NCL30000: 100-277 Vac 25 W High Power Factor Flyback LED Driver

DN05031/D
Design Note – DN05031/D
25 watt Offline Hi-Power Factor LED Driver
Device
NCL30000
Application
LED Driver
Input Voltage
90 – 305 V ac
Output Power
25 watts
Output Current
Ripple
Nominal Voltage
Max Voltage
Topology
Flyback
I/O Isolation
Yes
700 mA
413 mA pk-pk
36 volts
44 volts
Typical Power Factor
Typical THDi
Typical Efficiency
Inrush Limiting / Fuse
Operating Temp. Range
0.997
5.6%
88.0%
1 Amp fuse
-40 to 70 ºC
Circuit Description
Recently, new generations of high power chip-on-board
LED products have entered the markets that integrate a
large number of LED on a single substrate. These
devices have high lumen output and can be optimized for
either high efficacy or high CRI with a wide range of color
temperatures so they can be used in indoor applications
like retail downlighting as well as outdoor applications
like wall washers for example.
The focus of this design note is the development of an
offline, high power factor corrected single stage driver
which can support extended wide AC mains from 90-305
V ac. This addresses standard global AC line voltages as
well as the 277 V ac commercial input required for the
United States.
High power factor and low harmonic content are typically
required for commercial lighting. In the US, LED
luminaires that meet Energy star requirements need to
have a PF ≥ 0.9 and globally EN61000-3-2 Class C
lighting requirements define lower thresholds for
harmonic currents when the input power is > 25 W.
One example of this class of LEDs is the Sharp Mega
ZENIGATA family. For this design, the 25 watt version
was selected which consists of an array of 168 LEDs
which comprises 14 strings of 12 LEDs in series. Since
this appears as a single LED assembly, a single channel
constant current driver is required.
June 2012, Rev. 0
The Sharp GW5D series (image above) is rated at
typically 2300-2600 lumens at 25 ºC case temperature
when driven at 700 mA and the forward voltage range is
34-40 V dc under those conditions.
Shown below are the design guidelines for this driver:
•
•
•
•
•
•
•
Input range: 90 – 305 V ac
Output current: 700 mA
Output voltage: 36 volts typical
Efficiency: >87%
Power Factor: >0.95
Isolated Output
Open/Short Circuit protection
The NCL30000LED3GEVB demonstration board was
used as the development platform. This demo board was
selected as it provides wide input voltage range covering
100 to 277 volt applications with applicable tolerance.
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DN05031/D
The low profile design provides a compact solution. The
high efficiency of this converter minimizes thermal
issues. With a few modifications, this demo board will
provide the increased power and exceed the
performance objectives.
Note that the original transformer for this demo board
was designed to accommodate 4-15 series LEDs at up to
18 watts of output power. By targeting a specific number
of LEDs, the power available from the same size core
can be increased. Transformer construction details are
provided at the end of this document.
The open load protection threshold of the original board
was reduced due to lower output voltage for this LED
module. D12 was changed to 43 V.
Power switch maximum on-time capacitor C9 controls
the minimum ac line input voltage. The redesigned
transformer requires a shorter maximum on-time at this
power level. C9 was changed to 390 pF.
High power factor single stage converters generally have
no energy storage in the primary side circuit. As such,
storage is required on the secondary side and typically in
the form of capacitance in parallel with the LED load.
Ripple current is nearly sinusoidal at twice the applied ac
input frequency. The ripple amplitude is inversely
proportional to the total capacitance, that is, increasing
the filter capacitance will reduce ripple current.
Maximum forward current for this LED is 1050 mA.
Subtracting the target output current of 700 mA nets a
difference of 350 mA. Ripple current must therefore be
limited to 350 mA peak or 700 mA peak-to-peak to stay
within the manufacturers rating.
Two 470 µF capacitors were used in order to maintain
the low profile design. Testing shows this capacitance
results in ripple current of up to 480 mA peak-to-peak
with 100 V ac 60 Hz input as shown in Figure 1. The zero
reference is indicated on the first horizontal gradicule.
The output current sense resistor R29 was reduced from
0.2 ohms to 0.1 ohms to provide the required 700 mA
average output current. Two resistors were connected in
parallel for thermal spreading.
Converter startup time is controlled by the bias capacitor
C8 and the startup resistors. For this application, the
startup resistors R12 and R13 were increased in value to
reduce dissipation. This increases the converter startup
time somewhat.
June 2012, Rev. 0
Figure 1: LED ripple current
The power switching FET was changed to a higher
current device to support the increased output power
level. Current sense resistor R20 was reduced in value
due to higher primary current. In addition, the output
rectifier was changed to a Schottky type to reduce power
loss and increase efficiency.
Increased power level means the input filter must support
more switching current. The filter capacitors were
increased to minimize ripple voltage and maintain
compliance with conducted EMI limits. Capacitors C1
and C2 were increased to 100 nF and C4 was increased
to 220 nF.
High power factor is maintained by operating in critical
conduction mode (CrM). In the case of the NCL30000,
this is accomplished with a constant on-time architecture.
