June 2017 DocID17595 Rev 2 1/32
32
AN3233
Application note
12 V - 150 W resonant converter with synchronous rectification
using L6563H, L6599A, and SRK2000A
Claudio Spini
Introduction
This application note describes the characteristics and features of a 150 W SMPS
demonstration board (EVL150W-ADP-SR), tailored to all-in-one computer power supply
(PS) specifications.
The characteristics of this design are the very high efficiency and low consumption at light
load which make it a viable solution for applications compliant with ENERGY STAR®
eligibility criteria (EPA rev. 5.0 computer and EPA rev. 2.0 EPS). One of the key factors to
achieving high efficiency at heavy load is the SRK2000A. This synchronous rectification
(SR) driver for LLC resonant converters allows a significant decrease in secondary side
losses.
Standby consumption is very low thanks to the sleep function embedded in the SRK2000A
and the high voltage start-up circuit integrated in the L6563H. The possibility of driving the
PFC burst mode via the L6599A PFC_STOP pin dramatically boosts light load efficiency.
Additionally, a secondary sensing circuit, dedicated to driving the primary controller into
burst mode, reduces deviation of light load efficiency against resonant circuit parameter
spread, improving the repeatability of design in production volumes.
Figure 1. EVL150W-ADP-SR: 150 W SMPS demonstration board
www.st.com
Contents AN3233
2/32 DocID17595 Rev 2
Contents
1 Main characteristics and circuit description . . . . . . . . . . . . . . . . . . . . . 5
2 Efficiency measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3 Harmonic content measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4 Functional check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5 Thermal map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6 Conducted emission pre-compliance test . . . . . . . . . . . . . . . . . . . . . . 21
7 Bill of material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8 PFC coil specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9 Transformer specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
10 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
DocID17595 Rev 2 3/32
AN3233 List of figures
32
List of figures
Figure 1. EVL150W-ADP-SR: 150 W SMPS demonstration board . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. Burst mode circuit block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 3. Electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 4. Light load efficiency diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 5. Compliance with EN61000-3-2 at 230 Vac – 50 Hz, full load . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 6. Compliance with JEITA-MITI at 100 Vac – 50 Hz, full load . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 7. Resonant stage waveforms at 115 V – 60 Hz – full load . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 8. SRK2000A key signals at 115 V – 60 Hz – full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 9. High-side MOSFET ZV turn-on at 115 V – 60 Hz – full load. . . . . . . . . . . . . . . . . . . . . . . 15
Figure 10. Low-side MOSFET ZV turn-on at 115 V – 60 Hz – full load . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 11. Converter startup at 115 Vac full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 12. Converter shutdown at 115 Vac full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 13. Startup resonant current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 14. Shutdown resonant current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 15. No-load operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 16. No-load operation – detail. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 17. Transition full load to no load at 115 Vac – 60 Hz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 18. Transition no load to full load at 115 Vac – 60 Hz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 19. Short-circuit at full load and 115 Vac – 60 Hz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 20. Thermal map at 115 Vac – 60 Hz - full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 21. Thermal map at 230 Vac – 50 Hz - full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 22. Thermal map SR daughterboard - full load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 23. CE average measurement at 115 Vac and full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 24. CE average measurement at 230 Vac and full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 25. PFC coil electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figure 26. PFC coil mechanical aspect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 27. Transformer electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Figure 28. Transformer overall drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Main characteristics and circuit description AN3233
4/32 DocID17595 Rev 2
1 Main characteristics and circuit description
The main features of the SMPS are:
Input mains range: 90 ÷ 264 Vac - frequency 45 65 Hz
Output voltage: 12 V at 12.5 A continuous operation
Mains harmonics: acc. to EN61000-3-2 Class-D or JEITA-MITI Class-D
Standby mains consumption: < 0.2 W at 230 Vac
Efficiency at nominal load: > 91 % at 115 Vac
EMI: according to EN55022-Class-B
Safety: according to EN60950
Dimensions: 65 x 154 mm, 28 mm component maximum height
PCB: double side, 70 µm, FR-4, mixed PTH/SMT.
The circuit is composed of two stages: a front-end PFC using the L6563H and an LLC
resonant converter based on the L6599A and the SRK2000A, controlling the SR MOSFETs
on the secondary side. The SR driver and the rectifier MOSFETs are mounted on a
daughterboard.
The L6563H is a current mode PFC controller operating in transition mode and implements
a high voltage start-up source to power on the converter.
The L6599A integrates all the functions necessary to properly control the resonant converter
with a 50 % fixed duty cycle and working with variable frequency.
The output rectification is managed by the SRK2000A, an SR driver dedicated to LLC
resonant topology.
The PFC stage works as the pre-regulator and powers the resonant stage with a constant
voltage of 400 V. The downstream converter operates only if the PFC is on and regulating.
In this way, the resonant stage can be optimized for a narrow input voltage range.
The L6599A's LINE pin (pin 7) is dedicated to this function. It is used to prevent the resonant
converter from working with an input voltage that is too low which can cause incorrect
capacitive mode operation. If the bulk voltage (PFC output) is below 380 V, the resonant
start-up is not allowed. The L6599A LINE pin internal comparator has a hysteresis allowing
to set the turn-on and turn-off voltage independently. The turn-off threshold has been set to
300 V in order to avoid capacitive mode operation but allow the resonant stage to operate
even in the case of mains sag and consequent PFC output dip.
The transformer uses the integrated magnetic approach, incorporating the resonant series
inductance. Therefore, no external, additional coil is needed for the resonance. The
transformer configuration chosen for the secondary winding is center-tap.
