Part Number Hot Search : 
5X824J8R 03DH35 M5002LFS D1750 TL431 10201 03DH35 8XL51FA
Product Description
Full Text Search
 

To Download AN3172 Datasheet File

  If you can't view the Datasheet, Please click here to try to view without PDF Reader .  
 
 


  Datasheet File OCR Text:
  december 2010 doc id 17230 rev 1 1/31 AN3172 application note 19 v - 90 w adapter with pfc for laptop computers using the l6563h and l6599a introduction this application note describes the performance of a 90 w, wide-range mains, power-factor- corrected, ac-dc adapter demonstration board. its electrical specification is tailored on a typical hi-end portable computer power adapter. the architecture is based on a two-stage approach; a front-end pfc pre-regulator based on the l6563h tm pfc controller and a downstream llc resonant half-bridge converter using the new l6599a resonant controller. thanks to the chipset used, the main aspects of this design are very high efficiency, compliance with energy star ? eligibility criteria (epa rev. 2.0 eps), and very low input consumption at no-load (<0.3 w). figure 1. evl6599a-90wadp: 90 w adapter demonstration board www.st.com
contents AN3172 2/31 doc id 17230 rev 1 contents 1 main characteristics and cir cuit description . . . . . . . . . . . . . . . . . . . . . 5 1.1 startup sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.2 brownout protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3 fast voltage feed forward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.4 resonant power stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.5 output voltage feedback loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.6 l6599a overload and short-circuit protection . . . . . . . . . . . . . . . . . . . . . . . 8 1.7 pfc overvoltage and open-loop protection . . . . . . . . . . . . . . . . . . . . . . . . 8 1.8 standby power saving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2 efficiency measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.1 light-load operation efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3 harmonic content measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4 functional check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.1 standby and no-load operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.2 overcurrent and short-circuit protection . . . . . . . . . . . . . . . . . . . . . . . . . . 16 5 thermal map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6 conducted emission pre-compli ance test . . . . . . . . . . . . . . . . . . . . . . 20 7 bom list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 8 pfc coil specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 8.1 mechanical aspect and pin numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 9 transformer specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 9.1 mechanical aspect and pin numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 10 revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
AN3172 list of figures doc id 17230 rev 1 3/31 list of figures figure 1. evl6599a-90wadp: 90 w adapter demonstration board . . . . . . . . . . . . . . . . . . . . . . . . . . 1 figure 2. electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 figure 3. efficiency vs. output power diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 figure 4. light-load efficiency diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 figure 5. compliance to en61000-3-2 at 230 vac - 50 hz, full load . . . . . . . . . . . . . . . . . . . . . . . . . 13 figure 6. compliance to 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. resonant stage waveforms at 230 v - 50 hz - full load . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 figure 9. rectifier waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 figure 10. startup waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 figure 11. no-load operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 figure 12. no-load operation - detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 figure 13. transition full load to no-load at 265 vac - 50 hz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 figure 14. transition no-load to full load at 265 vac - 50 hz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 figure 15. short-circuit at full load and 115 vac - 60 hz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 7 figure 16. thermal map at 115 vac - 60 hz - full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 figure 17. thermal map at 230 vac - 50 hz - full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 figure 18. ce peak measurement at 115 vac and full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 figure 19. ce peak measurement at 230 vac and full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 figure 20. pfc coil electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 figure 21. pfc coil mechanical aspect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 figure 22. transformer electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 figure 23. transformer overall drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
list of tables AN3172 4/31 doc id 17230 rev 1 list of tables table 1. overall efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 table 2. light-load efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 table 3. thermal maps reference points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 table 4. evl6599a-90wadp demonstration board: bom list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 table 5. pfc coil winding data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 table 6. transformer winding data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 table 7. document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
AN3172 main characteristics and circuit description doc id 17230 rev 1 5/31 1 main characteristics and circuit description the main features of the smps are: universal input mains range: 90 264 vac - frequency 45 65 hz output voltage: 19 v at 4.75 a continuous operation mains harmonics: acc. to en61000- 3-2 class-d or jeita-miti class-d standby mains consumption: <0.3 w at 230 vac efficiency at nominal load: better than 90 % at full load emi: according to en55022-class-b safety: according to en60950 dimensions: 65x151 mm, 25 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. 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 its output voltage. in this way, the resonant stage can be optimized for a narrow input voltage range, improving the efficiency and the primary side power components.
