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(R) 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 June 2017 DocID17595 Rev 2 1/32 www.st.com 32 Contents AN3233 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 2/32 DocID17595 Rev 2 AN3233 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. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. EVL150W-ADP-SR: 150 W SMPS demonstration board . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Burst mode circuit block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Light load efficiency diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Compliance with EN61000-3-2 at 230 Vac - 50 Hz, full load . . . . . . . . . . . . . . . . . . . . . . . 13 Compliance with JEITA-MITI at 100 Vac - 50 Hz, full load . . . . . . . . . . . . . . . . . . . . . . . . 13 Resonant stage waveforms at 115 V - 60 Hz - full load . . . . . . . . . . . . . . . . . . . . . . . . . . 14 SRK2000A key signals at 115 V - 60 Hz - full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 High-side MOSFET ZV turn-on at 115 V - 60 Hz - full load. . . . . . . . . . . . . . . . . . . . . . . 15 Low-side MOSFET ZV turn-on at 115 V - 60 Hz - full load . . . . . . . . . . . . . . . . . . . . . . . . 15 Converter startup at 115 Vac full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Converter shutdown at 115 Vac full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Startup resonant current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Shutdown resonant current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 No-load operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 No-load operation - detail. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Transition full load to no load at 115 Vac - 60 Hz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Transition no load to full load at 115 Vac - 60 Hz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Short-circuit at full load and 115 Vac - 60 Hz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Thermal map at 115 Vac - 60 Hz - full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Thermal map at 230 Vac - 50 Hz - full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Thermal map SR daughterboard - full load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 CE average measurement at 115 Vac and full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 CE average measurement at 230 Vac and full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 PFC coil electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 PFC coil mechanical aspect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Transformer electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Transformer overall drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 DocID17595 Rev 2 3/32 32 Main characteristics and circuit description 1 AN3233 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 m, 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. 4/32 DocID17595 Rev 2 AN3233 Main characteristics and circuit description 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. DocID17595 Rev 2 5/32 32 Main characteristics and circuit description AN3233 Figure 2. Burst mode circuit block diagram to power transformer RCS to load to FB optocoupler L6599A RFMIN 2V TSC101 TSM1014 Rlim RFB CC- OUT V_REF Standby Comp. + 1.24V STBY CC_OUT Comp. + RH 1.25V + E/A. 100 VP VM CC+ RL RBM RBM RHts 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 R CS,MAX Ploss,MAX 2 Iout, MAX 3.2m 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 R CS,min VCC+,min 100 CBM 1.2m The actual value of the mounted resistor is 2 m, 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 6/32 DocID17595 Rev 2 AN3233 Main characteristics and circuit description 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 k, the right RH value is obtained as follows: Equation 3 RH RL 1.25V VBM 309k VBM The value of the mounted resistor is 330 k. 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 DocID17595 Rev 2 7/32 32 Main characteristics and circuit description AN3233 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 A 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. 