On the secondary side, the SRK2000A core function is to switch on each synchronous
rectifier MOSFET whenever the corresponding transformer half-winding starts conducting
(i.e. when the MOSFET body diode starts conducting) and then switching it off when the
flowing current approaches zero. For this purpose, the IC is provided with two pins (DVS1
and DVS2) sensing the MOSFET drain voltage level.
One of the SRK2000A’s main characteristics is the ability to automatically detect light load
operation and enter sleep mode, disabling MOSFET driving and decreasing its
consumption. This function allows great power saving at light load with respect to
benchmark SR solutions.
DocID17595 Rev 2 5/32
AN3233 Main characteristics and circuit description
32
In order to decrease the output capacitors size, aluminium solid capacitors with very low
ESR were preferred to standard electrolytic ones. Therefore, high frequency output voltage
ripple is limited and output LC filter is not required. This choice allows a saving of output
inductor power dissipation which can be significant in the case of high output current
applications like this.
Start-up sequence
The PFC acts as master and the resonant stage can operate only if the PFC output is
delivering the nominal output voltage. Therefore, the PFC starts first and then the
downstream converter turns on. At the beginning, the L6563H is supplied by the integrated
high voltage start-up circuit; as soon as the PFC starts switching, a charging pump
connected to the PFC inductor supplies both PFC and resonant controllers and the HV
internal current source is disabled. Once both stages have been activated, the controllers
are supplied also by the auxiliary winding of the resonant transformer, assuring correct
supply voltage even during standby operation.
As the L6563H integrated HV start-up circuit is turned off, and therefore is not dissipative
during the normal operation, it gives a significant contribution to power consumption
reduction when the power supply operates at light load, in accordance with worldwide
standby standards currently required.
Standby power saving
The board has a burst mode function implemented which allows power saving during light
load operation.
The L6599A's STBY pin (pin 5) senses the optocoupler’s collector voltage (U3), which is
related to the feedback control. This signal is compared to an internal reference (1.24 V). If
the voltage on the pin is lower than the reference, the IC enters an idle state and its
quiescent current is reduced. When the voltage exceeds the reference by 50 mV, the
controller restarts the switching.
The burst mode operation load threshold can be programmed by properly choosing the
resistor connecting the optocoupler to pin RFMIN (R34). Basically, R34 sets the switching
frequency at which the controller enters burst mode.
As the power at which the converter enters burst mode operation heavily influences
converter efficiency at light load, it must be properly set. Anyhow, despite this threshold
being well set, if its tolerance is too wide, the light load efficiency of mass production
converters has a considerable spread.
The main factors affecting the burst mode threshold tolerance are the control circuitry
tolerances and, even more influential, the tolerances of resonant inductance and the
resonant capacitor. Slight changes of resonance frequency can affect the switching
frequency and, consequently, notably change the burst mode threshold.
Typical production spread of these parameters, which fits the requirements of many
applications, are no longer acceptable if very low power consumption in standby must be
guaranteed.
As reducing production tolerance of resonant components causes cost increases, a new
cost-effective solution is required.
The key point of the proposed solution is to directly sense the output load to set the burst
mode threshold. In this way the resonant elements parameters no longer affect this
threshold. The implemented circuit block diagram is shown in Figure 2.
Main characteristics and circuit description AN3233
6/32 DocID17595 Rev 2
Figure 2. Burst mode circuit block diagram
The output current is sensed by a resistor (RCS); the voltage drop across this resistor is
amplified by TSC101, a dedicated high side current sense amplifier; its output is compared
to a set reference by the TSM1014; if the output load is high, the signal fed into the CC- pin
is above the reference voltage, CC_OUT stays down and the optocoupler transistor pulls up
the L6599A’s STBY pin to the RFMIN voltage (2 V), setting continuous switching operation
(no burst mode); if load decreases, the voltage on CC- falls below the set threshold,
CC_OUT goes high opening the connection between RFMIN and STBY and so allowing
burst mode operation by the L6599A.
RCS is dimensioned considering two constraints. The first is the maximum power dissipation
allowed, based on the efficiency goal. The second limitation is imposed by the necessity to
feed a reasonable voltage signal into the TSM1014A inverting input. In fact, signals which
are too small would affect system accuracy.
On this board, the maximum acceptable power dissipation has been set to:
Ploss,MAX = 500 mW. RCS maximum value is calculated as follows:
Equation 1
The burst mode threshold is set at 5 W corresponding to CBM = 417 mA output current at 1
2 V.
Choosing VCC+,min = 50 mV as the minimum reference of the TSM1014A, which allows
a good signal-to-noise ratio, the RCS minimum value is calculated as follows:
Equation 2
The actual value of the mounted resistor is 2 mΩ, corresponding to Ploss = 312 mW power
losses at full load. The actual resistor value at burst mode threshold current provides an
output voltage by TSC101 of 83 mV. The reference voltage of TSM1014 VCC+ must be set at
Comp.
+
-
L6599A TSM1014 TSC101
to load
to FB optocoupler
to power transformer
Comp.
+
-
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-
+
Standby
STBY
RFMIN
CC_OUT
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1.24V
CC- OUT
CC+
1.25V
V_REF
RCS
RH
RFB
RBM
RBM
RL
RHts
Rlim
100
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VM
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MAXloss,
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R
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minCC+,
minCS,
DocID17595 Rev 2 7/32
AN3233 Main characteristics and circuit description
32
this level. The resistor divider setting the TSM1014 threshold RH and RL should be in the
range of kilo-ohms to minimize dissipation. By selecting RL = 22 kΩ, the right RH value is
obtained as follows:
Equation 3
The value of the mounted resistor is 330 kΩ.
RHts sets a small de-bouncing hysteresis and is in the range of mega-ohms. Rlim is in the
range of tens of kilo-ohms and limits the current flowing through the optocoupler’s diode.