main characteristics and circuit description AN3172 6/31 doc id 17230 rev 1 1.1 startup sequence as previously indicated, the pfc acts as master and the resonant stage can operate only if the pfc output is delivering its nominal output voltage. therefore the circuit is designed so that at startup the pfc starts first, then the downstream converter turns-on. at the beginning, the l6563h is supplied by the integrated high voltage startup circuit; once the pfc starts switching, a charging pump connected to the pfc inductor supplies both pfc and resonant controllers. once both stages have been activated, the controllers are also supplied by the auxiliary winding of the reso nant transformer, assuring correct supply voltage, even during standby operation. because the l6563h integrated hv startup circuit is turned off, and therefore not dissipative during normal operation, it makes a significant contribution to power consumption reduction once the power supply operates at light-load, in agreement with standby worldwide standards currently required. 1.2 brownout protection brownout protection prevents the circuit from working with abnormal mains levels. it is easily achieved using the run pin (#12) of the l6563h; this pin is connected through a resistor divider to the vff pin (#5) providing the information of the mains voltage peak value. an internal comparator allows ic operations if the mains level is correc t, within the nominal limits. at startup, if the inpu t voltage is below 90 vac (typ.) , circuit operations are inhibited . the l6599a has similar protection on the line pin (#7). it is used to prevent the resonant converter from working with a too low input voltage which can cause incorrect capacitive mode operation. if the bulk voltage (pfc output) is below 380 v, the resonant stage startup is not allowed. the l6599a line pin internal comparator has a hysteresis allowing the turn- on and turn-off voltage to be set 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 a consequent pfc output dip.
AN3172 main characteristics and circuit description doc id 17230 rev 1 7/31 1.3 fast voltage feed forward voltage on the l6563h vff pin (#5) has the same value as the peak value of the voltage on the mult pin (#3) and it is generated by the rc network (r15+r26, c12) connected to vff, completing an internal peak-holding circuit. this signal is necessary to derive information on the rms input voltage to compensate the lo op gain which is mains voltage dependent. in general, if the vff time constant is too small, the voltage generated is affected by a considerable amount of ripple at twice the mains frequency. because the vff signal is fed into the multiplier the excessive ripple causes distortion of the current reference resulting in high thd and poor pf. on the other hand, if the time constant is set 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 new fast voltage feed forward function. as soon as the voltage on the vff pin decreases from a set threshold (40mv 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, but keeping a fast response to mains voltage variations. 1.4 resonant power stage the downstream converter implements the st l6599a, incorporating all the functions necessary to properly control the resonant converter with a 50 percent fixed duty cycle and working with variable frequency. the transformer uses the integrated magnetic approach, incorporating the resonant series inductance. therefore, no additional external coil is needed for the resonance. the transformer configuration chosen for the secondary winding is centre tap and makes use of a couple of power schottky rectifiers p/n stps30h60cfp. a small lc filter has been added on the output, filtering the high frequency ripple. d15, r56, r62, r65, r66, q5, and q6 implement an output voltage ?fast discharge? circuit, quickly discharging the output capacitors when the converter is turned off. it has been implemented to quickly decrease the residual output voltage once the converter is turned off at no-load.
main characteristics and circuit description AN3172 8/31 doc id 17230 rev 1 1.5 output voltage feedback loop the feedback loop is implemented by means of a typical circuit using a tl431 modulating the current in the optocoupler diode. on the primary side, r34 - connecting pin rfmin (#4) to the optocoupler?s phototransistor - closes the feedback loop and its value sets the maximum switching frequency at about 130 khz. this value has been chosen to limit the switching losses at light-load operation. r31, connecting 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. 1.6 l6599a overload and short-circuit protection the current into the primary winding is sensed by the lossless circuit r41, c27, d11, d10, r39, and c25 and it is fed into the isen pin (#6). in the case of overcurrent, the voltage on the pin overpasses an internal comparator threshold (0.8 v), triggering a protection sequence. the capacitor (c45) connected to the delay pin (#2) is charged by an internal 150 a current generator and is slowly dischar ged 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 va lue. 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. th e 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 average input power. 1.7 pfc overvoltage and open-loop protection both circuit stages, pfc and resonant, are equipped with their own overvoltage protections. the l6563h pfc controller monitors its output voltage via the resistor divider connected to a dedicated pin (pfc_ok, #7) protecting the circuit in the case of loop failures or disconnection of the feedback loop divider. in the case where a fault condition is detected, the pfc_ok circuitry latches the l6563h operations and, by means of the pwm_latch pin (#8), it also latches the l6599a, via the dis pin (#8). the converter is kept latched by the l6563h hv circuit that supplies the ic charging the vcc capacitor periodically. to resume converter operation mains restart is necessary.
AN3172 main characteristics and circuit description doc id 17230 rev 1 9/31 1.8 standby power saving the board implements a burst-mode function allowing a significant power saving during light-load operation. the l6599a?s stby pin (#5) senses the optocoupler?s collector voltage which is related to the feedback control and is proportional to the output load. this signal is compared to an internal reference (1.24 v); if the load decreases and the voltage on the stby pin goes lower than the reference, the ic enters an idle state and its quiescent current is reduced. once the voltage exceeds the reference by 50 mv, the controller restarts switching. burst- mode operation load threshold can be programmed by properly choosing the resistor connecting the optocoupler to the rfmin pin (r34). on this board the controller operates in burst-mode if the load falls below ~15 w. the l6563h implements its own burst-mode function. if the comp voltage falls below 2.5 v, the ic stops switching, causing an output voltage decrease, as a consequence the comp voltage rises again and the ic restarts switching. in order to achieve a better load transient response, the pfc burst-mode operation is partially forced by the resonant converter; once the l6599a stops switching due to load drops, its pfc_stop pin pulls down the l65 63h?s pfc_ok pin, disabling pfc switching. thanks to this solution, the pfc is forced into idle state when the resonant stage is not switching and rapidly wakes-up when the downstream converter restarts switching. this solution prevents a significant drop of the bulk voltage in the case of abrupt load rising.
