cd00256065

AN3105
Application note
48 V - 130 W high efficiency converter with PFC for LED street
lighting applications - European version
By Claudio Spini
Introduction
Nowadays, LEDs are becoming ever more popular, thanks to their particular characteristics,
such as high efficiency and long life, and therefore they are pushing the innovation of current
lamp types and strongly contributing to reducing the energy consumption for internal or
external lighting. This is also the case in street lighting applications, where higher efficiency
and long life are vital for reducing costs.
For these reasons a street lighting power supply designed to power an LED lamp must have
high efficiency and at least a similar lifetime, in order to guarantee the maintenance free
operation required by these kinds of applications.
This application note describes the characteristics and features of a 130 W demonstration
board (EVL130W-SL-EU), tailored on an LED power supply specification for street lighting.
The circuit is composed of two stages; a front-end PFC using the L6562AT and an LLC
resonant converter based on the L6599AT.
The peculiarities of this design are; very high efficiency, extended European input mains
range (177-277 VAC) operation, and long term reliability.
Because reliability (MTBF - “Mean Time Between Failures”) in power supplies is typically
affected by electrolytic capacitors and their typical high failure rate, unless using very
expensive types, this board offers a very innovative design approach as the board doesn't
implement any electrolytic capacitors, which are replaced by film capacitors from EPCOS.
Component de-rating has also been carefully applied during the design phase, decreasing
the component stress as recommended by MIL-HDBK-217D. The number of components,
thanks to the use of the new L6562AT and L6599AT devices, has also been minimized,
therefore increasing the MTBF and optimizing the total component cost. Thanks to the high
efficiency achieved no heatsinks are required. The resonant stage power components are
SMT, like most of the passive components, therefore decreasing production costs.
The board also has protections in case of overload or short-circuit, open-loop by each stage,
or input overvoltage. Because of the particular application, all protections, in the case of
intervention, are auto-restart.
Figure 1.
September 2012
EVL130W-SL-EU: 130 W SMPS for LED street lighting applications
Doc ID 16774 Rev 2
1/30
www.st.com
Contents
AN3105
Contents
1
Main characteristics and circuit description . . . . . . . . . . . . . . . . . . . . . 4
1.1
Power Factor corrector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2
Resonant power stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3
Startup sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.4
Output voltage feedback loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.5
L6599AT overload and short-circuit protection . . . . . . . . . . . . . . . . . . . . . . 6
1.6
Overvoltage and open-loop protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2
Efficiency measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3
Input current harmonics measurement . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4
Functional check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1
PFC circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.2
Half-bridge resonant LLC circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.3
Dynamic load operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.4
Overcurrent and overvoltage protection . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.5
Converter startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.6
Thermal map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5
Conducted emission pre-compliance test: peak measurement . . . . . 19
6
Bill of material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
7
PFC coil specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8
Transformer specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
9
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2/30
Doc ID 16774 Rev 2
AN3105
List of figures
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
Figure 13.
Figure 14.
Figure 15.
Figure 16.
Figure 17.
Figure 18.
Figure 19.
Figure 20.
EVL130W-SL-EU: 130 W SMPS for LED street lighting applications. . . . . . . . . . . . . . . . . . 1
EVL130W-SL-EU demonstration board: electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . 7
EVL130W-SL-EU demonstration board efficiency diagrams . . . . . . . . . . . . . . . . . . . . . . . . 8
EVL130W-SL-EU demonstration board: compliance to EN61000-3-2 Class-C standard . . 9
EVL130W-SL-EU demonstration board: input current waveform at 230 V - 50 Hz - 130 W
load and 65 W load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
EVL130W-SL-EU demonstration board: Power Factor and Total Harmonic Distortion vs.
load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
EVL130W-SL-EU demonstration board: PFC stage and L6562AT waveforms at 230 V 50 Hz - full load – detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
EVL130W-SL-EU demonstration board: primary and secondary side resonant stage
waveforms at 230 V - 50 Hz - full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
EVL130W-SL-EU demonstration board: high and low frequency ripple on output voltage at
230 V - 50 Hz - full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
EVL130W-SL-EU demonstration board: output voltage variation driving a CC LED converter
- PWM = 90% and PWM = 15% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
EVL130W-SL-EU demonstration board: short-circuit at 230 VAC - 50 Hz - full load and open
loop protection intervention at 20 W load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
EVL130W-SL-EU demonstration board: startup at 230 VAC - 50 Hz - full load . . . . . . . . . 16
Thermal map at 230 VAC - 50 Hz - full load - PCB top side . . . . . . . . . . . . . . . . . . . . . . . . 17
Thermal map at 230 VAC - 50 Hz - full load - PCB bottom side . . . . . . . . . . . . . . . . . . . . . 18
CE peak measure at 230 VAC and full load - phase wire . . . . . . . . . . . . . . . . . . . . . . . . . . 19
CE peak measure at 230 VAC and full load - neutral wire . . . . . . . . . . . . . . . . . . . . . . . . . 19
PFC coil electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
PFC coil mechanical aspect(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Transformer electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Transformer overall drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
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Main characteristics and circuit description
1
AN3105
Main characteristics and circuit description
The main features of the SMPS are:
1.1
●
Extended European input mains range: 177 to 277 VAC - frequency 45 to 55 Hz
●
Output voltage: 48 V at 2.7 A
●
Long-life electrolytic capacitors are not used
●
Mains harmonics: acc. to EN61000-3-2 Class-C
●
Efficiency at full load: better than 90%
●
EMI: according to EN55022-Class-B
●
Safety: double insulation, according to EN60950, SELV
●
Dimensions: 75 x 135 mm, 30 mm components maximum height
●
No heatsinks needed
●
PCB: single side, 35 µm, FR-4, mixed PTH/SMT
Power Factor corrector
The PFC stage, working in transition mode, acts as a pre-regulator and powers the resonant
stage with the output voltage of 450 V. The PFC power topology is a conventional boost
converter, connected to the output of the rectifier bridge D3. It is completed by the coil L1,
manufactured by MAGNETICA, the diode D2 and the capacitors C5, C6, and C7 in parallel.
The PFC output capacitors are film type, 5 µF - 800 V, manufactured by EPCOS. Using film
capacitors to replace the typical electrolytic capacitors considerably increases the MTBF of
the board.