Both L6599A and L6563H implement their own burst mode function but, in order to improve
the overall power supply efficiency, at light load the L6599A drives the L6563H via the
PFC_STOP pin and enables the PFC burst mode: as soon as the L6599A stops switching
due to load drops, its PFC_STOP pin pulls down the L6563H’s PFC_OK pin disabling PFC
switching. Thanks to this simple circuit, the PFC is forced into idle state when the resonant
stage is not switching and rapidly wakes up when the downstream converter restarts
switching.
Fast voltage feedforward
The voltage on the L6563H VFF pin (pin 5) is the peak value of the voltage on the MULT pin
(pin 3). The RC network (R15 + R26, C12) connected to VFF completes a peak-holding
circuit. This signal is necessary to derive information of the RMS input voltage to
compensate the loop gain that is mains voltage dependent.
Generally speaking, if the time constant is too small, the voltage generated is affected by a
considerable amount of ripple at twice the mains frequency causing distortion of the current
reference (resulting in higher THD and lower PF). If the time constant is too large, there is a
considerable delay in setting the right amount of feed-forward, resulting in excessive
overshoot or undershoot of the pre-regulator’s output voltage in response to large line
voltage changes.
To overcome this issue, the L6563H implements the fast voltage feedforward function. As
soon as the voltage on the VFF pin decreases by a set threshold (40 mV typically), a mains
dip is assumed and an internal switch rapidly discharges the VFF capacitor via a 10 k
resistor. Thanks to this feature, it is possible to set an RC circuit with a long time constant,
assuring a low THD, keeping a fast response to mains dip.
Brownout protection
Brownout protection prevents the circuit from working with abnormal mains levels. It is easily
achieved using the RUN pin (pin 12) of the L6563H: this pin is connected through a resistor
divider to the VFF pin (pin 5), which provides the information of the mains voltage peak
value. An internal comparator enables the IC operations if the mains level is correct, within
the nominal limits. At startup, if the input voltage is below 90 Vac (typ.), circuit operations are
inhibited.
Output voltage feedback loop
The feedback loop is implemented by means of a typical circuit using the dedicated
operational amplifier of TSM1014A modulating the current in the optocoupler’s diode. The
309kΩ
V
V1.25VR
R
BM
BML
H
Main characteristics and circuit description AN3233
8/32 DocID17595 Rev 2
second comparator embedded in the TSM1014A - usually dedicated to constant current
regulation - is here utilized for burst mode as previously described.
On the primary side, R34 and D17 connect the RFMIN pin (pin 4) to the optocoupler’s
phototransistor closing the feedback loop. R31, which connects the same pin to ground,
sets the minimum switching frequency. The R-C series R44 and C18 sets both soft-start
maximum frequency and duration.
L6599A overload and short-circuit protection
The current into the primary winding is sensed by the loss-less circuit R41, C27, D11, D10,
R39, and C25 and it is fed into the ISEN pin (pin 6). In the case of overcurrent, the voltage
on the pin overpasses an internal threshold (0.8 V) that triggers a protection sequence. The
capacitor (C45) connected to the DELAY pin (pin 2) is charged by an internal 150 µA current
generator and is slowly discharged by the external resistor (R24). 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 pin decays
because of the external resistor. The IC is soft-restarted as the voltage drops below 0.3 V. In
this way, under short-circuit conditions, the converter works intermittently with very low input
average power.
Open loop protection
Both circuit stages, PFC and resonant, are equipped with their own overvoltage protections.
The PFC controller L6563H monitors its output voltage via the resistor divider connected to
a dedicated pin (PFC_OK, pin 7) protecting the circuit in case of loop failures or
disconnection. If a fault condition is detected, the internal circuitry latches the L6563H
operations and, by means of the PWM_LATCH pin (pin 8), it also latches the L6599A via the
DIS pin (pin 8). The converter is kept latched by the L6563H internal HV start-up circuit that
supplies the IC by charging the Vcc capacitor periodically. To resume converter operation,
a mains restart is necessary.
The output voltage is monitored by sensing the Vcc voltage. If Vcc voltage overrides the
D12 breakdown voltage, Q9 pulls down the L6563H INV pin latching the converter.
DocID17595 Rev 2 9/32
AN3233 Main characteristics and circuit description
32
Figure 3. Electrical diagram
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Efficiency measurement AN3233
10/32 DocID17595 Rev 2
2 Efficiency measurement
EPA rev. 2.0 external power supply compliance verification
Table 1 shows the no-load consumption and the overall efficiency, measured at the nominal
mains voltages. At 115 Vac the average efficiency is 90.6 %, while at 230 Vac it is 91.8 %.
Both values are much higher than the 87 % required by EPA rev 2.0 external power supply
(EPS) limits.
The efficiency at nominal load, 230 Vac, is 94 %, which is a very high efficiency for a double
stage converter and confirms the benefit of implemented SR.
Also at no load the board performances are superior: maximum no-load consumption at
nominal mains voltage is 200 mW; this value is significantly lower than the limit imposed by
the ENERGY STAR program which is 500 mW.
Table 1. Overall efficiency
Test
230 V - 50 Hz 115 V - 60 Hz
Vout
[V]
Iout
[A]
Pout
[W]
Pin
[W]
Eff.
[%]
Vout
[V]
Iout
[A]
Pout
[W]
Pin
[W]
Eff.