main characteristics and circuit description AN3172 10/31 doc id 17230 rev 1 figure 2. electrical diagram !-v 9df 9#$ 5(9 ' // ' // 5 . 5 . ' %=9& ' %=9& 5 0 5 0 5 5 5 5 4 %&& 4 %&& 5 10 5 10 /  /  & x) & x) 5 . 5 . 5 10 5 10 = 3&%5(9 = 3&%5(9 5 . 5 . ' 6736+&)3 ' 6736+&)3 ' 677+/ ' 677+/ & q) & q) ' 10 ' 10     /  /  & q) & q) ' // ' //   - 0.'6 - 0.'6 5 5 5 5 5 . 5 . ' 6736+&)3 ' 6736+&)3 & q) & q) 5 5 5 5 5 . 5 . ' 10 ' 10 ,19  &203  08/7  &6  9))  7%2  3)&2.  3:0/$7&+  3:06723  581  =&'  *1'  *'  9&&  +96  1&  8 /+ 8 /+ & x) & x) 5 . 5 . & s) & s) 5 10 5 10 5 0hj 5 0hj 5 5 5 5 5 . 5 . & q) & q) ) )86(7$ ) )86(7$ 4 67)101 4 67)101 5 10 5 10 4 %&& 4 %&& 5 0hj 5 0hj ' 6736/$ ' 6736/$ ' // ' // 5 . 5 . 5 . 5 . ' // ' // ' // ' // & 10 & 10 &66  '(/$<  &)  5)0,1  67%<  ,6(1  /,1(  *1'  /9*  9&&  1&  287  +9*  9%227  ',6  3)&6723  8 /$' 8 /$'     8 6)+$ 8 6)+$ 5 0hj 5 0hj 5 0 5 0 4 67)101 4 67)101 5 5 5 5 4 67)101 4 67)101 ' // ' // +6 +($76,1. +6 +($76,1. & x) & x) ' // ' // 5 5 5 5 5 . 5 . 5 . 5 . 5 . 5 . & q) & q) 5 . 5 . 5 . 5 . 4 %&& 4 %&& & q) & q) 5 . 5 . 5 . 5 . 5 . 5 . 5 . 5 . ' // ' // 5 . 5 . -3; -xpshu -3; -xpshu ' // ' // & q) & q)    - 0.'6 - 0.'6 & x) & x) ' // ' // & s) & s) & q) & q) 5 0 5 0 5 . 5 . & s) & s) & q) & q) & q) & q) & q) & q) 5 . 5 . 5 10 5 10 ' %=9& ' %=9& 4 %&& 4 %&& 5 5 5 5 5 0hj 5 0hj 5 0 5 0 5 . 5 . 5 17&56 5 17&56 5 . 5 . & q) & q) 5 . 5 . & q) & q) 4 %&& 4 %&& & q) & q) -3; -xpshu -3; -xpshu 5 . 5 . & q) & q) 5 . 5 . 5 . 5 . & q) & q) & q) & q) -3; -xpshu -3; -xpshu 5 5 5 5    4 10 4 10 & q) & q) ' %=9% ' %=9%  5 0 5 0 5 5 5 5            7  7  & q) & q) 5 10 5 10 ' %=9& ' %=9& & s) & s) +6 +($76,1. +6 +($76,1. & q) & q) & x) & x)      b a a ' *%8-  b a a ' *%8- & q) & q) 5 0 5 0 5 5 5 5 5 0hj 5 0hj ' 10 ' 10 & q) & q) 5 5 5 5 5 . 5 . & 1 & 1     /  /  & x) & x) 5 . 5 . ' 1 ' 1 5 5 5 5 5 . 5 . 5 . 5 . & q) & q) 5 5 5 5 8 7/$,= 8 7/$,= & x) & x) & x) & x) ' 10 ' 10 5 . 5 . 5 5 5 5 & q) & q) 5 . 5 . & q) & q) & x) & x) 5 . 5 . & x) & x) 5 5 5 5 & x) & x)
AN3172 efficiency measurement doc id 17230 rev 1 11/31 2 efficiency measurement epa rev. 2.0 external power supply compliance verification. ta bl e 1 shows the no-load consumption and the overall efficiency, measured at the nominal mains voltages. at 115 vac the average efficiency is 89.96 %, while at 230 vac it is 91.12 %. both values are much higher than the minimum required by epa rev2.0 external power supply limits (87 %). measurements are also given in figure 3 for reference. even at no-load the board performance is superior; maximum no-load consumption at nominal mains voltage is less t han 250 mw only; even this value is significantly lower than the 500 mw limit imposed by the energy star program. figure 3. efficiency vs. output power diagram 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 18.98 0.00 0.00 0.246 ------ 18.97 0.00 0.00 0.235 ------ 100 % load eff. 18.93 4.700 88.97 96.15 92.53 % 18.93 4.700 88.97 98.04 90.75 % 75 % load eff. 18.94 3.526 66.78 72.29 92.38 % 18.94 3.526 66.78 73.40 90.98 % 50 % load eff. 18.95 2.352 44.57 48.72 91.48 % 18.95 2.352 44.57 49.14 90.70 % 25 % load eff. 18.96 1.177 22.32 25.33 88.10 % 18.96 1.177 22.32 25.53 87.41 % average eff. 91.12 % 89.96 %                      3rxw>:@ (iilflhqf\ 0hdv(ii9 0hdvhii9 $yhiiuhtxluhg ".w
efficiency measurement AN3172 12/31 doc id 17230 rev 1 2.1 light-load operation efficiency measurement results are given in ta bl e 2 and plotted in figure 4 . as seen, efficiency is better than 55 % even for very light loads such as 500mw. 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 18.89 13.06 0.247 0.643 38. 37 % 18.89 13.06 0.247 0.62 39.60 % 0.5 w 18.89 26.83 0.507 0.911 55.63 % 18.89 26.83 0.507 0.869 58.32 % 1.0 w 18.89 51.92 0.981 1.415 69.31 % 18.89 51.93 0.981 1.404 69.87 % 1.5 w 18.89 78.90 1.490 2.014 74.00 % 18.89 78.90 1.490 2.010 74.15 % 2.0 w 18.89 105.9 2.000 2.608 76.67 % 18.89 105.9 2.000 2.610 76.61 % 2.5 w 18.89 130.2 2.459 3.145 78.17 % 18.89 130.2 2.459 3.152 78.01 % 3.0w 18.89 157.2 2.970 3.748 79.23 % 1 8.89 157.2 2.970 3.762 78.93 % 3.5 w 18.89 184.2 3.480 4.337 80.23 % 18.88 184.2 3.478 4.358 79.80 % 4.0 w 18.88 211.2 3.987 4.919 81.04 % 18.88 211.2 3.987 4.936 80.76 % 4.5 w 18.88 235.4 4.445 5.415 82.08 % 18.88 235.4 4.445 5.453 81.51 % 5.0 w 18.88 262.4 4.954 5.983 82.81 % 18.88 262.4 4.954 6.031 82.14 %                                  2xwsxw3rzhu>:@ (iilflhqf\>@ 9+]  9+] !-v
