Figure 8 Full bridge circuits and coil selection circuits
4.5 Communication
There is bi-way communication between the medium power transceiver and receiver. Communication
from RX to TX: The receiver measures the received power and sends back to transmitter the information
about the required power level. This message is amplitude modulated (AM) on the coil current and sensed
by TX.
The RC circuits (C210, R116, R118, R224), known as DDM, sample the signals from the coil, compress
the signal amplitude, and feed to ADC B-channel of WCT1011A/WCT1013A. The information about the
current amplitude and modulated data are processed by the embedded software routine.
Communication from TX to RX: TX shall negotiate with RX in the negotiation phase if requested by RX.
TX uses FSK Modulation to communicate with RX, and the communication frequency is about 512 times
operating frequency.
4.6 FOD based on power loss
The power loss
𝑃
𝐿𝑂𝑆𝑆
, which is defined as the difference between the Transmitted Power
𝑃
𝑃𝑇
and the
Received Power
𝑃
𝑃𝑅
, i.e.
𝑃
𝐿𝑂𝑆𝑆
=
𝑃
𝑃𝑇
− 𝑃
𝑃𝑅
, provides the power absorption in Foreign Objects, as shown
in
Figure 9
.
C364
22uF
C578
1000PF
R752
51
R751
51
C44
1000PF
R753
51
C579
1000PF
COIL2
Q81
2N7002BKW
1
2
3
Q82
BSS84W
1
2
3
R683
6.8K
C423
0.1uF
R682
100K
R684
100K
C112
0.1uF
C111
0.1uF
C580
0.1uF
C582
0.1uF
DNP
R805
2.00k
D9
BZT52H-C16
A
C
D17
BZT52H-C16
A
C
D13
BZT52H-C16
A
C
R573 1.5K
R575 1.5K
R574 1.5K
COIL1
COIL0
FOD
AC Coil Current
VBAT_SW
R80 5.11K
D14
BAT54SW
1
2
3
R98 5.11K
R88 5.11K
R116
5.11K
R81
33.2K
COILS
R90
33.2K
COIL0_EN
3
TP16
DNP
TP18
DNP
TP17
DNP
TP19
DNP
COIL1_EN
3
SW_GATE0
Q9
IPG20N10S4L-22
2
4
1
3
6
5
SW_GATE1
Q12
IPG20N10S4L-22
2
4
1
3
6
5
COIL2_EN
3
R101 33.2K
TP20
DNP
TP21
DNP
SW_GATE2
COILS
6
R95
7.5K
Q16
IPG20N10S4L-22
2
4
1
3
6
5
R74
7.5K
R84
7.5K
C101
0.022uF
C105
0.022uF
C439
4700pF
C109
0.022uF
C440
4700pF
C441
4700pF
V3.3A
DDM
AC_COIL_CURRENT_OP
3
GAIN_SWITCH
3
TP65
DNP
V3.3A
R118
3.9K
R224
51K
D42
BAS16H
A
C
Q14
PMBT4401
2
3
1
Q10
PMBT4401
2
3
1
Q18
PMBT4401
2
3
1
Q8
PMBTA92
1
2
3
R73
5.11K
Q11
PMBTA92
1
2
3
Q17
PMBTA92
1
2
3
TP35
DNP
C210
4700pF
100V
R83
5.11K
R94
5.11K
C499
1.0uF
IS-
8
L7
2.9OHM
1
2
TP49
DNP
+
-
OUT
IN+
IN-
V+
GND
REF
U21
INA214AQDCKRQ1
1
2
3
4
5
6
R514
0.015
VRAIL
VRAILA
R76
0.015
C94
0.1uF
R79
10.0K
INPUT_CURRENT
3,5
FOD
Inverter Input Current
V3.3A
R376
100
R278
10.0K
VDriv e
R279
10.0K
R201 0
R426
0
HB1A
6
C108
1000pF
C107
1000pF
R89
4.7
R91
4.7
C104 0.1uF
R87
3.32
C181 0.1uF
R85
10
HB1A
R92
3.32
Q13
NVTFS5820NLTAG
1
4
3
2
5
TP7
DNP
1
D12
1PS76SB10
A
C
VRAILA
Q15
NVTFS5820NLTAG
1
4
3
2
5
D59
PMEG2005AEA
A
C
D25
PMEG2005AEA
A
C
C96
0.1uF
50V
C97
0.1uF
50V
C444 4.7uF
AUIRS2301S
U8
VCC
1
HIN
2
LIN
3
COM
4
LO
5
VS
6
HO
7
VB
8
COIL_PWM_HL
3
COIL_PWM_HH
3
VDriv e
R281
10.0K
R280
10.0K
R428 0
C120
1000pF
R427 0
R105 4.7
C121
1000pF
R102 4.7
C118 0.1uF
HB1B
R99
10
C183 0.1uF
R106
3.32
R100
3.32
D18
1PS76SB10
A
C
VRAILA
COIL_PWM_LH
3
COIL_PWM_LL
3
Q20
NVTFS5820NLTAG
1
4
3
2
5
Q19
NVTFS5820NLTAG
1
4
3
2
5
D61
PMEG2005AEA
A
C
D60
PMEG2005AEA
A
C
AUIRS2301S
U9
VCC
1
HIN
2
LIN
3
COM
4
LO
5
VS
6
HO
7
VB
8
C445 4.7uF
R365
100k
R681
2.00k
Q46
2N7002BKW
1
2
3
VRAILA
C98
22uF
R77
20K
R86
20K
C99
22uF
R97
20K
C100
22uF
WCT1011A/WCT1013A Automotive MP-A9 Wireless Charging Application User’s Guide, Rev. 0, 10/2017
10
NXP Semiconductors
