ST STEVAL-WLC38RX - Page 80

Figure 54. STEVAL-WLC38RX PCB layout inner 2 layer .............................................. 47
Figure 55. STEVAL-WLC38RX PCB layout bottom layer .............................................. 48
Figure 56. Power up waveforms of a STEVAL-WLC38RX and STEVAL-WBC86TX setup ....................... 50
Figure 57. Efficiency curves for various misalignments in the X-axis ...................................... 51
Figure 58. Efficiency curves for various misalignments in the Z-axis ......................................52
Figure 59. STEVAL-WLC38RX communication performance at high Z distances .............................53
Figure 60. Thermal performance with a 5 W load (5 V/1 A) after 5 minutes ................................. 53
Figure 61. Thermal performance with a 15 W load (9 V/1.7 A) after 5 minutes ............................... 54
Figure 62. Rx ASK configuration .............................................................. 56
Figure 63. The transition from Low current to Normal current and the effect on modulation ......................57
Figure 64. External NTC connection ............................................................ 58
Figure 65. Default LDO configuration ........................................................... 59
Figure 66. Default LDO drop curve .............................................................59
Figure 67. Cleared Rx FOD tuning registers ...................................................... 60
Figure 68. FOD Tuning tab ..................................................................60
Figure 69. Load adjustment .................................................................. 61
Figure 70. Rx/Tx power difference curve ......................................................... 61
Figure 71. Tuning to obtain a flat BPP FOD curve................................................... 62
Figure 72. Compensated values...............................................................62
Figure 73. Cleared EPP FOD settings........................................................... 63
Figure 74. Tuning to obtain a flat EPP FOD curve................................................... 63
Figure 75. Rf - Qf ........................................................................ 64
Figure 76. Pin connection between host and STWLC38 chip/evaluation board ...............................64
Figure 77. Qi certification flowchart.............................................................69
Figure 78. Temperature Before Power Transfer Maximum 25⁰C on STEVAL-WBC86TX ........................ 71
Figure 79. Maximum Temperature of the Board after 2hours (40.8⁰C) – 5W power transfer STEVAL-WLC38RX ........ 72
Figure 80. Maximum Temperature of the Board after 2hours (42.5⁰C) – 5W power transfer ...................... 72
Figure 81. Maximum Temperature of the Board and Plastic case after 2hours (33.5⁰C) – 5W power transfer .......... 73
UM3154
List of figures
UM3154 - Rev 2
page 80/81