AN3172 harmonic content measurement doc id 17230 rev 1 13/31 3 harmonic content measurement the board has been tested according to the european standard en61000-3-2 class-d and japanese standard jeita-miti class-d, at both the nominal input voltage mains. as shown in figure 5 and 6 , the circuit is able to reduce the harmonics well below the limits of both regulations. on the bottom side of the diagrams the total harmonic distortion and power factor have also been measured. the values in all conditions give a clear idea about the correct functioning of the pfc. figure 5. compliance to en61000-3-2 at 230 vac - 50 hz, full load figure 6. compliance to jeita-miti at 100 vac - 50 hz, full load thd = 5.13 % - pf = 0.965 thd = 3.89 % - pf = 0.996 !-v            +duprqlf2ughu>q@ +duprqlf&xuuhqw>$@ 0hdvxuhgydoxh (1&odvv'olplwv !-v             +duprqlf2ughu>q@ +duprqlf&xuuhqw>$@ 0hdvxuhgydoxh -(,7$0,7,&odvv'olplwv
functional check AN3172 14/31 doc id 17230 rev 1 4 functional check the following are some waveforms relevant to the resonant stage during steady-state operation. the selected switching frequency is about 100 khz, in order to have a good trade off between transformer losses and dimensions. the converter operates above the resonance frequency. figure 8 shows the resonant zvs operation. it is worth noting that both mosfets are turned on when resonant current is flowing through their body diodes and drain-source voltage is zero. in figure 9 typical waveforms relevant to the secondary side are represented; it is worth noting that the rectifiers reverse the working voltage and the current flowing through them. the waveforms during the start at 90 vac and full load are shown in figure 10 . it is possible to note the sequence of the two stages; at power-on the l6563h and l6599a vcc voltages increase up to the turn-on thresholds of the two ics. the pfc starts and its output voltage increases from the mains rectified voltage to its nominal value. in the meantime the l6599a is kept inactive by the line pin (#7) until the pfc voltage reaches the set threshold. then the resonant starts operating and the output voltage reaches the nominal level. figure 7. resonant stage waveforms at 115 v - 60 hz - full load figure 8. resonant stage waveforms at 230 v - 50 hz - full load ch1: hb voltage ch2: cf pin voltage ch1: hb voltage ch2: hv fet gate ch3: vcc ch4: res. tank current ch3: lv fet gate ch4: res. tank current
AN3172 functional check doc id 17230 rev 1 15/31 4.1 standby and no-load operation in figure 11 and figure 12 , some burst-mode waveforms are given. as seen, both l6599a and l6563h operate in burst-mode. in figure 11 it may also be noted that pfc and llc bursts are synchronized. in figure 13 and 14 the transitions from full load to no-load and vice versa, at maximum input voltage, have been checked. the maximum input voltage has been chosen because it is the most critical input voltage for transition; in fact at no-load the burst pulses have the lower repetition frequency and the vcc may drop, causing restart cycles of the controller. as seen in figure 13 and 14 , both transitions are clean and there isn't any output voltage or vcc dip. figure 9. rectifier waveforms figure 10. startup waveforms ch1: d23 anode voltage ch2: d24 anode voltage ch1: hb voltage ch2: vout pfc ch3: d23 current ch4: d24 current ch3: vcc ch4: output voltage figure 11. no-load operation figure 12. no-load operation - detail ch1: q4 gate ch2: pfc gate voltage ch1: q4 gate ch2: pfc gate voltage ch3: stby pin ch4: output voltage ch3: stby pin ch4: output voltage
functional check AN3172 16/31 doc id 17230 rev 1 4.2 overcurrent and sh ort-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 referenced to 1.5 v in a second comparator. 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 to discharge the soft-start capacitor css. under output short-circuit, this operation results in a nearly constant peak primary current. with the l6599a the user 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 which shuts down the l6599a and, in the 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 (#2), by means of a capacitor c45 and the parallel resistor r24 connected to ground. when the voltage on the isen pin exceeds 0.8v the first ocp comparator, in addition to discharging css, turns on an internal 150 a current generator that, via the delay pin, charges c45. when 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 13. transition full load to no-load at 265 vac - 50 hz figure 14. transition no-load to full load at 265 vac - 50 hz ch1:hb voltage ch2:vcc ch1:hb voltage ch2:vcc ch3:d23 anode ch4:output current ch3:d23 anode ch4:output current