[%]
No load 12.10 0.00 0.00 0.20 - 12.10 0.00 0.00 0.20 -
25 % load eff. 12.14 3.10 37.63 43.15 87.2 % 12.13 3.10 37.60 43.08 87.3 %
50 % load eff. 12.14 6.19 75.15 81.30 92.4 % 12.12 6.19 75.02 82.34 91.1 %
75 % load eff. 12.08 9.37 113.19 120.81 93.7 % 12.07 9.38 113.22 123.00 92.0 %
100 % load eff. 12.04 12.47 150.14 159.79 94.0 % 12.04 12.50 150.50 163.90 91.8 %
Average eff. - 91.8 % - 90.6 %
DocID17595 Rev 2 11/32
AN3233 Efficiency measurement
32
Light load operation efficiency
Measurement results are reported in Tab le 2 and plotted in Figure 4. As can be seen,
efficiency is better than 50 % even for very light loads such as 500 mW.
Figure 4. Light load efficiency diagram
Table 2. Light load efficiency
Test
230 V - 50 Hz 115 V - 60 Hz
Vout
[V]
Iout
[mA]
Pout
[W]
Pin
[W]
Eff.
[%]
Vout
[V]
Iout
[mA]
Pout
[W]
Pin
[W]
Eff.
[%]
0.25 W 12.12 20.84 0.253 0.581 43.5 % 12.12 20.84 0.253 0.565 44.7 %
0.5 W 12.12 41.34 0.501 0.931 53.8 % 12.12 41.34 0.501 0.912 55.0 %
1.0 W 12.12 82.65 1.002 1.553 64.5 % 12.12 82.65 1.002 1.552 64.5 %
1.5 W 12.12 123.93 1.502 2.203 68.2 % 12.12 123.93 1.502 2.211 67.9 %
2.0 W 12.12 164.93 1.999 2.797 71.5 % 12.12 164.93 1.999 2.828 70.7 %
2.5 W 12.12 206.75 2.506 3.392 73.9 % 12.12 206.75 2.506 3.439 72.9 %
3.0 W 12.11 248.00 3.003 3.979 75.5 % 12.11 248.00 3.003 4.040 74.3 %
3.5 W 12.11 288.25 3.491 4.560 76.6 % 12.11 288.25 3.491 4.644 75.2 %
4.0 W 12.11 330.06 3.997 5.155 77.5 % 12.11 330.06 3.997 5.258 76.0 %
4.5 W 12.11 372.31 4.509 5.748 78.4 % 12.11 372.31 4.509 5.874 76.8 %
5.0 W 12.11 413.34 5.006 6.327 79.1 % 12.11 413.34 5.006 6.474 77.3 %
40%
45%
50%
55%
60%
65%
70%
75%
80%
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
Efficiency [%]
Pout [W]
230V-50Hz
115V-60H z
Harmonic content measurement AN3233
12/32 DocID17595 Rev 2
3 Harmonic content measurement
The board has been tested according to the European standard EN61000-3-2 Class-D and
the Japanese standard JEITA-MITI Class-D, at both the nominal input voltage mains. As
shown in the following images, the circuit is able to reduce the harmonics well below the
limits of both regulations.
Figure 5. Compliance with EN61000-3-2 at 230 Vac – 50 Hz, full load
THD = 14.70 % - PF = 0.978
Figure 6. Compliance with JEITA-MITI at 100 Vac – 50 Hz, full load
THD = 5.20 % - PF = 0.995
On the bottom side of the diagrams the total harmonic distortion (THD) and power factor
(PF) have been measured too. The values in all conditions give a clear idea regarding the
correct functioning of the PFC.
0.1
1
Current [A]
Measured Value
EN610003 2 ClassD Limits
0.0001
0.001
0.01
0.1
1
1 3 5 7 9 111315171921232527293133353739
Harmonic
Harmonic Order [n]
0.1
1
[A]
Measured Value
JEITAMITI Class D Limits
0.0001
0.001
0.01
0.1
1
1 3 5 7 9 111315171921232527293133353739
Harmonic
Current
Harmonic Order [n]
DocID17595 Rev 2 13/32
AN3233 Functional check
32
4 Functional check
Steady-state operation
In Figure 7 some waveforms relevant to the resonant stage during steady-state operation
are given. The selected switching frequency is about 120 kHz, in order to have a good trade
off between transformer losses and dimensions. The converter operates slightly above the
resonance frequency.
Figure 8 shows the key signals of the SRK2000A: each rectifier MOSFET is switched on
and off according to its drain-source voltage which, during conduction time, is the voltage
image of the current flowing through the MOSFET.
Figure 7. Resonant stage waveforms
at 115 V – 60 Hz – full load
Figure 8. SRK2000A key signals
at 115 V – 60 Hz – full load
CH1: HB voltage CH2: CF pin voltage CH1: GD1 pin voltage CH2: DVS1 pin
- CH4: Res. tank current CH3: GD2 pin voltage CH4: DVS2 pin
Functional check AN3233
14/32 DocID17595 Rev 2
Zero voltage switching
Figure 9 and 10 show details of ZVS operation. Both MOSFETs turn on when current is
flowing through their body diodes and drain-source voltage is zero.
Startup and shutdown
Figure 11 and 12 show the start-up and shut-down sequence of the two converter stages:
The PFC starts first and the LLC only starts after the PFC achieves regulation. In the same
way the PFC stops first and the LLC shuts down as its input voltage falls below the allowed
voltage.
Figure 13 and 14 again show startup and shutdown but highlighting the current flowing
through the resonant tank.
Figure 9. High-side MOSFET ZV turn-on
at 115 V – 60 Hz – full load
Figure 10. Low-side MOSFET ZV turn-on
at 115 V – 60 Hz – full load
CH1: HB voltage CH2: HVG pin voltage CH1: HB voltage CH2: HVG pin voltage
CH3: LVG pin voltage - CH3: LVG pin voltage -
Figure 11. Converter startup
at 115 Vac full load
Figure 12. Converter shutdown
at 115 Vac full load
CH1: half-bridge node CH2: PFC drain CH1: half-bridge node CH2: PFC drain
CH3: output voltage CH4: LINE pin CH3: output voltage CH4: LINE pin
DocID17595 Rev 2 15/32
AN3233 Functional check
32
In Figure 13 it can be noted that the resonant current at turn-on has some oscillations due to
the charging of the resonant elements. However, current zero-crossing always lags the HB
commutations and, consequently, MOSFETs are soft switched.
