2 mF, 25 V or more to reduce the output
ripple.
Figure 27. Example of the VOUT Voltage Behavior
When Short−Circuit Arises
Overvoltage Protection (OVP)
If there is an open load condition such as a loose
connection to the White LED string, the converter will
can be
OUT
provide current to the C capacitor and the voltage at the
out
The input needs to be bypassed by a X5R or an equivalent
output will rise rapidly. This could cause damage to the part
if there was not some external clamping Zener clamping
circuit. To eliminate the need for these external
components, the NCP5010 incorporates an OVP circuit
which monitors the output voltage with a resistive divider
network and a comparator and voltage reference. If the
output reaches 22 V (nominal), the OVP circuit will detect
a fault and inhibit PWM operation. This comparator has
1 V of hysteresis so when the load is reconnected and the
voltage drops below 21 V, the PWM operation will resume
automatically. The 22 V OVP threshold allows the use of
25 V ceramic capacitors for the output filter capacitor.
low ESR ceramic capacitor near the V pin. A 1 mF, 6.3 V
is enough for most applications. However, if the connection
IN
between V and the battery is too long then a 4.7 mF or
IN
higher ceramic capacitor may be needed. Some
recommended capacitors include but are not limited to:
TDK C1608X5R1E105MT
TDK C2012X5R1E105MT
TDK C1608X5R0J105MT
TDK C2012X5R1E225MT
Murata GRM185R61A105KE36D
Murata GRM188R60J475KE19D
Murata GRM216R61E105KA12D
Undervoltage Lock Out (UVLO)
To ensure proper operation under all conditions, the
device has a built−in undervoltage lock out (UVLO)
circuit. During power−up, the device will remain disabled
until the input voltage exceeds 2.4 V nominal. This circuit
has 200 mV of hysteresis to provide noise immunity to
transient conditions.
Short−Circuit Protection
If V
is falls below 50% of V then a short−circuit
IN
OUT
condition is detected. When this event is detected, the
PWM circuitry is disabled and the NMOS power switch is
not turned on. Power will be supplied to the load through
the inductor, rectifier and high side switch. Once V
OUT
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11
NCP5010
Layout Recommendations
As with all switching DC/DC converter, care must be
observed to the PCB board layout and component
placement. To prevent electromagnetic interference (EMI)
problems and reduce voltage ripple of the device any
copper trace which see high frequency switching path
should be optimized. So the input and output bypass
ceramic capacitor, C and C
as depicted Figure 2 must
IN
OUT
be placed as close as possible the NCP5010 and connected
directly between pins and ground plane. In additional, the
track connection between the inductor and the switching
input, SW pin must be minimized to reduce EMI radiation.
Finally it is always good practice to keep way sensitive
tracks such as feedback connection from switched signal
like SW or VOUT connections. Figure 28 shown an
example of optimized PCB layout.
Figure 28. Recommended PCB Layout
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12
NCP5010
TYPICAL APPLICATION CIRCUITS
Basic Feedback
Figure 29 is a basic application where a regulated courant
is drive in a string of LEDs. A 20.8 mA current is fixed by
R1 and LEDs are dim with PWM apply on CTRL pin.
V
Bat
2.7 to 5.5 V
C2
1 mF 0805
X5R 25 V
LED
L1
22 mH
C
in
4.7 mF 0603
X5R 6.3 V
A2
C1
CTRL
PWM
V
OUT
LED
L1: TDK VLF4012AT−220MR51
C1: TDK C1608X5R0J475MT
C2: TDK C2012X5R1E105MT
NCP5010
R1
24
Figure 29. Typical Semi−Pulsed Mode of Operation
Different Supply
need a power delivered for example from an LDO. Care
The NCP5010 can operate from two different supply:
must be observed to have always V
above V and
BAT
IN
One end of the inductor (V ) can be directly connected
minimum output voltage range will be V
voltage.
BAT
BAT
to a battery like 4 cell alkaline or 2 cell Li−Ion. And V pin
IN
V
Bat
V
in
C2
LED
2.7 to 5.5 V
L1
1 mF 0805
22 mH
X5R 25 V
C
in
4.7 mF 0603
X5R 6.3 V
A2
C1
CTRL
ENABLE
V
OUT
LED
L1: TDK VLF4012AT−220MR51
NCP5010
C1: TDK C1608X5R0J475MT
C2: TDK C2012X5R1E105MT
R1
24
Figure 30. Operate from Different Supply
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13
NCP5010
Multiple LEDs String
Since the output voltage in limited at 22 V (nom.), one
can arrange the LEDs in 2 or more string. Figure 31 shows
two LEDs branches where the constant current is regulated
in primary branch and the secondary branch is selected by
Q1. The number of LED in each string have to be the same.