8/32 DocID17595 Rev 2 #$$ 2 3 / $ % #;7$ 3 $ V' 3 3 7BD 3 3 3 3 $ /' $ /' $ /' $ /' $ /'9 ' '64&5" DocID17595 Rev 2 3 3 3 $ 1' $ /: $ /': 3 $ 3 )74 /$ 18.4501 36/ ;$% (/% (% 7$$ 6 -) 3 $ /'9 18.-"5$) 1'$0, 5#0 7'' $4 .6-5 $0.1 */7 - 3 / % 3 $ /' $ _ % (#6+ _ + .,%4 /' $ $ /' $ /' 3 % / 3 3 $ 1' 3 3 8 3 3 3 $ Q' 2 #$ $ /' $ /' % 4514; /'7 3 @ $ 3 3 %&-": $44 6 -"% %*4 -*/& *4&/ 45#: 3'.*/ $' $ 1'$4501 (/% -7( 7$$ /$ 065 )7( 7#005 3 3 3 3 % / % #;7# $ /' % / % / 2 #$$ % / % / $ /' 3 - $ /' $ /' $ % / % 455)- )4 )&"54*/, 3 2 45'/./ 3 /5$34 3 3 3 3 3 3 3 3 3 % / 3 $ 3 % / 3 3 3 % / $ $ % 4514-" 3 3 2 45'/./ 2 45'/./ % / $ $ /': $ /': $ /' $ /' 6 4')" 6 4')" 5 &7-43,- +1 $ /' 3 $ 3 3 3 39 3 3 $ O' 3 3 3 $ 3 3 $ /' 3 (% 3 $ /' (% 1(/% 3 $ %74 %74 &/ 7$$ 6 43," 4(/% $ O' $ $7 $$ $$ 7@3&' % #"4 $7@065 (/% $$@065 7$$ % #"4 3 3 $ 6 54."*45 $ 3 $ 3 6 7N 7DD 3 3 54$ 7Q (/% 0VU $ /' $ 2 45-/--' 2 45-/--' + + ". '"450/ $ /' '"450/ 7" /' $ AN3233 Main characteristics and circuit description Figure 3. Electrical diagram 9/32 32 Efficiency measurement 2 AN3233 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 230 V - 50 Hz Test Vout Iout Pout Pin Eff. Vout Iout Pout Pin Eff. [V] [A] [W] [W] [%] [V] [A] [W] [W] [%] 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 % 91.8 % - 90.6 % No load Average eff. 10/32 115 V - 60 Hz - DocID17595 Rev 2 AN3233 Efficiency measurement Light load operation efficiency Measurement results are reported in Table 2 and plotted in Figure 4. As can be seen, efficiency is better than 50 % even for very light loads such as 500 mW. Table 2. Light load efficiency 230 V - 50 Hz Test 115 V - 60 Hz Vout Iout Pout Pin Eff. Vout Iout Pout Pin Eff. [V] [mA] [W] [W] [%] [V] [mA] [W] [W] [%] 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 % Figure 4. Light load efficiency diagram 80% 75% Efficiency [%] 70% 65% 60% 230V-50Hz 55% 115V-60Hz 50% 45% 40% 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Pout [W] DocID17595 Rev 2 11/32 32 Harmonic content measurement 3 AN3233 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 Measured Value Harmonic Current [A] EN610003 2 ClassD Limits 1 0.1 0.01 0.001 0.0001 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Harmonic Order [n] THD = 14.70 % - PF = 0.978 Figure 6. Compliance with JEITA-MITI at 100 Vac - 50 Hz, full load Measured Value JEITAMITI Class D Limits Harmonic Current [A] 1 0.1 0.01 0.001 0.0001 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Harmonic Order [n] 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. 12/32 DocID17595 Rev 2 AN3233 4 Functional check 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 CH1: HB voltage - CH2: CF pin voltage CH4: Res. tank current Figure 8. SRK2000A key signals at 115 V - 60 Hz - full load CH1: GD1 pin voltage CH3: GD2 pin voltage DocID17595 Rev 2 CH2: DVS1 pin CH4: DVS2 pin 13/32 32 Functional check AN3233 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. Figure 9. High-side MOSFET ZV turn-on at 115 V - 60 Hz - full load CH1: HB voltage CH3: LVG pin voltage CH2: HVG pin voltage - Figure 10. Low-side MOSFET ZV turn-on at 115 V - 60 Hz - full load CH1: HB voltage CH3: LVG pin voltage CH2: HVG pin voltage - 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 11. Converter startup at 115 Vac full load CH1: half-bridge node CH3: output voltage Figure 12. Converter shutdown at 115 Vac full load CH2: PFC drain CH4: LINE pin CH1: half-bridge node CH3: output voltage CH2: PFC drain CH4: LINE pin Figure 13 and 14 again show startup and shutdown but highlighting the current flowing through the resonant tank. 14/32 DocID17595 Rev 2 AN3233 Functional check 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. Figure 13. Startup resonant current CH1: half-bridge - CH3 C6 voltage CH4: res. tank current Figure 14. Shutdown resonant current CH1: half-bridge - CH4: res. tank current 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 15. No-load operation CH1: LVG pin CH3: output voltage Figure 16. No-load operation - detail CH2: PFC gate CH4: STBY pin CH1: half-bridge CH3: PFC-STOP pin DocID17595 Rev 2 CH2: PFC drain CH4: STBY pin 15/32 32 Functional check AN3233 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. 