The boost switch is represented by the Power MOSFET Q2. The board is equipped with an
input EMI filter necessary to filter the commutation noise coming from the boost stage. The
PFC implements the L6562AT controller, a small and inexpensive controller which is
guaranteed for operation over a wide temperature range.
At startup, the L6562AT is supplied by the startup resistors R5, R8, and R13 charging the
capacitor C13; once the PFC begins switching, a charge pump connected to the auxiliary
winding of the PFC inductor L1 supplies both PFC and resonant controllers via a small
linear regulator realized by Q1. Once both stages have been activated, the controllers are
also supplied by the auxiliary winding of the resonant transformer, assuring correct supply
voltage during all load condition operations. The L1 auxiliary winding is also connected to
the L6562AT pin #5 (ZCD) through the resistor R18. Its purpose is to provide the information
that L1 has demagnetized, needed by the internal logic to trigger a new switching cycle. The
PFC boost peak current is sensed by resistor R34 in series to the MOSFET source; the
signal is fed into pin #4 (CS) of the L6562AT, via the filter R27 and C16.
The dividers R7, R12, R14, and R22 provide the information on the instantaneous mains
voltage to the L6562AT multiplier which is used to modulate the peak current of the boost.
The resistors R2, R6, R9 with R15 and R16 are dedicated to sensing the output voltage and
feed, to the L6562AT, the feedback information necessary to keep the output voltage
regulated. The components C11 and R20 (C12 is shorted) make up the error amplifier
compensation network necessary to keep the required loop stability.
4/30
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AN3105
1.2
Main characteristics and circuit description
Resonant power stage
The down-stream converter is a resonant LLC half-bridge stage working with 50 percent
fixed duty cycle and variable frequency. It implements the ST L6599AT, integrating all
functions necessary to properly control the resonant topology.
The resonant transformer, manufactured by MAGNETICA, uses the integrated magnetic
approach, so the leakage inductance is used for resonant operation of the circuit. Therefore,
no external, additional coil is needed for the resonance. The transformer secondary winding
configuration is the typical centre tap, using a couple of type STPS10150CG power Schottky
rectifiers. The output capacitors are film type, 4.7 µF - 63 V from EPCOS. Like for the PFC
stage, using film capacitors allows to increase considerably the MTBF of the board.
A small LC filter has been added on the output, in order to filter the high frequency ripple.
D21, D22, and R55 implement a voltage controlled bleeder; in the case of no-load operation
of the SMPS, this circuit provides a bleeder limiting the increase of output voltage, but not
affecting efficiency during normal operation. Please note that the converter has not been
designed to work in this condition and therefore its mains consumption is not optimized
(~3 W).
1.3
Startup sequence
The PFC acts as master and therefore starts first; the resonant stage operates only if the
PFC is delivering the nominal output voltage to prevent the resonant converter from working
with a too low input voltage which can cause incorrect capacitive mode operation. Therefore
both stages are designed to work according to this sequence.
For correct sequencing, the L6599AT makes use of the LINE pin (#7) to sense the PFC
output voltage via a resistor divider. The L6599AT LINE pin (#7) has an internal comparator
which has a hysteresis allowing the turn-on and turn-off voltage to be set independently. At
startup, the LLC stage starts once the PFC output voltage reaches ~ 430 V, while the turnoff threshold has been set to ~ 330 V.
1.4
Output voltage feedback loop
The output voltage is kept stable by means of a feedback loop implementing a typical circuit
using a TS2431 to modulate the current in the optocoupler diode.
On the primary side, R43 - connecting pin RFMIN (#4) to the optocoupler's phototransistor allows the L6599AT oscillator frequency to be modulated, therefore keeping the output
voltage regulated. It also sets the maximum switching frequency at about 130 kHz. R42,
which connects the same pin to ground, sets the minimum switching frequency. The R-C
series R37 and C24 sets both soft-start maximum frequency and duration.
All demonstration boards implement the voltage loop circuitry described above but in case
a current loop is also required it can be achieved by implementing the following modifications:
●
Replace R30 and R31 0R0 Ω resistors with sensing resistors, 0R033 and 0R039
respectively, both 0805
●
Populate on PCB U4 and the relevant components reported on the schematic as N.M.:
C36 = 1N0-0805; C37 = 100NF-0805; R51 = 15R-0805; R56 = 1K0-0805; R61 =22K1206; C41 = 2N2-0805; U5 = SEA05TR
●
Remove the TS2431AILT
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Main characteristics and circuit description
AN3105
With these modifications the circuit is able to keep the output current constant at 2.7 A down
to an output voltage value of around 30 V. This function can be used to optimize the voltage
drop and power dissipation in case current linear regulators are used to regulate the current
flowing in each LED strip. In case the output current is lower than the current loop setpoint,
the voltage loop takes over the operation regulating the output voltage at its nominal value,
like using the TS2431AILT.
1.5
L6599AT overload and short-circuit protection
The current flowing into the primary winding, proportional to the output load, is sensed by
the lossless circuit C34, R53, D19, D18, R57, and C35 and it is fed into the ISEN pin (#6) of
L6599AT. In the case of overcurrent, the voltage on the pin overpasses an internal threshold
(0.8 V), triggering a protection sequence. The capacitor (C21) connected to the DELAY pin
(#2) is charged by an internal 150 µA current generator. If the voltage on the pin reaches
2 V, the soft-start capacitor is completely discharged so that the switching frequency is
pushed to its maximum value. As the voltage on the pin exceeds 3.5 V the IC stops
switching and the internal generator is turned off, so that the voltage on the DELAY pin
decays because of the external resistor connected between the pin and GND. The L6599AT
is soft-restarted as the voltage drops below 0.3 V. In this way, under short-circuit conditions,
the converter works intermittently with low input average power, limiting the stress of
components during shorts.
1.6
Overvoltage and open-loop protection
Both circuit stages, PFC and resonant, are equipped with their own overvoltage protections.
The L6562AT PFC controller implements an overvoltage protection against the output
voltage variation due to the poor bandwidth of the error amplifier, happening in the case of
transients. Unfortunately it cannot protect the circuit in the case of a feedback loop failure
such as disconnection or deviation from the nominal value of the feedback loop divider. In
the case where a similar failure condition is detected, the L6599AT pin DIS (#8) stops the
operation and also stops the PFC operation by means of the L6599AT pin PFC_STOP (#9)
connected to the L6562AT pin INV (#1). The converter operation is latched until the VCC
capacitors are discharged, then a new startup sequence takes place automatically and the
converter resumes operation if the failure is removed or a new sequence is triggered. The
same sequence occurs also in the case of input voltage transients which may damage the
converter.
