ST STEVAL-WBC2TX70 - Page 77

Contents
1 Getting started ....................................................................2
2 Reference design specifications ...................................................3
3 Overview of the board .............................................................4
3.1 Test points ....................................................................6
3.2 Basic operating modes..........................................................7
3.3 Status LEDs...................................................................7
4 Device description and operation ..................................................8
4.1 System block diagram ..........................................................8
4.2 Power inverter .................................................................8
4.3 ADC .........................................................................8
4.3.1 Bridge voltage monitor ....................................................9
4.3.2 DC-DC current monitor ....................................................9
4.3.3 Bridge current monitor.....................................................9
4.3.4 Ring voltage monitor .....................................................9
4.4 Onboard voltage sources ........................................................9
4.4.1 DC-DC buck converter ....................................................9
4.4.2 The 3.3 V LDO ..........................................................9
4.4.3 The 1.8 V LDO ..........................................................9
4.4.4 Voltage Doubler .........................................................9
4.5 Power up sequence ...........................................................10
4.6 UVLO .......................................................................10
4.7 Chip reset....................................................................10
4.8 Protections overview...........................................................10
4.8.1 Main overcurrent protection (OCP) ..........................................10
4.8.2 Overvoltage protection (OVP) ..............................................10
4.8.3 Voltage drop ...........................................................11
4.8.4 RX Overvoltage protection – static/dynamic OVP, CurrentDrop OVP ................11
4.8.5 Overtemperature protection (OVTP) .........................................11
4.8.6 NTC .................................................................11
4.8.7 QFOD ................................................................11
4.9 Foreign object detection (FOD) ..................................................11
4.9.1 Presence detection ......................................................11
4.9.2 Comparing to reference Q factor............................................12
4.9.3 Power balance .........................................................12
4.10 EPT reason ..................................................................12
UM3286
Contents
UM3286 - Rev 1
page 77/84