NXP Semiconductors AN11524, Примечание к применению

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AN11524 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2015. All rights reserved.
Application note Rev. 1 — 17 February 2015 53 of 54
NXP Semiconductors
AN11524
NXQ1TXA6 Evaluation Board
13. Tables
Table 1. LED status indicator . . . . . . . . . . . . . . . . . . . . . .9
Table 2. NXP components for wireless charger application . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Table 3. Bill Of Materials (BOM) . . . . . . . . . . . . . . . . . . 22
14. Figures
Fig 1. Wireless charging system as defined by Wireless
Power Consortium . . . . . . . . . . . . . . . . . . . . . . . . .3
Fig 2. Overview of the charging pad . . . . . . . . . . . . . . . .5
Fig 3. System efficiency . . . . . . . . . . . . . . . . . . . . . . . . . .6
Fig 4. Switch, buttons and status LED location overview 7
Fig 5. Standby-by power mode switch . . . . . . . . . . . . . . .8
Fig 6. NXQ1TXA6 evaluation board block diagram . . . .12
Fig 7. NXQ1TXA6 charging controller schematic . . . . .16
Fig 8. Half bridge driver stage of coil 1 and current
sense schematic . . . . . . . . . . . . . . . . . . . . . . . . .17
Fig 9. Half bridge driver stage of coil 2 and 3 . . . . . . . .18
Fig 10. Amplitude Shift Keying (ASK) envelope detector
schematic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Fig 11. DC supply schematic . . . . . . . . . . . . . . . . . . . . . .20
Fig 12. NFC schematic . . . . . . . . . . . . . . . . . . . . . . . . . .21
Fig 13. LC tank circuit of coil 1. . . . . . . . . . . . . . . . . . . . .28
Fig 14. Half bridge driver, MOSFET and capacitor
snubber circuits of coil 1 . . . . . . . . . . . . . . . . . . .29
Fig 15. Current sense resistor . . . . . . . . . . . . . . . . . . . . .30
Fig 16. Amplitude Shift Keying (ASK) envelope detector.30
Fig 17. Configuration and voltage measurement . . . . . . .31
Fig 18. Temperature sensing circuit . . . . . . . . . . . . . . . . .32
Fig 19. Tuning capacitor NFC antenna . . . . . . . . . . . . . .32
Fig 20. NXQ1TXA6 charging controller supply
decoupling capacitors . . . . . . . . . . . . . . . . . . . . .34
Fig 21. Decoupling capacitors (left) & GND stitching
vias underneath NXQ1TXA6 (right) . . . . . . . . . . .34
Fig 22. Half bridge driver stage of coil 1 . . . . . . . . . . . . .35
Fig 23. PCB layout of half-bridge driver of coil 1 in
NXQ1TXA6 evaluation board . . . . . . . . . . . . . . .35
Fig 24. DC-to-DC converter . . . . . . . . . . . . . . . . . . . . . . .36
Fig 25. PCB layout of DC-to-DC converter in
NXQ1TXA6 evaluation board . . . . . . . . . . . . . . .36
Fig 26. Current sensing . . . . . . . . . . . . . . . . . . . . . . . . . .37
Fig 27. PCB layout of current sense resistor in
NXQ1TXA6 evaluation board . . . . . . . . . . . . . . .37
Fig 28. EMC common mode choke L601. . . . . . . . . . . . .38
Fig 29. PCB layout of common mode choke L601 in
NXQ1TXA6 evaluation board . . . . . . . . . . . . . . .38
Fig 30. Power stage 1.25 W load. . . . . . . . . . . . . . . . . . .39
Fig 31. Power stage 5 W load . . . . . . . . . . . . . . . . . . . . .40
Fig 32. Power stage, fixed dead-time of 330 ns
(load = 1.25 W) . . . . . . . . . . . . . . . . . . . . . . . . . .41
Fig 33. Typical ASK waveform . . . . . . . . . . . . . . . . . . . . .42
Fig 34. Repeated digital ping . . . . . . . . . . . . . . . . . . . . . .43
Fig 35. NFC tap to power on . . . . . . . . . . . . . . . . . . . . . .44
Fig 36. PCB component placement . . . . . . . . . . . . . . . . .45
Fig 37. PCB top silkscreen . . . . . . . . . . . . . . . . . . . . . . .46
Fig 38. PCB top layer. . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Fig 39. PCB layer 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Fig 40. PCB layer 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Fig 41. PCB bottom layer . . . . . . . . . . . . . . . . . . . . . . . . 50
Fig 42. PCB solder mask . . . . . . . . . . . . . . . . . . . . . . . . 51