The DIS pin is also used to protect the resonant stage against loop failures. The Zener
diode D17 detects the auxiliary voltage generated by the LLC transformer. In the case of
loop failure, it conducts, and voltage on the DIS pin exceeds the internal threshold, latching
off the device. The L6562AT operation is also stopped by the PFC_STOP pin as in the
previous case, and after some time has elapsed the circuit restarts.
6/30
Doc ID 16774 Rev 2
FUSE T4A
F1
R47
VCC
RX2
R22
Doc ID 16774 Rev 2
1
1
C15
15 nF
2
3
Z1
1
2
N. M.
R49
R42
C24
N. M.
R44
5
6
7
R37
VCC
ZCD
GND
GD
8
C13
220 nF
C32
R43
C9
10 nF
9
11
R52
1
2
2
1
8
7
6
5
R33
N. M.
JUMPER
D23/JPX9
DIS
LINE
ISEN
STBY
RFMIN
CF
1
PFC-STOP
GND
LV
CC
V
NC
OUT
HVG
VBOOT
R21
D7
BZV55-B15
R23
DELAY
CSS
D1
1N4007
R11
3
L6599AT
U2
D9
LL4148
C25 3
470 pF 4
D14
R32
R18
D8
LL4148
Q1
BC847C
C10
D4
LL4148
5
3
L1
1974.0001
D5
LL4148
R3
D17
BZV55-B24
10 nF
C33
C26
4.7 nF
LL4148
R36
C21
220 nF
R27
R38
R13
R8
R5
C4
470 nF-X2
VCC
C31
220 nF
R1
MULT
CS
U1
R16
_
L6562AT
COMP
INV
Q3
3
N. M.
VIN
~
C16
220 pF
4
3
2
1
R15
D10
Q7
BC847C
D3
GBU8J
C3
470 nF-X2
N. M.
R20
C11
220 nF
C12
4
PCB rev. 0.2
3
C2
470 nF-X2
Q8
2 BC847C
3
R45
R14
R12
R7
177-277 VAC
1
2
L2
2019.0002
1
R34
9
10
11
12
13 VCC
14
15
C22
100 nF
16
3
C30
Q2
2 STF22NM60N
D6
LL4148
D2
STTH3L06U
D24
LL4148
220 nF
R26
VIN
R39
R57
R46
1
1
C5
C6
C40
D19
LL4148
RX1
R53
3 Q4
STD10NM60N
2
3 Q5
STD10NM60N
2
D18
LL4148
D13
LL4148
R19
R17
R24
R10
D16
LL4148
C35
R25
R9
R6
R2
R4
C34
R59
220 pF
D20
STPS1L60A
GB6
C7
15 nF
C20
13
12
14
10
8
9
11
REV. 0.9
U3
3
4
R62
2
1
2
1
C18
C39
470 nF
N. M.
R54
R60
R58
R41
3
U5
TS2431AILT
C38
R50
D22
D21
C41
R61
1
N. M.
3
N. M. 2
R56
N. M.
R51
N. M.
Vctrl
Ictrl
OUT
4
5
I.sense VCC 6
GND
1
2
N.M.
C36
C37
N. M.
48 V at 2.7 A
100 nF
C19
J2
MKDS 1,5/ 2-5,08
U4
SEA05 - N. M.
R31
R30
L3
R55
R29
N. M.
BZV55-B24 BZV55-B24
Q6
BC847C
C17
BZV55-B24
D15
D11
STPS10150CG
D12
STPS10150CG
C27
220 nF
SFH617A-2X009
7
6
4
2
T1
1860.0013
C8
2.2 nF - Y1
C1
2.2 nF - Y1
Figure 2.
2
RV1
300 VAC
MKDS 1,5/ 3-5,08
~
3
+
J1
AN3105
Main characteristics and circuit description
EVL130W-SL-EU demonstration board: electrical diagram
AM00868
7/30
Efficiency measurement
2
AN3105
Efficiency measurement
Table 1 shows the overall efficiency, measured at 230 VAC - 50 Hz with different loads.
At 230 VAC and full load the overall efficiency is 93.85%, making this design suitable for high
efficiency power supplies. The efficiency has been measured at 25%, 50%, 75%, and 100%,
the average efficiency calculated according to the ES-2 standard is 91.56%.
Table 1.
EVL130W-SL-EU demonstration board: overall efficiency vs. load
230 V-50 Hz
Load
VOUT [V]
IOUT [A]
POUT [W]
PIN [W]
Efficiency [%]
25% load
47.59
0.682
32.46
37.14
87.39%
50% load
47.55
1.37
65.14
70.89
91.89%
75% load
47.54
2.00
95.08
102.1
93.12%
100% load
47.54
2.74
130.26
138.8
93.85%
Average efficiency
91.56%
The measured output voltage at different load conditions is reported in Table 1. As seen, the
voltage is very stable over all the output load range.
The measured efficiency is shown on the lefthand side of the graph in Figure 3, while on the
righthand side of Figure 3 the efficiency, at maximum load and at minimum, nominal, and
maximum AC input voltage, is reported.
Figure 3.
EVL130W-SL-EU demonstration board efficiency diagrams
%FFICIENCYVS6!#
%FFICIENCY
%FFICIENCY
%FFICIENCYVSLOAD
,OAD
8/30
6!#;6RMS=
Doc ID 16774 Rev 2
!-
AN3105
Input current harmonics measurement
3
Input current harmonics measurement
One of the main purposes of a PFC pre-conditioner is the correction of input current
distortion, decreasing the harmonic contents below the limits of the relevant regulations.
Therefore, this demonstration board has been tested according to the European standard
EN61000-3-2 Class-C relevant to lighting equipment, at full load and nominal input voltage
mains. Measurement results are in Figure 4 - on the lefthand side.
The circuit shows its ability to reduce the harmonics, also well below the limits of
EN61000-3-2 Class-C regulation, not only at full load but also at significant lower load; on
the righthand side of Figure 4 the input current harmonics measurement at light load
(minimum input power to be compliant with the above mentioned rule is 25 W) shows that
even if the power supply is working out of its typical operating region it is still compliant with
the EN61000-3-2 Class-C limits.