AN3172 functional check doc id 17230 rev 1 17/31 in figure 15 the narrow operating time with respect to the off time of the converter may be seen; consequently, the average output current, as well as the average primary current, are very low, avoiding over-heating of components and consequent failure. figure 15. short-circuit at full load and 115 vac - 60 hz ch1: hb voltage ch3: delay pin ch4: output current
thermal map AN3172 18/31 doc id 17230 rev 1 5 thermal map in order to check the design re liability, a thermal mapping by means of an ir camera was done. in figure 16 and 17 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 showing high temperature. the ambient temperature during both measurements was 27 c. figure 16. thermal map at 115 vac - 60 hz - full load figure 17. thermal map at 230 vac - 50 hz - full load
AN3172 thermal map doc id 17230 rev 1 19/31 table 3. thermal maps reference points point reference description a l1 emi filtering inductor b d1 bridge rectifier c l2 pfc inductor ? hottest point d d4 pfc output diode e q1 pfc mosfet f - g q3 & q4 resonant hb mosfets h - i t1 resonant power transformer j - k d23 & d24 output rectifiers
conducted emission pre-compliance test AN3172 20/31 doc id 17230 rev 1 6 conducted emission pre-compliance test the following figures are the average measurement of the conducted noise at full load and nominal mains voltages. the lim its shown in the images are en55022 class-b, which is the most popular standard for domestic equipment and has more severe limits compared to class-a, dedicated to it technology equipment. as seen in figure 18 and 19 , in all test conditions the measurements are far below the limits. figure 18. ce peak measurement at 115 vac and full load figure 19. ce peak measurement at 230 vac and full load
AN3172 bom list doc id 17230 rev 1 21/31 7 bom list table 4. evl6599a-90wadp demonstration board: bom list des. part type/ part value case style /package description supplier c1 470 nf 9.0 18.0 p.15 mm x2 - mkp film cap - b32922c3474k epcos c10 1 nf 0805 50 v cercap - general purpose avx c11 2n2f 0805 50 v cercap - general purpose avx c12 1 uf 0805 25 v cercap - general purpose avx c13 680 nf 1206 25 v cercap - general purpose avx c14 68 nf 0805 50 v cercap - general purpose avx c15 47 uf dia6.3x11 (mm) 50 v aluminium elcap - yxf series - 105 c rubycon c16 2n2f 1206 50 v cercap - general purpose avx c17 220 pf 0805 50 v - 5 % - c0g - cercap avx c18 4.7 uf 1206 6.3 v cercap - general purpose avx c19 100 nf 1206 50 v cercap - general purpose avx c2 2n2f dwg y1 safety cap. de1e3kx222m murata c20 2n2f dwg y1 safety cap. de1e3kx222m murata c21 2n2f dwg y1 safety cap. de1e3kx222m murata c22 220 pf 0805 50 v cercap - general purpose avx c23 10 nf 0805 50 v cercap - general purpose avx c24 100 uf dia10x12.5 (mm) 50 v aluminium elcap - yxf series - 105 c rubycon c25 330 nf 0805 50 v cercap - general purpose avx c26 10 uf dia6.3x11 (mm) 50 v aluminium elcap - yxf series - 105 c rubycon c27 220 pf 5x3 mm 500 v cercap - 5mq221kaaaa avx c28 22 nf 5x18 p.15 mm 1000 v - mkp film cap - b32652a0223k000 epcos c29 470 uf dia10x20 (mm) 35 v aluminium elcap - zl series - 105 c rubycon c3 2n2f dwg y1 safety cap. de1e3kx222m murata c30 470 uf dia10x20 (mm) 35 v aluminium elcap - zl series - 105 c rubycon c31 100 uf dia8x11 (mm) 35 v aluminium elcap - yxf series - 105 c rubycon c32 100 nf 0805 50 v cercap - general purpose avx c33 470 pf 0805 50 v - 5 % - c0g - cercap avx c34 100 nf 0805 50 v cercap - general purpose avx c36 1 uf dia6.3x11 (mm) 50 v aluminium elcap - yxf series - 105 c rubycon c37 10nf 0805 50 v cercap - general purpose avx c39 100 nf 0805 50 v cercap - general purpose avx