Figure 14 shows the resonance current at shutdown. Due to input voltage dip, the LLC
stage operates below resonance, but current still lags the HB voltage.
Avoiding hard switching also during transitions like startup and shutdown is a must for a
reliable design, because some hard switching commutations could also damage the
converter.
No-load operation
In Figure 15 and 16, some burst mode waveforms are captured. As seen, both L6599A and
L6563H operate in burst mode. In Figure 16, it is possible to see that PFC and LLC bursts
are synchronized.
Figure 13. Startup resonant current Figure 14. Shutdown resonant current
CH1: half-bridge CH3 C6 voltage CH1: half-bridge -
- CH4: res. tank current - CH4: res. tank current
Figure 15. No-load operation Figure 16. No-load operation – detail
CH1: LVG pin CH2: PFC gate CH1: half-bridge CH2: PFC drain
CH3: output voltage CH4: STBY pin CH3: PFC-STOP pin CH4: STBY pin
Functional check AN3233
16/32 DocID17595 Rev 2
In Figure 17 and 18 the transitions from full load to no load and vice versa have been
checked. As seen in the images, both transitions are clean and there isn’t any output
voltage dip.
Overcurrent and short-circuit protection
The L6599A 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 the soft-start capacitor CSS to be discharged.
Under output short-circuit, this operation results in an almost constant peak primary current.
With the L6599A, the board designer can externally program 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, therefore providing the
system with immunity to short duration phenomena. If, instead, the overload condition
continues, a protection procedure is activated that shuts down the L6599A and, in case of
continuous overload/short-circuit, results in continuous intermittent operation with a user
defined duty cycle. This function is realized with the DELAY pin (pin 2), by means of a
capacitor C45 and the parallel resistor R24 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 C45. As the voltage
on C45 is 3.5 V, the L6599A stops switching and the PFC_STOP pin is pulled low. Also the
internal generator is turned off, so that C45 is now slowly discharged by R24. The IC restarts
when the voltage on C45 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 L6599A shuts down and the operation is resumed after an off-on cycle.
Figure 19 shows intermittent operations caused by an output short-circuit: average output
current is limited, preventing the converter from overheating and consequent failure.
Figure 17. Transition full load to no load
at 115 Vac – 60 Hz
Figure 18. Transition no load to full load
at 115 Vac – 60 Hz
CH1: LVG pin CH2: PFC gate CH1: LVG pin CH2: PFC gate
CH3: output voltage CH4: output current CH3: output voltage CH4: output current
DocID17595 Rev 2 17/32
AN3233 Functional check
32
Figure 19. Short-circuit at full load and 115 Vac – 60 Hz
CH1: LVG pin CH2: output voltage
CH3: DELAY pin CH4: output current
Thermal map AN3233
18/32 DocID17595 Rev 2
5 Thermal map
In order to check the design reliability, a thermal mapping by means of an IR camera was
done. In Figure 20 and 21 the thermal measurements of the board, component side, at
nominal input voltage, are shown. Some pointers, visible in the images, have been placed
across key components or components showing high temperature. The ambient
temperature during both measurements was 27 °C.
Figure 20. Thermal map at 115 Vac – 60 Hz - full load
Figure 21. Thermal map at 230 Vac – 50 Hz - full load
Table 3. Thermal maps reference points
Point Reference Description
A D1 Bridge rectifier
B L1 EMI filtering inductor
C L2 PFC inductor
D Q8 ICs supply regulator
E D4 PFC output diode
F R6 Inrush limiting NTC resistor
G Q4 Resonant low side MOSFET
H T1 Resonant power transformer
DocID17595 Rev 2 19/32
AN3233 Thermal map
32
To directly check the efficiency of the SR stage, a thermal map of the SR daughterboard has
also been taken. As seen, the temperature of both rectifier MOSFETs is below 70 °C,
confirming that heatsinking is not required and confirming that the SR solution implemented
allows a significant secondary side board dimension squeezing.
Figure 22. Thermal map SR daughterboard - full load
Table 4. Daughterboard thermal map reference points
Point Reference Description
SP1 Q501 SR MOSFET
SP2 Q502 SR MOSFET
Conducted emission pre-compliance test AN3233
20/32 DocID17595 Rev 2
6 Conducted emission pre-compliance test
Figure 23 and 24 represent the average measurement of the conducted emission at full load
and nominal mains voltages. The limit indicated in red on the diagrams is relevant to
average measurements and is the EN55022 Class-B one, which has more severe limits
compared to Class-A, dedicated to IT technology equipment. As can be seen, in all test
conditions the measurements are significantly below the limits.