Figure 4.
EVL130W-SL-EU demonstration board: compliance to EN61000-3-2 Class-C standard
(ARMONICCURRENT;!=
(ARMONICCURRENT;!=
(ARMONICORDER;N=
(ARMONICORDER;N=
-EASUREDVALUE
%.#LASS#LIMITS
!-
VIN = 230 VAC - 50 Hz, POUT = 130 W
THD = 6.85%, PF = 0.981
VIN = 230 VAC - 50 Hz, PIN = 26.7 W
THD = 10.3%, PF = 0.753
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Input current harmonics measurement
AN3105
For user reference, waveforms of the input current and voltage at nominal input voltage
mains full load and 50% load conditions are given in Figure 5.
Figure 5.
EVL130W-SL-EU demonstration board: input current waveform at 230 V - 50 Hz
- 130 W load and 65 W load
CH1: VIN AC
CH1: VIN AC
CH4: I_AC
CH4: I_AC
The “Power Factor” (PF) and the “Total Harmonic Distortion” (THD) versus load variations
have also been measured and the results are given in Figure 6. As seen, the Power Factor
remains close to unity and the Total Harmonic Distortion is very low.
Figure 6.
EVL130W-SL-EU demonstration board: Power Factor and Total Harmonic Distortion
vs. load
4($VSLOAD
4($
0OWER&ACTOR
0OWER&ACTORVSLOAD
,OAD
,OAD
!-
10/30
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AN3105
Functional check
4
Functional check
4.1
PFC circuit
On the lefthand side of Figure 7, some waveforms relevant to the PFC stage have been
captured; the envelope of CS pin (#4) waveforms of the L6562AT is in phase with the MULT
pin (3#) and has the same sinusoidal shape, demonstrating the correct functioning of the
PFC stage. It is also possible to measure the peak-to-peak value of voltage ripple over
imposed to the PFC output voltage; this is due to the low value of the PFC output capacitors.
On the righthand side of Figure 7 the details of some waveforms at switching frequency are
given.
Figure 7.
EVL130W-SL-EU demonstration board: PFC stage and L6562AT waveforms at 230 V 50 Hz - full load – detail
CH2: VOUT PFC
CH4: MULT
4.2
CH3: CS
CH3: CS
CH1: Vdrain_Q2
CH4: ZCD
CH2: VOUT PFC
Half-bridge resonant LLC circuit
Some waveforms relevant to the resonant stage during steady-state operation are given in
the following pages. The resonant stage switching frequency is about 100 kHz, in order to
have a good trade off between transformer losses and dimensions.
The LLC converter has been designed to operate at nominal voltage and full load at the
resonance frequency, but due to the PFC output voltage ripple at twice the mains frequency
it is driven slightly above and below the resonant tank frequency, according to the
instantaneous value of PFC output voltage.
In Figure 8 (on the lefthand side) some waveforms relevant to the resonant stage ZVS
operation are shown; it is possible to see that both MOSFETs are turned on when resonant
current is flowing through their body diodes and therefore drain-source voltage is almost
zero, achieving good efficiency because the turn-on losses are negligible. The HB MOSFET
voltage de-rating and low operating temperature allow the board MTBF to be increased.
The current flowing in the resonant tank is sinusoidal; in Figure 8 it is possible to appreciate
a slight asymmetry of operating modes by each half portion of the sinewave; half cycle is
working at resonant frequency while the other is working above the resonant frequency. This
Doc ID 16774 Rev 2
11/30
Functional check
AN3105
is due to a small difference between each half-secondary leakage inductance of the
transformer reflected to the primary side, providing the two slightly different resonant
frequencies. This phenomenon is typically due to a different coupling of transformer
secondary windings and in this case it is not an issue. The slight asymmetry can also be
appreciated in Figure 8 (on the righthand side); the small ringing appearing on both
secondary rectifiers anode voltage indicates that for a short time the rectifiers are not
conducting; it demonstrates that during half cycle the circuit is working below the resonant
frequency while during the following half cycle it is working at resonance frequency.
In Figure 8 it is also possible to appreciate the rectifier operating voltage and its margin with
respect to the maximum reverse voltage (VRRM). This de-rating with respect to the rectifiers
VRRM guarantees good reliability of the output rectifiers increasing the board total MTBF.
Figure 8.
EVL130W-SL-EU demonstration board: primary and secondary side resonant stage
waveforms at 230 V - 50 Hz - full load
CH1: HB voltage
CH3: VCC
12/30
CH2: CF pin voltage
CH4: res. tank current
CH1: V_D12
CH3: VOUT
Doc ID 16774 Rev 2
CH2: V_D11
AN3105
Functional check
On the lefthand side of Figure 9 the high frequency ripple has been measured; as seen the
ripple and noise at switching frequency is very limited, thanks to the low EMI generated by
both stages. On the righthand side of Figure 9 the low frequency ripple has also been
measured. It is possible to note that the peak-to-peak value is not so low but it doesn't affect
the application, in fact the converters regulating the current flowing in each LED strip can
reject the ripple without any problem.
Figure 9.
CH3: VOUT
4.3
EVL130W-SL-EU demonstration board: high and low frequency ripple on output
voltage at 230 V - 50 Hz - full load
CH1: HB voltage
CH3: VOUT
Dynamic load operation
Waveforms reported in Figure 10 are relevant to the demonstration board during operation,
supplying converters dedicated to power LED strips with constant current.
In both figures it is possible to see the output voltage modulation during operation with
variable load due to the dimming of the LED current by PWM. For both measurements,
a dimming frequency of 300 Hz has been chosen.
On the lefthand side of Figure 10 the converter output current was 2.6 A and dimming duty
cycle was 90%, therefore very close to the converter nominal output power. The output
voltage in the image has two modulations; one is due to the rejection of the PFC output
voltage ripple already measured in Figure 9, on the righthand side. Over imposed there is
the voltage variation due to the LED current dimming. The peak-to-peak variation is 5.37 V,
this doesn't create any problems for the load as the converters reject the modulation.
Whereas on the righthand side of Figure 10 the converter has been checked at light load, so
the peak output current was 3 A and dimming duty cycle was 15%, for an output power of
21 W. Even in this case the peak-to-peak modulation doesn't give any trouble to the downstream current regulators and the board still works correctly.