bom list AN3172 22/31 doc id 17230 rev 1 c4 470 nf 9.0 18.0 p.15 mm x2 - mkp film cap - b32922c3474k epcos c40 100 nf 1206 50 v cercap - general purpose avx c43 4n7f 1206 50 v cercap - general purpose avx c44 10 nf 1206 50 v cercap - general purpose avx c45 220 nf 0805 25 v cercap - general purpose avx c46 n.m. 0805 not mounted c5 470 nf 7.0 x 16.0 p. 22.5 400 v - film cap - b32673z5474 epcos c6 4n7 0805 50 v cercap - general purpose avx c7 100 nf pth 100 v cercap - general purpose avx c8 10 uf dia6.3x11 (mm) aluminium elcap - yxf series - 105 c rubycon c9 68 uf dia. 18x32 mm 450 v aluminium elcap - kxg series - 105 c united chemicon d1 gbu8j style gbu single-phase bridge rectifier vishay d10 ll4148 minimelf sod-80 high speed signal diode vishay d11 ll4148 minimelf sod-80 high speed signal diode vishay d12 n.m. minimelf sod-80 not mounted vishay d13 n.m. minimelf sod-80 not mounted vishay d14 n.m. minimelf sod-80 not mounted d15 bzv55-c15 minimelf sod-80 zener diode vishay d16 ll4148 minimelf sod-80 high speed signal diode vishay d17 n.m. minimelf sod-80 not mounted d18 ll4148 minimelf sod-80 high speed signal diode vishay d19 ll4148 minimelf sod-80 high speed signal diode vishay d2 ll4148 minimelf sod-80 high speed signal diode vishay d20 bzv55-c15 minimelf sod-80 zener diode vishay d21 bzv55-c15 minimelf sod-80 zener diode vishay d22 ll4148 minimelf sod-80 fast switching diode vishay d23 stps30h60cfp to-220fp power scho ttky rectifier stmicroelectronics d24 stps30h60cfp to-220fp power scho ttky rectifier stmicroelectronics d3 1n4005 do-41 general purpose rectifier vishay d4 stth2l06 do-41 ultrafast high volt age rectifier stmicroelectronics d5 ll4148 minimelf sod-80 high speed signal diode vishay d6 ll4148 minimelf sod-80 high speed signal diode vishay d7 ll4148 minimelf sod-80 high speed signal diode vishay d8 bzv55-b27 minimelf sod-80 zener diode vishay table 4. evl6599a-90wadp demonstration board: bom list (continued) des. part type/ part value case style /package description supplier
AN3172 bom list doc id 17230 rev 1 23/31 d9 stps1l60a sma power schottky rectifier stmicroelectronics f1 fuse t4a 8.5x4 p.5.08mm fuse 4a - time lag - 3921400 littlefuse hs1 heat-sink dwg heat sink for d1, q1, q3, q4 hs2 heat sink dwg heat sink for d23, d24 j1 mkds 1,5/ 3-5,08 dwg pcb term. block, screw conn.,pitch 5mm 3 w. phoenix contact j2 mkds 1,5/ 2-5,08 dwg pcb term. block, screw conn.,pitch 5mm 2 w. phoenix contact jpx1 jumper wire bare copper wire jumper jpx2 jumper wire bare copper wire jumper jpx3 jumper wire bare copper wire jumper l1 2019.0002 cm inductor 2x18mh 1.8a magnetica l2 1974.0002 dwg pfc inductor - 0.52mh (x08141-01-b) magnetica l3 1071.0083 dwg 1 uh - 5 a inductor magnetica q1 stf12nm50n to-220fp n-channel power mosfet stmicroelectronics q10 bc847c sot-23 npn small signal bjt vishay q2 bc857c sot-23 pnp small signal bjt vishay q3 stf7nm50n to-220fp n-channel power mosfet stmicroelectronics q4 stf7nm50n to-220fp n-channel power mosfet stmicroelectronics q5 bc847c sot-23 npn small signal bjt vishay q6 bc847c sot-23 npn small signal bjt vishay q7 n.m. sot-23 pnp small signal bjt - not used q9 bc847c sot-23 npn small signal bjt vishay r1 3m3 1206 smd std film res, 1/4 w, 5 %, 250 ppm/c vishay r10 27 k 0805 smd std film res, 1/8 w, 1 %, 100 ppm/c vishay r11 2m2 1206 smd std film res, 1/4 w, 1 %, 100 ppm/c vishay r12 2m2 1206 smd std film res, 1/4 w, 1 %, 100 ppm/c vishay r13 8k2 1206 smd std film res, 1/4 w, 1 %, 100 ppm/c vishay r14 51 k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r15 56 k 1206 smd std film res, 1/4 w, 1 %, 100 ppm/c vishay r16 4k7 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r17 2m2 1206 smd std film res, 1/4 w, 1 %, 100 ppm/c vishay r18 82 k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r19 56 k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r2 3m3 1206 smd std film res, 1/4 w, 5 %, 250 ppm/c vishay r20 0r0 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay table 4. evl6599a-90wadp demonstration board: bom list (continued) des. part type/ part value case style /package description supplier
bom list AN3172 24/31 doc id 17230 rev 1 r21 39 r 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r22 0r47 pth sfr25 axial stand. film res, 0.4 w, 5 %, 250 ppm/c vishay r23 0r68 pth sfr25 axial stand. film res, 0.4 w, 5 %, 250 ppm/c vishay r24 1 meg 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r25 56 r 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r26 1 meg 0805 smd std film res, 1/8 w, 1 %, 100 ppm/c vishay r27 470 r 1206 smd std film res, 1/4 w, 5 %, 250 ppm/c vishay r28 33 k 0805 smd std film res, 1/8 w, 1%, 100 ppm/c vishay r29 1k0 1206 smd std film res, 1/4 w, 5 %, 250 ppm/c vishay r3 1 meg 1206 smd std film res, 1/4 w, 1 %, 100 ppm/c vishay r30 10 r 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r31 33 k 0805 smd std film res, 1/8 w, 1 %, 100 ppm/c vishay