Details of operation can be found in Application Note
AND8451. Moreover, line harmonics in compliance with
JIS/EN61000-3-2 Class C are easily met, as shown in
Figure 2.
Power factor and Total Harmonic Distortion of input
current are shown in Figure 3. PF exceeds the target
value and for operation below 140 V ac is above 0.99.
Efficiency over the input line range is shown in Figure 4.
For the range of 115 to 230 V ac, efficiency is well above
target being greater than 88%. Note that the LED current
remains virtually unchanged over the entire input voltage
range.
A scan of conducted emissions shows greater than 6 dB
of margin for the CISPR 22 Class B limits. See Figure 5.
A bill of materials is provided in Figure 6. The highlighted
components have been changed from the standard demo
board. Details on power transformer construction are
provided at the end of this document.
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2
DN05031/D
1
F1
100nF
C1
2
1
Zero
1 amp
R1
D7
BAW56
R10
L1
27mH
3
4
L2
R2
800uH
5K6
C2
100nF
R3
L3
D1
MRA4007
D3
D4
V300LA4
RV1
MRA4007
5K6
D2
800uH
R5
MRA4007
Not Fitted
R15
C8
10uF
MRA4007
R12
Q2
100K
R13
100K
R11
100K
MMBTA06
100K
R17
100
1
2
3
4
C9
390pF
C3
MFP
R4
C4
GND
DRV
Vcc
220nF
U1
Comp
Ct
ZCD
10pF
CZCD
NCL30000
CS
Not Fitted
J1-1
Line
J1-2
1
Neutral
R8
C7
6.2K
R14
D8
4.7K
C6
1nF
D9
MMBZ5245
15V
BZX84C5V1
Q1
5.1V
MMBTA06
T
10uF
R9
6.2K
RT1
Not Fitted
8
7
6
5
C5
4700 pF
D5
ES1M
D6
BAS21
R16
47K
47K
R6
R7
47K
Q3
10
100
SPP06N80
R19
R18
R20
0.25 OHM
T1A
T1B
T1C
T1D
+
D10
C11
470uF
4.7 nF
T1E
C10
U2
PS2561L_1
+
MBR20200
C12
470uF
R21
22K
D11
BZX84C5V6
5.6V
R22
1K
C13
100nF
Q4
MMBTA06
R23
1K
D12
BZX84C43
43V
D13
8
R25
1K
R26
16K
R27
C14
200
3
2
100pF
IN1+
IN1-
4
5
6
U3
VCC
IN2+
IN2GND
R28
1
7
OUT1
OUT2
470
BAW56
C15
LM2904
Q5
220nF
MMBTA06
R24
47K
U4
TL431A
0.2 ohm
R29 0.2 ohm
R29A
R30
24K
R31
C16
100nF
24K
1
J2-1
LED Anode
LED Cathode
J2-2
1
3
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June 2012, Rev. 0
1
2
4
3
Not Fitted
DN05031/D
Schematic
Harmonic Current Percentage of
Fundametal (%)
30
25
20
15
10
Limit (%)
Measured (%)
5
0
2
3
5
7
9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39
Harmonic
Figure 2: EN61000-3-2 Class C Input Current Harmonic Test
(Vin=230 Vac, 50 Hz, Iout =704 mA @36.1V)
Figure 3: Power Factor and THDi
June 2012, Rev. 0
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4
DN05031/D
Figure 4: Efficiency and Line Regulation
Figure 5: Conducted EMI Signature (Average Scan)
June 2012, Rev. 0
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5
DN05031/D
Designator
Value
C1, C2
C3
C4
C5
C6 C8
C7
C9
CZCD
C10
C11 C12
C13
C14
C15
C16
D1 D2 D3 D4
D5
D6
D7 D13
D8
D9
D10
D11
D12
F1
J1, J2
L1
L2,L3
100nF
Q1 Q2 Q4 Q5
Q3
R1
R2,R3
R4 R5
R6 R7
R11 R15
R12 R13
R9 R10
R14
R16 R24
R17 R18
R19
R20
R21
R22 R23 R25
R26
R27
R28
R29
R29A
R30 R31
RT1
RV1
U1
U2
U3
U4
T1
Description
300 VAC X1 Polyester Film
Not Fitted
220nF
250/275VAC Polyester Film
4700 pF
Ceramic 2000V Y5U
10uF
50V Electrolytic, 5mm dia
1nF
50V Ceramic X7R
390pF
50V Ceramic C0G,NPO
10pF
50V Ceramic C0G,NPO
4.7 nF
250VAC Y5U X1Y1 (LS=10mm)
470uF
63V Aluminum Electrolytic Y5U
100nF
25V Ceramic X7R
100pF
50V Ceramic COG,NPO
220nF
25V Ceramic X7R
100nF
100V Ceramic X7R
MRA4007 Rectifier,1000V,1A
ES1M