Doc ID 16774 Rev 2
13/30
Functional check
AN3105
Figure 10. EVL130W-SL-EU demonstration board: output voltage variation driving
a CC LED converter - PWM = 90% and PWM = 15%
CH1: PWM dimming signal
CH4: SMPS output current
CH2: VOUT
CH1: PWM dimming signal
CH4: SMPS output current
CH2: VOUT
It is worth clarifying that, for correct operation with LED strips, the board needs some
additional capacitors connected on the +48 V output bus. It has not been equipped with all
the capacitors necessary for correct operation with LEDs but only with minimum
capacitance to allow board operation, in order to optimize the system cost and reliability.
The additional capacitors needed are intended to be placed close to each LED strip current
regulator, therefore filtering the EMI generated by these. In several cases, in fact, the power
supply is placed at the base of the lighting pole while the LED current regulators are located
on top, in the lamp. The long wiring connection between the power supply and the
converters can act as an antenna radiating EMI. Therefore local filtering minimizes the
radiated EMI.
The capacitance to be added to the 48 V bus, for correct operation with LEDs, is around
40 µF. In order to not affect the board MTBF, using the same capacitor type already used on
the power supply board is suggested.
4.4
Overcurrent and overvoltage protection
The L6599AT is equipped with a current sensing input (pin #6, ISEN) and a dedicated
overcurrent management system. The current flowing in the resonant tank is detected and
the signal is fed into the ISEN pin. It is internally connected to a first comparator, referenced
to 0.8 V, and to a second comparator referenced to 1.5 V. If the voltage externally applied to
the pin exceeds 0.8 V, the first comparator is tripped causing an internal switch to be turned
on and discharging the soft-start capacitor C24 (CSS). Under output short-circuit, this
operation results in a nearly constant peak primary current.
With the L6599AT the designer can program externally the maximum time that the converter
is allowed to run overloaded or under short-circuit conditions. Overloads or short-circuits
lasting less than the set time do not cause any other action, and so provide the system with
immunity to short duration phenomena. If, instead, an overload condition continues,
a protection procedure is activated which shuts down the L6599AT. In the case of
continuous overload or short-circuit, it results in continuous intermittent operation with
a user defined duty cycle.
14/30
Doc ID 16774 Rev 2
AN3105
Functional check
This function is realized with the DELAY pin (#2), by means of a capacitor C21 and the
parallel resistor R32 connected to ground. As the voltage on the ISEN pin exceeds 0.8 V the
first OCP comparator, in addition to discharging CSS, turns on an internal 150 µA current
generator that via the DELAY pin charges C21. When the voltage on C21 is 3.5 V, the
L6599AT stops switching and the PFC_STOP pin (#9) is pulled low, also turning off the PFC
stage via the L6562AT pin #1 (INV). Also the internal generator is turned off, so that C21 is
now slowly discharged by R32. The IC restarts once the voltage on C21 is less than 0.3 V.
Additionally, if the voltage on the ISEN pin reaches 1.5 V for any reason (e.g. transformer
saturation), the second comparator is triggered, the L6599AT shuts down and the operation
is resumed after recycling the VCC. In this demonstration board the intervention of the
second level comparator latches the operation of the L6599AT and the PFC_STOP pin (#9)
stops the PFC. Both controllers are no longer powered by VCC and the latch is removed,
then a new startup cycle takes place. This sequence lasts until the short is removed.
On the lefthand side of Figure 11 the operation of the DELAY pin and the consequent hiccup
mode operation of the board during short-circuit operation can be seen. Thanks to the
narrow operating time, with respect to the off time, the average output current, as well as the
average primary current, are limited. This avoids converter overheating and consequent
failures. At short removal the board resumes normal operation.
Figure 11. EVL130W-SL-EU demonstration board: short-circuit at 230 VAC - 50 Hz - full load and
open loop protection intervention at 20 W load
CH1: V_OUT_PFC
CH4: DELAY pin
CH2: HB voltage
CH3: VOUT
CH1: Q1_Drain
CH4: DIS pin
CH2: HB voltage
On the righthand side of Figure 11 the operation of the demonstration board during “openloop” operation by the LLC stage is shown. The open-loop operation also provides an
increase of the auxiliary voltage which triggers the L6599AT pin #9 (DIS) protection pin via
the Zener diode D17. As a consequence, the L6599AT shuts down, stopping the operation.
The L6599AT also activates the PFC_STOP pin (#9) which also stops the PFC, therefore
both controllers are no longer powered by VCC. Once VCC drops below the UVLO the latch
is removed and a new startup cycle takes place. This sequence lasts until the open-loop is
removed.
Doc ID 16774 Rev 2
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Functional check
4.5
AN3105
Converter startup
On the lefthand side of Figure 12 the converter startup is shown. It is possible to note that at
nominal input voltage the converter begins operation in ~150 ms. This is the time needed to
charge the VCC to the L6562AT turn-on voltage. Therefore the L6562AT starts switching and
the PFC output voltage starts increasing. Once the PFC output voltage reaches the enable
level set via the L6599AT LINE pin (~ 430 V), even the LLC stage starts switching and the
output voltage rises up to the nominal level. The VCC is initially supplied by the PFC coil
charge pump, and then, once the L6599AT starts operating, the VCC is also provided by the
LLC transformer auxiliary winding. Details of converter sequencing can be found on the
righthand side of Figure 12.
Figure 12. EVL130W-SL-EU demonstration board: startup at 230 VAC - 50 Hz - full load
CH1: Q2_Drain CH2: HB voltageCH1: Q2_DrainCH2: HB voltage
CH3: L6562AT VCC CH4: VOUTCH3: L6599AT VCC pin CH4: VOUT
Figure 12 shows a correct startup of the board using an active load, with only the capacitors
for the 48 V populating the board. When powering current regulators with LEDs it is possible
that the board may show an incorrect startup, with output voltage going up and down and
the LEDs flashing. As already explained in Section 4.3: Dynamic load operation, the board
needs an additional 40 µF capacitance on the +48 V.
16/30
Doc ID 16774 Rev 2
AN3105
4.6
Functional check
Thermal map
In order to check the design reliability, a thermal mapping by means of an IR camera was
done. In Figure 13 and 14 the thermal measurements of the board, both sides, at nominal
input voltage are shown. Some pointers visible on the images have been placed across key
components. The ambient temperature during both measurements was 27 °C.