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 CH3: output voltage CH1: LVG pin CH3: output voltage CH2: PFC gate CH4: output current CH2: PFC gate CH4: output current 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 shortcircuits 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 A 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. 16/32 DocID17595 Rev 2 AN3233 Functional check Figure 19. Short-circuit at full load and 115 Vac - 60 Hz CH1: LVG pin CH3: DELAY pin CH2: output voltage CH4: output current DocID17595 Rev 2 17/32 32 Thermal map 5 AN3233 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 18/32 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 AN3233 Thermal map 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 DocID17595 Rev 2 19/32 32 Conducted emission pre-compliance test 6 AN3233 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 20/32 DocID17595 Rev 2 AN3233 7 Bill of material 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 630 V cercap - GRM31A7U2J220JW31 MURATA 1206 C27 220 pF - 630 V 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 DocID17595 Rev 2 21/32 32 Bill of material AN3233 Table 5. EVL150W-ADP-SR demonstration board: motherboard bill of materials (continued) Des. Part type/ part value Description Supplier Case 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 22/32 DocID17595 Rev 2 AN3233 Bill of material Table 5. EVL150W-ADP-SR demonstration board: motherboard bill of materials (continued) Des. Part type/ part value Description Supplier Case 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 M SMD film res. - 1/4 W - 5 % - 250 ppm/C VISHAY 1206 R2 3.3 M SMD film res. - 1/4 W - 5 % - 250 ppm/C VISHAY 1206 R3 1 M SMD 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 M SMD film res. - 1/4 W - 1 % - 100 ppm/C VISHAY 1206 R8 1 M SMD film res. - 1/4 W - 1 % - 100 ppm/C VISHAY 1206 R9 62 K SMD film res. - 1/8 W - 1 % - 100 ppm/C VISHAY 0805 R10 27 K SMD film res. - 1/8 W - 1 % - 100 ppm/C VISHAY 0805 R11 2.2 M SMD film res. - 1/4 W - 1 % - 100 ppm/C VISHAY 1206 R12 2.2 M SMD film res. - 1/4 W - 1 % - 100 ppm/C VISHAY 1206 R13 8.2 K SMD film res. - 1/4 W - 1 % - 100 ppm/C VISHAY 1206 R14 51 K SMD film res. - 1/8 W - 5 % - 250 ppm/C VISHAY 0805 R15 56 K SMD film res. - 1/4 W - 1 % - 100 ppm/C VISHAY 1206 R16 4.7 K SMD film res. - 1/8 W - 5 % - 250 ppm/C VISHAY 0805 R17 2.2 M SMD film res. - 1/4 W - 1 % - 100 ppm/C VISHAY 1206 R18 82 K SMD film res. - 1/8 W - 5 % - 250 ppm/C VISHAY 0805 R19 56 K SMD film res. - 1/8 W - 5 % - 250 ppm/C VISHAY 0805 DocID17595 Rev 2 23/32 32 Bill of material AN3233 Table 5. EVL150W-ADP-SR demonstration board: motherboard bill of materials (continued) Des. Part type/ part value Description Supplier Case 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 M SMD 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 M SMD film res. - 1/8 W - 1 % - 100 ppm/C VISHAY 0805 R27 470 R SMD film res. - 1/4 W - 5 % - 250 ppm/C VISHAY 1206 R28 33 K SMD film res. - 1/8 W - 1 % - 100 ppm/C VISHAY 0805 R29 1 K SMD 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 K SMD 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 K SMD film res .- 1/8 W - 5 % - 250 ppm/C VISHAY 0805 R35 180 K SMD film res. - 1/8 W - 1 % - 100 ppm/C VISHAY 0805 R36 1.8 M SMD film res. - 1/8 W - 5 % - 250 ppm/C VISHAY 0805 R37 220 K SMD 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 K SMD 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 K SMD 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 K SMD film res. - 1/8 W - 5 % - 250 ppm/C VISHAY 0805 R48 47 K SMD film res. - 1/8 W - 5 % - 250 ppm/C VISHAY 0805 R49 91 K SMD film res. - 1/4 W - 1 % - 100 ppm/C VISHAY 1206 R50 12 K SMD 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 K SMD film res. - 1/8 W - 1 % - 100 ppm/C VISHAY 0805 R53 2.2 K SMD film res. - 1/8 W - 1 % - 100 ppm/C VISHAY 0805 24/32 DocID17595 Rev 2 AN3233 Bill of material Table 5. EVL150W-ADP-SR demonstration board: motherboard bill of materials (continued) Des. Part type/ part value Description Supplier Case R54 0 SMD film res. - 1/8 W - 5 % - 250 ppm/C VISHAY 0805 R55 2.7 K SMD 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 K SMD film res. - 1/8 W - 5 % - 250 ppm/C VISHAY 0805 R59 100 K SMD 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 M SMD film res.