Fast Rectifier 1A 1000V
BAS21
250V,200mA
BAW56
70V,200MA
BZX84C5V1 5.1V ZENER
MMBZ5245 15V ZENER
MBR20200 Schottky, 200V 20A
BZX84C5V6 5.6V ZENER
BZX84C43 43V ZENER
Slow Blow 1A TE5 Series
Screw Connector (0.2" Pitch)
27mH
Common Mode Choke
800uH
Shielded radial inductor
MMBTA06
SPP06N80
0 ohm
5K6
NPN, 80V, 500mA
N-Channel 800V,6A, 0.9R
Wire Jumper
1/10W
Not Fitted
47K
1/4W
100K
1/10W
100K
1/4W
6K2
1/10W
4K7
1/10W
47K
1/10W
100
1/10W
10
1/10W
0.25
1/4W
22K
1/4W
1K
1/10W
16K
1/10W
200
1/10W
470
1/10W
0.2
1/4W
0.2
1/4W
24K
1/10W
PRF21BC
PTC 470 OHM 85C
V300LA4P 300V 25 Joule (LS= 7mm)
NCL30000 Single Stage PFC LED Driver
PS2561L_1 80V, 50mA
LM2904
Dual Op Amp
TL431A
Programmable Reference
XFMR
Transformer, EFD25, 25 watt
June 2012, Rev. 0
Part Number
Footprint
Manufacturer
Box
Panasonic
Box
Radial Disc
Radial
0603 SMD
0603 SMD
0603 SMD
Radial
Radial
0603 SMD
0603 SMD
1206 SMD
1206 SMD
SMA
SMA
SOT23
SOT23
SOT23
SOT23
TO-220
SOT23
SOT23
Axial
Through Hole
Through Hole
Through Hole
Panasonic
AVX
Panasonic
Panasonic
Murata
Murata
Panasonic
Panasonic
Panasonic
Panasonic
Panasonic
Panasonic
ON Semiconductor
Micro Commercial
ON Semiconductor
ON Semiconductor
ON Semiconductor
ON Semiconductor
ON Semiconductor
ON Semiconductor
ON Semiconductor
Littelfuse
Weidmuller
Wurth Midcom
Renco
ECQ-U2A224ML
5SS472SBHCA
EEU-EB1H100S
ECJ-1VB1H102K
GRM1885C1H391JA01D
GRM1885C1H1000JA01D
CD16-E2GA472MYNS
ECA-1JHG471
ECJ-1VB1E104K
ECJ-1VC1H101J
ECJ-3VB1E224K
ECJ-3YB2A104K
MRA4007T3
ES1M
BAS21LT1G
BAW56LT1G
BZX84C5V1LT1G
MMBZ5245BLT1
MBR20200CTG
BZX84C5V6LT1G
BZX84C43LT1G
3691100044
1716020000
7446620027
RL-8054-3-821KR38-S
SOT23
TO-220
0603 SMD
ON Semiconductor
Infineon
Panasonic
MMBTA06LT1G
SPD06N80C3
ERJ-3GEYJ562V
1206 SMD
0603 SMD
1206 SMD
0603 SMD
0603 SMD
0603 SMD
0603 SMD
0603 SMD
1206 SMD
1206 SMD
0603 SMD
0603 SMD
0603 SMD
0603 SMD
1206 SMD
1206 SMD
0603 SMD
0603 SMD
Radial
SOIC8
SMT4
SOIC8
SOIC8
EFD25
Panasonic
Panasonic
Panasonic
Panasonic
Panasonic
Panasonic
Panasonic
Panasonic
Yageo
Panasonic
Panasonic
Panasonic
Panasonic
Panasonic
Rohm Semi
Rohm Semi
Panasonic
Murata
Littelfuse
ON Semiconductor
NEC Electronics
ON Semiconductor
ON Semiconductor
Custom
ERJ-8GEYJ473V
ERJ-3EKF1003V
ERJ-8GEYJ104V
ERJ-3EKF6201V
ERJ-3EKF4701V
ERJ-3EKF4702V
ERJ-3EKF1000V
ERJ-3EKF10R0V
PT1206FR-070R25L
ERJ-8GEYJ223V
ERJ-3EKF1001V
ERJ-3EKF1602V
ERJ-3EKF2000V
ERJ-3EKF4700V
MCR18EZHFLR200
MCR18EZHFLR200
ERJ-3EKF2402V
PRF18BE471QB1RB
V300LA4P
NCL30000DR2G
PS2561L-1
LM2904DR2G
TL431ACDG
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ECQ-U3A104MG
6
DN05031/D
1
1
© 2012 ON Semiconductor.
Disclaimer: ON Semiconductor is providing this design note “AS IS” and does not assume any liability arising from its use; nor
does ON Semiconductor convey any license to its or any third party’s intellectual property rights. This document is provided only to
assist customers in evaluation of the referenced circuit implementation and the recipient assumes all liability and risk associated
with its use, including, but not limited to, compliance with all regulatory standards. ON Semiconductor may change any of its
products at any time, without notice.
Design note created by Jim Young, e-mail: [email protected]
June 2012, Rev. 0
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7