Figure 13. Thermal map at 230 VAC - 50 Hz - full load - PCB top side
Table 2.
Thermal maps reference points - PCB top side
Point
Reference
Description
A
L2
EMI filtering inductor
B
L1
PFC inductor
C
D3
Bridge rectifier
D
Q2
PFC MOSFET
E
L3
Output filter inductor
F
T1
Resonant power transformer - primary winding
G
T1
Resonant power transformer - ferrite core
H
T1
Resonant power transformer - secondary winding
Doc ID 16774 Rev 2
17/30
Functional check
AN3105
Figure 14. Thermal map at 230 VAC - 50 Hz - full load - PCB bottom side
Table 3.
Point
18/30
Thermal maps reference points - PCB bottom side
Reference
Description
A
Q4
LLC resonant HB MOSFET
B
Q5
LLC resonant HB MOSFET
C
D2
PFC output diode
D
D12
Output rectifier
E
D11
Output rectifier
Doc ID 16774 Rev 2
AN3105
5
Conducted emission pre-compliance test: peak measurement
Conducted emission pre-compliance test: peak
measurement
Figure 15 and 16 show the peak measurement of the conducted noise at full load and
nominal mains voltage. The limits on the diagrams are the EN55022 Class-B. As seen in the
diagrams, for both input wires the measurements are well below the limits.
Figure 15. CE peak measure at 230 VAC and full load - phase wire
Figure 16. CE peak measure at 230 VAC and full load - neutral wire
Doc ID 16774 Rev 2
19/30
Bill of material
AN3105
6
Bill of material
Table 4.
EVL130W-SL-EU demonstration board: bill of material
Des.
Part type/
part value
Case style/
package
Description
Supplier
C1
2N2-Y1
4.5 x 12.0
p.10 mm
Y1 safety cap. DE1E3KX222M
Murata
C10
1 µF
1206
50 V CERCAP - general purpose - X7R - 10%
TDK©
C11
220 nF
0805
16 V CERCAP - general purpose - X7R - 10%
Murata
C12
0R0
0805
SMD standard film res. - 1/8 W - 1% - 100 ppm/°C
VISHAY®
C13
10 µF
1210
25 V CERCAP - general purpose - X7R - 20%
TDK
C15
15 nF
0805
50 V CERCAP - general purpose - X7R - 10%
KEMET
C16
220 pF
0805
50 V CERCAP - general purpose - COG - 5%
KEMET
C17
4.7 µF
7.8 x 7.8
p. 5
63 V - MKT film cap. - B32529D0475M000
EPCOS
C18
4.7 µF
7.8 x 7.8
p. 5
63 V - MKT film cap. - B32529D0475M000
EPCOS
C19
100 nF
0805
100 V CERCAP - general purpose - X7R - 10%
AVX
C2
470 nF - X2
9.0 × 18.0
p.15 mm
X2 - MKP film cap. - B32922C3474K
EPCOS
C20
15 nF
DWG - 5 x 18
p.15 mm
1000 V - MKP film cap. - B32652A0153K000
EPCOS
C21
220 nF
0805
16 V CERCAP - general purpose - X7R - 10%
Murata
C22
100 nF
1206
50 V CERCAP - general purpose - X7R - 10%
KEMET
C24
4.7 µF
0805
6.3 V CERCAP - general purpose - X5R - 10%
EPCOS
C25
470 pF
0805
50 V CERCAP - general purpose - COG - 5%
EPCOS
C26
4.7 nF
0805
50 V CERCAP - general purpose - X7R - 10%
KEMET
C27
220 nF
0805
50 V CERCAP - general purpose - X7R - 10%
Murata
C3
470 nF - X2
9.0 × 18.0 p.
15 mm
X2 - MKP film cap. - B32922C3474K
EPCOS
C30
10 µF
1210
25 V CERCAP - general purpose - X7R - 20%
TDK
C31
220 nF
0805
16 V CERCAP - general purpose - X7R - 10%
Murata
C32
220 nF
0805
16 V CERCAP - general purpose - X7R - 10%
Murata
C33
10 nF
0805
50 V CERCAP - general purpose - X7R - 10%
KEMET
C34
220 pF
1206
1 KV high voltage CERCAP - X7R - 10%
AVX
C35
220 nF
0805
16 V CERCAP - general purpose - X7R - 10%
Murata
C36
N. M.
0805
Not mounted
C37
N. M.
0805
Not mounted
C38
N. M.
0805
Not mounted
20/30
Doc ID 16774 Rev 2
AN3105
Bill of material
Table 4.
Des.
EVL130W-SL-EU demonstration board: bill of material (continued)