V
Bat
2.7 to 5.5 V
X5R 6.3 V
C2
1 mF 0805
LED
LED
L1
22 mH
X5R 25 V
C1
4.7 mF 0603
X5R 6.3 V
A2
C1
V
OUT
CTRL
ENABLE
LED
LED
NCP5010
L1: TDK VLF4012AT−220MR51
C1: TDK C1608X5R0J475MT
C2: TDK C2012X5R1E105MT
R1
24
R2
24
PRIMARY BRANCH
ENABLE SECONDARY BRANCH
Q1
N
Figure 31. Multiple LED String Application
Matched LEDs Branches
like this the current in the secondary branch I2 equal the
current in primary branch I1. Thank to this current mirror
the number of LEDs in secondary branch could be lower or
equal than primary one.
Should one need to control precisely the current in two
LEDs branches the schematic Figure 32 can be used. An
dual NPN BC847BD is used to form a current mirror Q1
V
Bat
2.7 to 5.5 V
X5R 6.3 V
C2
1 mF 0805
LED
LED
L1
22 mH
X5R 25 V
C1
4.7 mF 0603
X5R 6.3 V
A2
C1
V
OUT
CTRL
ENABLE
LED
LED
I2
Q1
I1
NPN Duals
NCP5010
Q1: ON SEMICONDUCTOR BC847BDW1T1
L1: TDK VLF4012AT−220MR51
C1: TDK C1608X5R0J475MT
C2: TDK C2012X5R1E105MT
R1
24
R2
24
Figure 32. Matched 2 Branches of LEDs
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14
NCP5010
Analog Dimming Control
signal is put from outside to R2 there is no voltage drop
across R3 and I = V /R4. When the voltage put to R2
is increasing the loop balance output voltage to get always
500 mV to FB pin. Thereby voltage across R4 decreases
like this the current in the string of LEDs.
When the NCP5010 is in steady state the output voltage
is controlled in order to have 500 mV to the feedback input
(FB pin). The principle of this schematic is bias by a
resistive network R2/R3 the feedback voltage. If not any
OUT
FB
V
Bat
2.7 to 5.5 V
C2
1 mF 0805
LED
L1
22 mH
X5R 25 V
C1
4.7 mF 0603
X5R 6.3 V
A2
C1
V
OUT
CTRL
ENABLE
LED
R3
18 k
NCP5010
R1 10 k
R4
24
R2
100 k
L1: TDK VLF4012AT−220MR51
C1: TDK C1608X5R0J475MT
C2: TDK C2012X5R1E105MT
C3: Standard Capacitor
PWM SIGNAL
C3
470 nF
Average Network
DC VOLTAGE
Select
Figure 33. Dimming Control Using a Filtered PWM Signal or a DC Voltage
DC/DC Boost Application
The NCP5010 can be used as DC/DC Boost converter to
deliver constant voltage to powering load like OLED or
LCD biasing. An external resistive network is connected to
sense the output voltage and close the loop.
R1 ) R2
ǒ
Ǔ
V
out
+ 0.5
R1
V
Bat
2.7 to 5.5 V
L1
22 mH
C1
4.7 mF 0603
X5R 6.3 V
15 V / 35 mA
C2
A2
C1
V
OUT
CTRL
ENABLE
2.2 mF 0805
X5R 25 V
R
290 k
NCP5010
L1: TDK VLF4012AT−220MR51
C1: TDK C1608X5R0J475MT
C2: TDK C2012X5R1E225MT
R
10 k
Figure 34. OLED or LCD Bias Supply
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15
NCP5010
ORDERING INFORMATION
†
Device
Marking
DAX
Operating Temperature Range
Package
Shipping
NCP5010FCT1G
−40°C to +85°C
8−Pin Flip−Chip CSP
(Pb−Free)
3000 Tape and Reel
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
Two type of demo boards available:
• The NCP5010EVB board which configures the device driving a string of 2−5 White LEDs in series.
• The NCP5010BIASEVB board for applications such as powering an OLED panel or LCD biasing.
Finally in addition to these demo boards, Application Note “ANDXXXX/D” deals with configuring the NCP5010 with a
high side sense resistor.
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NCP5010
PACKAGE DIMENSIONS
8−PIN FLIP−CHIP
FC SUFFIX
CASE 499AJ−01
ISSUE A
−A−
E
NOTES:
4 X
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETERS.
3. COPLANARITY APPLIES TO SPHERICAL
CROWNS OF SOLDER BALLS.
D
0.10
C
−B−
PIN 1
INDICATOR
MILLIMETERS
DIM
A
MIN
MAX
0.6 BSC
A1 0.210
A2 0.330
0.270
0.390
TOP VIEW
A
D
E
1.70 BSC
1.70 BSC
0.290 0.340
0.500 BSC
0.10
0.05
−C−
C
b
e
C
D1
E1
1.000 BSC
1.000 BSC
A2
A1
SEATING
PLANE
SOLDERING FOOTPRINT
SIDE VIEW
0.50
0.0197
D1
e
DIE SIZE MAY VARY
C
B
A
E1
e
8X
b
0.50
0.0197
0.05 C A B
0.03 C
1
2
3
BOTTOM VIEW
0.265
0.01
mm
inches
ǒ
Ǔ
SCALE 20:1
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17
NCP5010
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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
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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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NCP5010/D
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