- 1/8 W - 5 % - 250 ppm/C VISHAY 0805 R68 39 K SMD film res. - 1/8 W - 1 % - 100 ppm/C VISHAY 0805 R69 4.7 K SMD film res. - 1/8 W - 5 % - 250 ppm/C VISHAY 0805 R70 22 k SMD film res. - 1/8 W - 1 % - 100 ppm/C VISHAY 0805 R71 1 K SMD film res. - 1/4 W - 5 % - 250 ppm/C VISHAY 1206 R72 330 K SMD 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 K SMD 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 DocID17595 Rev 2 25/32 32 Bill of material AN3233 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 k SMD standard film res. - 1/8 W - 1 % - 100 ppm/C VISHAY 0805 R505 33 k SMD 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 26/32 DocID17595 Rev 2 AN3233 8 PFC coil specification 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 C Max. operating ambient temperature: 60 C 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 H 10% at 1 kHz-0.25 V(a) Peak current: 5.6 Apk Electrical diagram and winding characteristics Figure 25. PFC coil electrical diagram 5 11 9 3 Table 7. PFC coil winding data a. 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 Measured between pins #5 and #9. DocID17595 Rev 2 27/32 32 PFC coil specification AN3233 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. Figure 26. PFC coil mechanical aspect 28 MAX 30 MAX 30 MAX 11 3 3 9 5 25.40 11 3 11.43 3.81 3.81 11.43 9 5 8 BOTTOM VIEW (PIN SIDE) 22.86 3.81 0.9 (X5) RECOMMENDED PCB HOLE 1.3 DIMENSIONS IN MILLIMETERS, DRAWING NOT IN SCALE Manufacturer 28/32 Magnetica - Italy Inductor P/N: 1975.0004 DocID17595 Rev 2 AN3233 9 Transformer specifications 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 C Max. operating ambient temperature: 60 C 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 H 10% at 1 kHz-0.25 V(b) Leakage inductance: 100 H 10% at 100 kHz-0.25 V(c). Electrical diagram and winding characteristics Figure 27. Transformer electrical diagram 2 8 9 10 11 12 4 6 7 13 14 b. Measured between pins 2 - 4. c. Measured between pins 2 - 4 with only half secondary winding shorted at time. DocID17595 Rev 2 29/32 32 Transformer specifications AN3233 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 4 5 ARMS 2 90 x 0.1 mm - G1 4 5 ARMS 2 90 x 0.1 mm - G1 5 ARMS 2 90 x 0.1 mm - G1 5 ARMS 2 90 x 0.1 mm - G1 0.05 ARMS 3 0.28 mm- G2 SEC-1A 9 -10 SEC-1B 10 - 13 SEC-2A(1) 12 - 14 6-7 SEC-2B 4 (2) AUX 1. Secondary windings A and B are in parallel. 2. Aux winding is wound on top of primary winding. 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 Figure 28. Transformer overall drawing 39 MAX 30 MAX 25.4 3 MIN 39 MAX LABEL 5.08 O1.1 (x12) / PCB hole O1.6 MISSING PIN 3 AND 5 AS PCB REFERENCE PIN SIDE VIEW 1 2 6 7 14 13 12 11 10 9 8 QUOTES IN MILLIMETERS, DRAWING NOT IN SCALE Manufacturer 30/32 Magnetica - Italy Transformer P/N: 1860.0034 DocID17595 Rev 2 4 AN3233 10 Revision history 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. DocID17595 Rev 2 31/32 32 AN3233 IMPORTANT NOTICE - PLEASE READ CAREFULLY STMicroelectronics NV and its subsidiaries ("ST") reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST's terms and conditions of sale in place at the time of order acknowledgement. Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or the design of Purchasers' products. No license, express or implied, to any intellectual property right is granted by ST herein. Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product. ST and the ST logo are trademarks of ST. All other product or service names are the property of their respective owners. Information in this document supersedes and replaces information previously supplied in any prior versions of this document. (c) 2017 STMicroelectronics - All rights reserved 32/32 DocID17595 Rev 2