Part type/
part value
Case style/
package
Description
Supplier
C39
470 nF
0805
25 V CERCAP - general purpose - X7R - 10%
KEMET
C4
470 nF - X2
9.0 × 18.0
p.15 mm
X2 - MKP film cap. - B32922C3474K
EPCOS
C40
10 µF
2220
50 V - CERCAP - general purpose - X7R - 20%
TDK
C41
N. M.
0805
Not mounted
C5
5 µF
14 × 31.5
p.27.5 mm
800 V - MKP film cap. - B32774D8505K000
EPCOS
C6
5 µF
14 × 31.5
p. 27.5 mm
800 V - MKP film cap. - B32774D8505K000
EPCOS
C7
5 µF
14 × 31.5
p. 27.5 mm
800 V - MKP film cap. - B32774D8505K000
EPCOS
C8
2.2 nF - Y1
4.5 x 12 p.10
mm
Y1 safety cap. DE1E3KX222M
Murata
C9
10 nF
1206
100 V CERCAP - general purpose - X7R - 10%
KEMET
D1
1.4007 nF
DO-41
General purpose rectifier
VISHAY
D10
N. M.
SOD-80
Not mounted
D11
STPS10150CG D2PAK
Power Schottky rectifier
STMicroelectronics™
D12
STPS10150CG D2PAK
Power Schottky rectifier
STMicroelectronics
D13
LL4148
SOD-80
Fast switching diode
VISHAY
D14
LL4148
SOD-80
Fast switching diode
VISHAY
D15
BZV55-B24
SOD-80
Zener diode
VISHAY
D16
LL4148
SOD-80
Fast switching diode
VISHAY
D17
BZV55-B24
SOD-80
Zener diode
VISHAY
D18
LL4148
SOD-80
Fast switching diode
VISHAY
D19
LL4148
SOD-80
Fast switching diode
VISHAY
D2
STTH3L06U
SMB
Ultrafast high voltage rectifier
STMicroelectronics
D20
STPS1L60A
SMA
Fast switching diode
STMicroelectronics
D21
BZV55-B24
SOD-80
Zener diode
VISHAY
D22
BZV55-B24
SOD-80
Zener diode
VISHAY
JPX9
JUMPER
/D23
Wire jumper
D24
LL4148
SOD-80
Fast switching diode
D3
GBU8J
STYLE GBU Single-phase bridge rectifier
DWG
VISHAY
D4
LL4148
SOD-80
Fast switching diode
VISHAY
D5
LL4148
SOD-80
Fast switching diode
VISHAY
D6
LL4148
SOD-80
Fast switching diode
VISHAY
Doc ID 16774 Rev 2
VISHAY
21/30
Bill of material
Table 4.
Des.
AN3105
EVL130W-SL-EU demonstration board: bill of material (continued)
Part type/
part value
Case style/
package
Description
Supplier
D7
BZV55-B15
SOD-80
Zener diode
VISHAY
D8
LL4148
SOD-80
Fast switching diode
VISHAY
D9
LL4148
SOD-80
Fast switching diode
VISHAY
F1
FUSE T4A
8.5 x 4 p. 5.08
Fuse 4 A - time lag - 3921400
mm
Littlefuse
J1
MKDS 1,5/
3-5,08
p. 5.08 mm
PCB term. block, screw conn., pitch 5 mm - 3 W.
PHOENIX CONTACT
J2
MKDS 1,5/
2-5,08
p. 5. 08 mm
PCB term. block, screw conn., pitch 5 mm - 2 W.
PHOENIX CONTACT
L1
1974.0001
DWG
PFC choke - 520 µH PQ26/20
MAGNETICA
L2
12 mH
DWG
CM filter 2019.0002
MAGNETICA
L3
3.3 µH - 4.7 A
Dia. 7.7
p. 5 mm
Inductor 1071.0080
MAGNETICA
Q1
BC846C
SOT-23
NPN small signal BJT
VISHAY
Q2
STF22NM60N
TO220
N-channel Power MOSFET
STMicroelectronics
Q3
N. M.
SOT-23
Not mounted
Q4
STD10NM60N
DPAK
N-channel Power MOSFET
STMicroelectronics
Q5
STD10NM60N
DPAK
N-channel Power MOSFET
STMicroelectronics
Q6
BC846C
SOT-23
NPN small signal BJT
VISHAY
Q7
BC846C
SOT-23
NPN small signal BJT
VISHAY
Q8
BC846C
SOT-23
NPN small signal BJT
VISHAY
R1
N. M.
0805
Not mounted
R10
1.2 MΩ
1206
SMD standard film res. - 1/4 W - 1% - 100 ppm/°C
VISHAY
R11
4.7 KΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R12
2.0 MΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R13
120 KΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R14
390 KΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R15
39 KΩ
0805
SMD standard film res. - 1/8 W - 1% - 100 ppm/°C
VISHAY
R16
39 KΩ
0805
SMD standard film res. - 1/8 W - 1% - 100 ppm/°C
VISHAY
R17
0Ω
1206
SMD standard film res. - 1/4 W - 1% - 100 ppm/°C
VISHAY
R18
56 KΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R19
0Ω
0805
SMD standard film res. - 1/8 W - 1% - 100 ppm/°C
VISHAY
R2
1.0 MΩ
1206
SMD standard film res. - 1/4 W - 1% - 100 ppm/°C
VISHAY
R20
680 KΩ
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R21
33 Ω
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
22/30
Doc ID 16774 Rev 2
AN3105
Bill of material
Table 4.
Des.
EVL130W-SL-EU demonstration board: bill of material (continued)
Part type/
part value
Case style/
package
Description
Supplier
R22
15 KΩ
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R23
100 Ω
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R24
1.4 MΩ
1206
SMD standard film res. - 1/4 W - 1% - 100 ppm/°C
VISHAY
R25
82 KΩ
0805
SMD standard film res. - 1/8 W - 1% - 100 ppm/°C
VISHAY
R26
15 KΩ
0805
SMD standard film res. - 1/8 W - 1% - 100 ppm/°C
VISHAY
R27
470 Ω
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R29
N. M.
1206
Not mounted
R3
10 Ω
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R30
0Ω
1206
SMD standard film res. - 1/4 W - 1% - 100 ppm/°C
VISHAY
R31
0Ω
1206
SMD standard film res. - 1/4 W - 1% - 100 ppm/°C
VISHAY
R32
270 KΩ
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R33
N. M.
2010
Not mounted
R34
0.39 Ω
2010
SMD standard film res. - 1/2 W - 5% - 250 ppm/°C
VISHAY
R36
4.7 KΩ
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R37
6.8 KΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R38
2.2 MΩ
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R39
51 Ω
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R4
1.2 MΩ
1206
SMD standard film res. - 1/4 W - 1% - 100 ppm/°C
VISHAY
R41
4.7 KΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R42
10 KΩ
0805
SMD standard film res. - 1/8 W - 1% - 100 ppm/°C
VISHAY
R43
10 KΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R44
N. M.
0805
Not mounted
R45
220 KΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R46
51 Ω
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R47
220 KΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R49
0Ω
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R5
120 KΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R50
10 KΩ
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R51
N. M.
0805
Not mounted
R52
10 Ω
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R53
100 Ω
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R54
2.2 KΩ
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R55
470 Ω
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R56
N. M.
0805
Not mounted
Doc ID 16774 Rev 2
23/30
Bill of material
Table 4.
AN3105
EVL130W-SL-EU demonstration board: bill of material (continued)
Des.