Figure 23. CE average measurement at 115 Vac and full load
Figure 24. CE average measurement at 230 Vac and full load
DocID17595 Rev 2 21/32
AN3233 Bill of material
32
7 Bill of material
Table 5. EVL150W-ADP-SR demonstration board: motherboard bill of materials
Des. Part type/
part value Description Supplier Case
C1 470 NF X2 - film cap. - B32922C3474K EPCOS 9.0 x 18.0 p. 15 mm
C2 2.2 NF Y1 safety cap. DE1E3KX222M MURATA P. 10 mm
C3 2.2 NF Y1 safety cap. DE1E3KX222M MURATA P. 10 mm
C4 470 NF X2 - film cap. - B32922C3474K EPCOS 9.0 x 18.0 p. 15 mm
C5 470 NF 520 V - film cap. - B32673Z5474K EPCOS 7.0 x 26.5 p. 22.5 mm
C6 4.7 NF 50 V cercap - general purpose AVX 0805
C7 100 NF 100 V cercap - general purpose AVX PTH
C8 10 F - 50 V Aluminium elcap - YXF series - 105 °C RUBYCON Dia. 5.0 x 11 p. 2 mm
C9 100 F - 450 V Aluminium elcap - UPZ2W101MHD NICHICON Dia. 18 x 32 mm
C10 1 NF 50 V cercap - general purpose AVX 0805
C11 2.2 NF 50 V cercap - general purpose AVX 0805
C12 1 F 25 V cercap - general purpose AVX 0805
C13 680 NF 25 V cercap - general purpose AVX 1206
C14 68 NF 50 V cercap - general purpose AVX 0805
C15 47 F - 50 V Aluminium elcap - YXF series - 105 °C RUBYCON Dia. 6.3 x 11
p. 2.5 mm
C16 2.2 NF 50 V cercap - general purpose AVX 1206
C17 330 PF 50 V - 5 % - C0G - cercap AVX 0805
C18 4.7 F 25 V cercap - general purpose MURATA 1206
C19 100 NF 50 V cercap - general purpose AVX 1206
C20 2.2 NF Y1 safety cap. DE1E3KX222M MURATA P. 10 mm
C21 2.2 NF Y1 safety cap. DE1E3KX222M MURATA P. 10 mm
C22 220 PF 50 V cercap - general purpose AVX 0805
C23 10 NF 50 V cercap - general purpose AVX 0805
C24 220 F - 50 V Aluminium elcap - YXF series - 105 °C RUBYCON Dia.10 x 16 p. 5 mm
C25 2.2 F 50 V cercap - general purpose AVX 0805
C26 10 F - 50 V Aluminium elcap - YXF series - 105 °C RUBYCON Dia. 5.0 x 11 p. 2 mm
C27 220 pF - 630 V 630 V cercap - GRM31A7U2J220JW31 MURATA 1206
C28 22 NF 1 KV - film cap - B32652A223K EPCOS 5.0 x 18.0 p15 mm
C29 470 F - 16 V 16 V aluminium solid capacitor SANYO Dia. 10 X 13 p5 mm
C30 470 F - 16 V 16 V aluminium solid capacitor SANYO Dia. 10 x 13 p5 mm
C32 1 F 50 V cercap - general purpose AVX 0805
Bill of material AN3233
22/32 DocID17595 Rev 2
C33 1 NF 50 V cercap - general purpose AVX 0805
C34 100 NF 50 V cercap - general purpose AVX 0805
C36 1 F - 350 V 50 V cercap - general purpose AVX 1206
C37 470 F - 16 V 16 V aluminium solid capacitor SANYO Dia. 10 x 13 p. 5 mm
C38 100 NF 50 V cercap - general purpose AVX 0805
C39 100 NF 50 V cercap - general purpose AVX 0805
C40 100 NF 50 V cercap - general purpose AVX 1206
C41 22 NF 50 V cercap - general purpose AVX 0805
C42 100 NF 50 V cercap - general purpose AVX 0805
C43 4.7 NF 50 V cercap - general purpose AVX 0805
C44 3.3 NF 50 V cercap - general purpose AVX 0805
C45 220 NF 25 V cercap - general purpose AVX 0805
C47 1 NF 50 V cercap - general purpose AVX 0805
C48 1 NF 50 V cercap - general purpose AVX 0805
C49 470 F 16 V aluminium solid capacitor SANYO Dia. 10 x 13 p. 5 mm
C50 470 F 16 V aluminium solid capacitor SANYO Dia. 10 x 13 p. 5 mm
C51 100 NF 50 V cercap - general purpose AVX 0805
C52 1 NF 25 V cercap - general purpose AVX 0805
D1 GBU8J Single phase bridge rectifier VISHAY STYLE GBU
D2 LL4148 High speed signal diode VISHAY Minimelf SOD-80
D3 1N4005 General purpose rectifier VISHAY DO-41 DO - 41
D4 STTH5L06 Ultrafast high voltage rectifier STMicroelectronics DO-201
D5 LL4148 High speed signal diode VISHAY Minimelf SOD-80
D6 LL4148 High speed signal diode VISHAY Minimelf SOD-80
D7 STPS140Z Power Schottky rectifier STMicroelectronics SOD-123
D9 STPS1L60A Power Schottky diode STMicroelectronics SMA
D10 LL4148 High speed signal diode VISHAY Minimelf SOD-80
D11 LL4148 High speed signal diode VISHAY Minimelf SOD-80
D12 BZV55-C43 Zener diode VISHAY Minimelf SOD-80
D14 LL4148 High speed signal diode VISHAY Minimelf SOD-80
D16 LL4148 High speed signal diode VISHAY Minimelf SOD-80
D17 LL4148 High speed signal diode VISHAY Minimelf SOD-80
D18 LL4148 High speed signal diode VISHAY Minimelf SOD-80
D19 LL4148 High speed signal diode VISHAY Minimelf SOD-80
Table 5. EVL150W-ADP-SR demonstration board: motherboard bill of materials (continued)
Des. Part type/
part value Description Supplier Case
DocID17595 Rev 2 23/32
AN3233 Bill of material
32
D20 BZV55-B15 Zener diode VISHAY Minimelf SOD-80
D21 LL4148 High speed signal diode VISHAY Minimelf SOD-80
F1 FUSE T4A Fuse 4 A - time lag - 3921400 LITTLEFUSE 8.5 x 4 p. 5.08 mm
HS1 HEATSINK Heatsink for D1, Q1, Q3, Q4 - DWG
J1 MKDS 1,5/
3-5,08 PCB term. block, screw conn., pitch 5 mm - 3 W PHOENIX
CONTACT DWG
J2 FASTON Faston - connector - DWG
J3 FASTON Faston - connector - DWG
L1 2019.0002 Common mode choke - EMI filter MAGNETICA DWG
L2 1975.0004 PFC inductor - 0.31 mH - PQ26/25 MAGNETICA DWG
Q1 STF19NM50N N-channel power MOSFET STMicroelectronics TO-220FP
Q2 BC857 PNP small signal BJT VISHAY SOT-23
Q3 STF8NM50N N-channel power MOSFET STMicroelectronics TO-220FP
Q4 STF8NM50N N-channel power MOSFET STMicroelectronics TO-220FP
Q8 BC847C NPN small signal BJT VISHAY SOT-23
Q9 BC847C NPN small signal BJT VISHAY SOT-23
R1 3.3 MSMD film res. - 1/4 W - 5 % - 250 ppm/°C VISHAY 1206
R2 3.3 MSMD film res. - 1/4 W - 5 % - 250 ppm/°C VISHAY 1206
R3 1 MSMD film res. - 1/4 W - 1 % - 100 ppm/°C VISHAY 1206
R5 10 SMD film res. - 1/4 W - 5 % - 250 ppm/°C VISHAY 1206
R6 NTC 2R5-S237 NTC resistor P/N B57237S0259M000 EPCOS DWG
R7 1 MSMD film res. - 1/4 W - 1 % - 100 ppm/°C VISHAY 1206
R8 1 MSMD film res. - 1/4 W - 1 % - 100 ppm/°C VISHAY 1206
R9 62 KSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R10 27 KSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R11 2.2 MSMD film res. - 1/4 W - 1 % - 100 ppm/°C VISHAY 1206
R12 2.2 MSMD film res. - 1/4 W - 1 % - 100 ppm/°C VISHAY 1206
R13 8.2 KSMD film res. - 1/4 W - 1 % - 100 ppm/°C VISHAY 1206
R14 51 KSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R15 56 KSMD film res. - 1/4 W - 1 % - 100 ppm/°C VISHAY 1206