r32 47 r 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r33 n.m. 0805 not mounted r34 5k1 1206 smd std film res, 1/4 w, 1 %, 100 ppm/c vishay r35 180 k 0805 smd std film res, 1/8 w, 1 %, 100 ppm/c vishay r36 n.m. 0805 not mounted r37 220 k 1206 smd std film res, 1/4 w, 5 %, 250 ppm/c vishay r38 56 r 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r39 180 r 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r4 4m7 0805 smd std film res, 1/8w, 5 %, 250 ppm/c vishay r40 0r0 1206 smd std film res, 1/4 w, 5 %, 250 ppm/c vishay r41 100 r pth sfr25 axial stand. film res, 0.4 w, 5 %, 250 ppm/c vishay r42 10 k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r43 n.m. 0805 not mounted r44 12 k 1206 smd std film res, 1/4 w, 5 %, 250 ppm/c vishay r45 n.m. 0805 not mounted r46 100 k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r47 1k5 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r48 120 k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r49 39 k 0805 smd std film res, 1/8 w, 1 %, 100 ppm/c vishay r5 10 r 1206 smd std film res, 1/4 w, 5 %, 250 ppm/c vishay table 4. evl6599a-90wadp demonstration board: bom list (continued) des. part type/ part value case style /package description supplier
AN3172 bom list doc id 17230 rev 1 25/31 r50 6k2 0805 smd std film res, 1/8 w, 1 %, 100 ppm/c vishay r51 120 k 0805 smd std film res, 1/8 w, 1 %, 100 ppm/c vishay r52 12 k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r53 2k2 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r54 0r0 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r55 2k7 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r56 18 k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r57 47r 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r58 100 k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r59 100 k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r6 ntc 2r5-s237 dwg ntc resistor p/n b57237s0259m000 epcos r60 10 k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r61 2k7 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r62 4k7 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r65 47k 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r66 2k2 1206 smd std film res, 1/4 w, 5 %, 250 ppm/c vishay r67 n.m. 0805 not mounted r68 n.m. 1206 not mounted r69 4k7 0805 smd std film res, 1/8 w, 5 %, 250 ppm/c vishay r7 1meg 1206 smd std film res, 1/4 w, 1 %, 100 ppm/c vishay r8 1meg 1206 smd std film res, 1/4 w, 1 %, 100 ppm/c vishay r9 62 k 0805 smd std film res, 1/8 w, 1 %, 100 ppm/c vishay t1 1860.0032 dwg, etd34 resonant power transformer magnetica u1 l6563h so-16 high voltage startup tm pfc controller stmicroelectronics u2 l6599ad so-16 improved hv resonan t controller stmicroelectronics u3 sfh617a-4 dip-4, 10.16 mm optocoupler infineon u4 tl431aiz to-92 programmable shunt vo ltage reference stmicroelectronics z1 pcb rev. 1.0 table 4. evl6599a-90wadp demonstration board: bom list (continued) des. part type/ part value case style /package description supplier
pfc coil specification AN3172 26/31 doc id 17230 rev 1 8 pfc coil specification general description and characteristics: application type: consumer, home appliances 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: pq26/20-pc44 or equivalent min. operating frequency: 40 khz typical operating frequency: 120 khz primary inductance: 520 h15 % at 1 khz-0.25 v electrical diagram and winding characteristics: figure 20. pfc coil electrical diagram table 5. pfc coil winding data pins windings dc resistance number of turns wire type 11 - 3 aux 125 m ? 5.5 0.28 mm ? g2 5 - 9 primary 267 m ? 57.5 30x 0.1 mm ? g1     !-v
AN3172 pfc coil specification doc id 17230 rev 1 27/31 8.1 mechanical aspect and pin numbering maximum height from pcb: 22 mm coil former type: vertical, 6+6 pins (pins #1, 2, 4, 6, 7, 10, and 12 are removed) pin distance: 3.81 mm row distance: 25 mm 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 21. pfc coil mechanical aspect manufacturer: magnetica, r. volpini - italy inductor p/n: 1974.0002