Part type/
part value
Case style/
package
Description
Supplier
R57
100 Ω
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R58
150 KΩ
0805
SMD standard film res. - 1/8 W - 1% - 100 ppm/°C
VISHAY
R59
1.5 Ω
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R6
1.0 MΩ
1206
SMD standard film res. - 1/4 W - 1% - 100 ppm/°C
VISHAY
R60
8.2 KΩ
0805
SMD standard film res. - 1/8 W - 1% - 100 ppm/°C
VISHAY
R61
N. M.
1206
Not mounted
R62
100 KΩ
0805
SMD standard film res. - 1/8 W - 5% - 250 ppm/°C
VISHAY
R7
2.0 MΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R8
120 KΩ
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
R9
1.5 MΩ
1206
SMD standard film res. - 1/4 W - 1% - 100 ppm/°C
VISHAY
RV1
300 VAC
dia. 15 x 5 p.
7.5 mm
300 V metal oxide varistor - B72214S0301K101
EPCOS
RX1
0Ω
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
RX2
0Ω
1206
SMD standard film res. - 1/4 W - 5% - 250 ppm/°C
VISHAY
T1
1860.0013
DWG - ETD34
Resonant power transformer
MAGNETICA
U1
L6562ATD
SO-8
TM PFC controller
STMicroelectronics
U2
L6599ATD
SO-16
Improved HV resonant controller
STMicroelectronics
U3
SFH617A2X009
SMD4 - 10.16
MM
Optocoupler
VISHAY
U4
SEA05 - N. M.
SOT-23-6L
CC/CV controller – not mounted
STMicroelectronics
U5
TS2431AILT
SOT-23
Programmable shunt voltage reference
STMicroelectronics
Z1
PCB REV. 0.2
24/30
Doc ID 16774 Rev 2
AN3105
7
PFC coil specifications
PFC coil specifications
General description and characteristics
●
Application type: consumer, home appliance
●
Transformer type: open
●
Coil former: vertical type, 6 + 6 pins
●
Max. temp. rise: 45 °C
●
Max. operating ambient temperature: 60 °C
●
Mains insulation: N. A.
●
Unit finishing: varnished
Electrical characteristics
●
Converter topology: boost, transition mode
●
Core type: PQ26/20-PC44 or equivalent
●
Min. operating frequency: 40 kHz
●
Typical operating frequency: 120 kHz
●
Primary inductance: 1 mH ± 10% at 1 kHz-0.25 V(a)
●
Peak primary current: 2.1 Apk
●
RMS primary current: 0.85 ARMS
Electrical diagram and winding characteristics
Figure 17. PFC coil electrical diagram
!-
a. Measured between pins #5 and #9.
Doc ID 16774 Rev 2
25/30
PFC coil specifications
Table 5.
AN3105
PFC coil winding data
Pins
Windings
Number of turns
Wire type
11 - 3
Aux.
7
0.28 mm - G2
5-9
Primary
71
Multistrand #6 x 0.20 mm - G2
●
Primary winding external insulation: 2 layers of polyester tape.
●
Aux. winding is wound on top of primary winding.
●
External insulation: 2 layers of polyester tape
●
Wire connected to pin 5 is insulated by sleeve.
Mechanical aspect and pin numbering
●
Maximum height from PCB: 22 mm
●
Coil former type: vertical, 6+6 pins (pins #1, 2, 4, 6, 7, 10, and 12 are removed)
●
Pin distance: 3.81 mm
●
Row distance: 25 mm
●
Coil former P/N: TDK BPQ26/20-1112CP
●
External copper shield: Not insulated, wound around the ferrite core and including the
coil former. Height is 8 mm. Connected to pin #3 by a soldered solid wire.
Figure 18. PFC coil mechanical aspect(1)
MAX
MAX
MAX
"OTTOMVIEW0).SIDE
1. Dimensions are in millimeters, drawing is not to scale.
Manufacturer
26/30
●
MAGNETICA, R. Volpini - Italy (www.magneticait.it)
●
Inductor P/N: 1974.0001.
Doc ID 16774 Rev 2
!-
AN3105
8
Transformer specification
Transformer specification
General description and characteristics
●
Application type: consumer, home appliance
●
Transformer type: open
●
Coil former: horizontal type, 7 + 7 pins, two slots
●
Max. temp. rise: 45 °C
●
Max. operating ambient temperature: 60 °C
●
Mains insulation: acc. With EN60950
Electrical characteristics
●
Converter topology: half-bridge, resonant
●
Core type: ETD34-PC44 or equivalent
●
Min. operating frequency: 70 kHz
●
Typical operating frequency: 100 kHz
●
Primary inductance: 770 µH ± 15% at 1 kHz - 0.25 V(b)
●
Leakage inductance: 170 µH at 100 kHz - 0.25 V(c)
Electrical diagram and winding characteristics
Figure 19. Transformer electrical diagram
02)-
3%#!
!58
3%#"
!-
b. Measured between pins 2-4.
c. Measured between pins 2-4 with only one secondary winding shorted. The difference between the two
measured leakage inductances must be < 10%.
Doc ID 16774 Rev 2
27/30
Transformer specification
Table 6.
Transformer winding data
Pins
Winding
RMS current
Number of turns
Wire type
2-4
Primary
8-10
12-14
6-7
1.
AN3105
1 ARMS
47
#30 x 0.1 mm - G2
SEC -
A(1)
0.05 ARMS
9
#60 x 0.1 mm - G2
SEC -
B4(1)
2.2 ARMS
9
#60 x 0.1 mm - G2
2.2 ARMS
3
0.28 mm - G2
Aux. (2)
Secondary windings A and B must be wound in parallel.
2. Aux. winding is wound on top of primary winding, turns are close to each other, placed on external side of
the coil former.
Mechanical aspect and pin numbering
●
Maximum height from PCB: 30 mm
●
Coil former type: horizontal, 7 + 7 pins (pins #1, #3 and #5 removed for PCB reference)
●
Pin distance: 5.08 mm
●
Row distance: 25.4 mm.
Figure 20. Transformer overall drawing
MAX
MAX
MIN
MAX
,!"%,
-ISSINGPINAND
AS0#"REFERENCE
0INSIDEVIEW
!-
1. Quotes are in millimeters, drawing is not to scale.
Manufacturer
28/30
●
MAGNETICA, R. Volpini - Italy (www.magneticait.it)
●
Transformer P/N: 1860.0013.
Doc ID 16774 Rev 2
AN3105
9
Revision history
Revision history
Table 7.
Document revision history
Date
Revision
Changes
01-Mar-2010
1
Initial release.
28-Sep-2012
2
– Modified:Table 4
– Modified:Figure 2
– Minor text changes to improve readability
Doc ID 16774 Rev 2
29/30
AN3105
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