R16 4.7 KSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R17 2.2 MSMD film res. - 1/4 W - 1 % - 100 ppm/°C VISHAY 1206
R18 82 KSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R19 56 KSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
Table 5. EVL150W-ADP-SR demonstration board: motherboard bill of materials (continued)
Des. Part type/
part value Description Supplier Case
Bill of material AN3233
24/32 DocID17595 Rev 2
R20 33 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R21 22 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R22 0.27 SFR25 axial stand. film res. - 0.4 W - 5 % - 250
ppm/°C VISHAY PTH
R23 0.47 SFR25 axial stand. film res. - 0.4 W - 5 % - 250
ppm/°C VISHAY PTH
R24 1 MSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R25 56 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R26 1 MSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R27 470 RSMD film res. - 1/4 W - 5 % - 250 ppm/°C VISHAY 1206
R28 33 KSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R29 1 KSMD film res. - 1/4 W - 5 % - 250 ppm/°C VISHAY 1206
R30 10 SMD film res .- 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R31 12 KSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R32 47 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R34 27 KSMD film res .- 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R35 180 KSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R36 1.8 MSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R37 220 KSMD film res. - 1/4 W - 5 % - 250 ppm/°C VISHAY 1206
R38 56 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R39 160 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R40 33 SMD film res. - 1/4 W - 5 % - 250 ppm/°C VISHAY 1206
R41 100 SFR25 axial stand. film res. - 0.4 W - 5 % -
250 ppm/°C VISHAY PTH
R42 1 KSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R43 51 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R44 6.2 KSMD film res. - 1/4 W - 5 % - 250 ppm/°C VISHAY 1206
R45 3.3 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R46 100 KSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R48 47 KSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R49 91 KSMD film res. - 1/4 W - 1 % - 100 ppm/°C VISHAY 1206
R50 12 KSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R51 82 K SMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R52 1.5 KSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R53 2.2 KSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
Table 5. EVL150W-ADP-SR demonstration board: motherboard bill of materials (continued)
Des. Part type/
part value Description Supplier Case
DocID17595 Rev 2 25/32
AN3233 Bill of material
32
R54 0 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R55 2.7 KSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R57 0.02 SMD shunt resistor - RL3264-9V-R002-FNH-11 CYNTEC 2512
R58 100 KSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R59 100 KSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R60 10 K SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R63 0 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R64 10 MSMD film res.- 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R68 39 KSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R69 4.7 KSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R70 22 kSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R71 1 KSMD film res. - 1/4 W - 5 % - 250 ppm/°C VISHAY 1206
R72 330 KSMD film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R73 22 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R75 0 SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R76 33 K SMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R77 1 KSMD film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
T1 1860.0034 Resonant power transformer MAGNETICA ETD34
U1 L6563H High voltage start-up TM PFC controller STMicroelectronics SO-16
U2 L6599AD Improved HV resonant controller STMicroelectronics SO-16
U3 SFH617A-2 Optocoupler INFINEON DIP-4 - 10.16 mm
U4 SFH617A-2 Optocoupler INFINEON DIP-4 - 10.16 mm
U5 TSM1014AIST Low consumption CV/CC controller STMicroelectronics MINI SO-8
U6 TSC101C High side current sense amplifier STMicroelectronics SOT23-5
Table 5. EVL150W-ADP-SR demonstration board: motherboard bill of materials (continued)
Des. Part type/
part value Description Supplier Case
Bill of material AN3233
26/32 DocID17595 Rev 2
Table 6. EVL150W-ADP-SR evaluation board: daughterboard bill of material
Des. Part type/
part value Description Supplier Case
C501 4.7 nF 50 V cercap - general purpose VISHAY 0805
C502 100 nF 50 V cercap - general purpose VISHAY 0805
C503 1 F 50 V cercap - general purpose VISHAY 0805
D501 BAS316 Fast switching signal diode STMicroelectronics SOD-123
D502 BAS316 Fast switching signal diode STMicroelectronics SOD-123
JP501 HEADER 13 13-pin connector - -
Q501 STL140N4LLF5 N-channel power MOSFET STMicroelectronics POWER FLAT
Q502 STL140N4LLF5 N-channel power MOSFET STMicroelectronics POWER FLAT
R501 10 SMD standard film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R502 10 SMD standard film res .- 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R503 10 SMD standard film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R504 150 kSMD standard film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R505 33 kSMD standard film res. - 1/8 W - 1 % - 100 ppm/°C VISHAY 0805
R506 330 SMD standard film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
R507 330 SMD standard film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
RX1 0 SMD standard film res. - 1/8 W - 5 % - 250 ppm/°C VISHAY 0805
U501 SRK2000A SR smart driver for LLC resonant converter STMicroelectronics SO8
DocID17595 Rev 2 27/32
AN3233 PFC coil specification
32
8 PFC coil specification
General description and characteristics
Application type: consumer, home appliance
Transformer type: open
Coil former: vertical type, 6 + 6 pins
Max. temp. rise: 45 ºC
Max. operating ambient temperature: 60 ºC
Mains insulation: n.a.