transformer specifications AN3172 28/31 doc id 17230 rev 1 9 transformer specifications general description and characteristics: application type: consumer, home appliances 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. with 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: 1200 h8 % at 1 khz-0.25 v (a) leakage inductance: 200 h at 100 khz-0.25 v (b) electrical diagram and winding characteristics: figure 22. transforme r electrical diagram a. measured between pins 2-4 b. measured between pins 2-4 with only one secondary winding shorted table 6. transformer winding data pins winding dc resistance nu mber of turns wire type 2-4 primary 235 m ? 50 30x 0.1 mm ? g1 13-12 sec - a (1) 1. secondary windings a and b are in parallel 9 m ? 5 90x 0.1 mm ? g1 10-9 sec ? b (1) 9 m ? 5 90x 0.1 mm ? g1 5-6 aux (2) 2. aux winding is wound on top of primary winding 94 m ? 4 0.28 mm ? g2         !-v
AN3172 transformer specifications doc id 17230 rev 1 29/31 9.1 mechanical aspect and pin numbering maximum height from pcb: 30mm coil former type: horizontal, 7+7 pins (pins #1 and 7 are removed) pin distance: 5.08mm row distance: 25.4mm figure 23. transformer overall drawing manufacturer: magnetica, r. volpini - italy transformer p/n: 1860.0032
revision history AN3172 30/31 doc id 17230 rev 1 10 revision history table 7. document revision history date revision changes 14-dec-2010 1 initial release
AN3172 doc id 17230 rev 1 31/31 please read carefully: information in this document is provided solely in connection with st products. stmicroelectronics nv and its subsidiaries (?st ?) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described he rein at any time, without notice. all st products are sold pursuant to st?s terms and conditions of sale. purchasers are solely responsible for the choice, selection and use of the st products and services described herein, and st as sumes no liability whatsoever relating to the choice, selection or use of the st products and services described herein. no license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. i f any part of this document refers to any third party products or services it shall not be deemed a license grant by st for the use of such third party products or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoev er of such third party products or services or any intellectual property contained therein. unless otherwise set forth in st?s terms and conditions of sale st disclaims any express or implied warranty with respect to the use and/or sale of st products including without limitation implied warranties of merchantability, fitness for a parti cular purpose (and their equivalents under the laws of any jurisdiction), or infringement of any patent, copyright or other intellectual property right. unless expressly approved in writing by an authorized st representative, st products are not recommended, authorized or warranted for use in milita ry, air craft, space, life saving, or life sustaining applications, nor in products or systems where failure or malfunction may result in personal injury, death, or severe property or environmental damage. st products which are not specified as "automotive grade" may only be used in automotive applications at user?s own risk. resale of st products with provisions different from the statements and/or technical features set forth in this document shall immediately void any warranty granted by st for the st product or service described herein and shall not create or extend in any manner whatsoev er, any liability of st. st and the st logo are trademarks or registered trademarks of st in various countries. information in this document supersedes and replaces all information previously supplied. the st logo is a registered trademark of stmicroelectronics. all other names are the property of their respective owners. ? 2010 stmicroelectronics - all rights reserved stmicroelectronics group of companies australia - belgium - brazil - canada - china - czech republic - finland - france - germany - hong kong - india - israel - ital y - japan - malaysia - malta - morocco - philippines - singapore - spain - sweden - switzerland - united kingdom - united states of america www.st.com


▲Up To Search▲   

 
Price & Availability of AN3172

All Rights Reserved © IC-ON-LINE 2003 - 2022  

[Add Bookmark] [Contact Us] [Link exchange] [Privacy policy]
Mirror Sites :  [www.datasheet.hk]   [www.maxim4u.com]  [www.ic-on-line.cn] [www.ic-on-line.com] [www.ic-on-line.net] [www.alldatasheet.com.cn] [www.gdcy.com]  [www.gdcy.net]


 . . . . .
  We use cookies to deliver the best possible web experience and assist with our advertising efforts. By continuing to use this site, you consent to the use of cookies. For more information on cookies, please take a look at our Privacy Policy. X