Unit finishing: varnished
Electrical characteristics
Converter topology: boost, transition mode
Core type: PQ26/25-PC44 or equivalent
Min. operating frequency: 40 kHz
Typical operating frequency: 120 kHz
Primary inductance: 310 µH ± 10% at 1 kHz-0.25 V(a)
Peak current: 5.6 Apk
Electrical diagram and winding characteristics
a. Measured between pins #5 and #9.
Figure 25. PFC coil electrical diagram
Table 7. PFC coil winding data
Pins Windings RMS current Number of turns Wire type
11 - 3 AUX 0.05 ARMS 5 0.28 mm – G2
5 - 9 PRIMARY 2.3 ARMS 50 50 x 0.1 mm – G1
11
3
5
9
PFC coil specification AN3233
28/32 DocID17595 Rev 2
Mechanical aspects and pin numbering
Maximum height from PCB: 30 mm
Coil former type: vertical, 6 + 6 pins (pins 1, 2, 4, 6, 7, 10, 12 are removed)
Pin distance: 3.81 mm
Row distance: 25.4 mm
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.
Manufacturer
Magnetica - Italy
Inductor P/N: 1975.0004
Figure 26. PFC coil mechanical aspect
DIMENSIONS IN MILLIMETERS, DRAWING NOT IN SCALE
3.81
11
3
3
5
9
8
28 MAX
30 MAX
22.86
BOTTOM VIEW (PIN SIDE)
11.43
∅ 0.9 (X5)
RECOMMENDED PCB HOLE ∅1.3
3
5
9
11.43
30 MAX
11
25.40
3.81
3.81
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AN3233 Transformer specifications
32
9 Transformer specifications
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 ºC
Max. operating ambient temperature: 60 ºC
Mains insulation: acc. to EN60065.
Electrical characteristics
Converter topology: half bridge, resonant
Core type: ETD34-PC44 or equivalent
Min. operating frequency: 60 kHz
Typical operating frequency: 100 kHz
Primary inductance: 800 µH ± 10% at 1 kHz-0.25 V(b)
Leakage inductance: 100 µH ± 10% at 100 kHz-0.25 V(c).
Electrical diagram and winding characteristics
b. Measured between pins 2 - 4.
c. Measured between pins 2 - 4 with only half secondary winding shorted at time.
Figure 27. Transformer electrical diagram
2
4
6
7
9
13
10
11
12
8
14
Transformer specifications AN3233
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Mechanical aspect and pin numbering
Maximum height from PCB: 30 mm
Coil former type: horizontal, 7 + 7 pins (pins #3 and #5 are removed)
Pin distance: 5.08 mm
Row distance: 25.4 mm
Manufacturer
Magnetica - Italy
Transformer P/N: 1860.0034
Table 8. Transformer winding data
Pins Winding RMS current Number of turns Wire type
2 - 4 PRIMARY 1.2 ARMS 34 30 x 0.1 mm – G1
8 - 11 SEC-1A45 ARMS 290 x 0.1 mm – G1
9 -10 SEC-1B45 ARMS 290 x 0.1 mm – G1
10 - 13 SEC-2A(1)
1. Secondary windings A and B are in parallel.
5 ARMS 290 x 0.1 mm – G1
12 - 14 SEC-2B45 ARMS 290 x 0.1 mm – G1
6 - 7 AUX(2)
2. Aux winding is wound on top of primary winding.
0.05 ARMS 3 0.28 mm– G2
Figure 28. Transformer overall drawing
QUOTES IN MILLIMETERS
,
DRAWING NOT IN SCALE
3
MIN
30
MAX
39
MAX
25.4
39
MAX
LABEL
5.08
1 2 4 6 7
PIN SIDE VIEW
14 13 12 11 10 9 8
Ø1.1 (x12) / PCB hole Ø1.6
MISSING PIN
3
AND
5
AS
PCB
REFERENCE
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AN3233 Revision history
32
10 Revision history
Table 9. Document revision history
Date Revision Changes
13-Jan-2011 1 Initial release
20-Jun-2017 2
Replaced “SRK2000” by “SRK2000A” in the whole document.
Replaced Figure 3 on page 9 by new figure.
Minor modifications throughout document.
AN3233
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